IV. FAMILY IV.--VESPERTILIONIDÆ, OR TRUE BATS
The Genus Vespertilio and the Family Vespertilionidæ--Characteristics: Nostrils--Tail--Ears--Dentition--Diet--Distribution--LONG-EARED BAT--Ears--Distribution--Asleep--In Captivity--BARBASTELLE--Characteristics--Distribution--Habits-- Flight--In Captivity--BIG-EARED BAT--TOWNSEND’S BAT--The Genus Nyctophilus--Its true place--Characteristics--GEOFFROY’S NYCTOPHILE--PIPISTRELLE--Distribution--Diet--NOCTULE--Natural Food--Mr. Daniell’s Observations--SEROTINE--PARTI-COLOURED BAT--HAIRY-ARMED BAT--NEGRO BAT--KUHL’S BAT--NILSSON’S BAT--COROMANDEL BAT--THICK-FOOTED BAT--TEMMINCK’S BAT--WELWITSCH’S BAT--NEW ZEALAND BAT--MOUSE-COLOURED BAT--NATTERER’S BAT--DAUBENTON’S BAT--WHISKERED BAT--BLACK AND ORANGE BAT--PAINTED BAT--HARPY BAT--RED BAT--SCHREIBERS’ BAT--BROWN PIG-BAT-- STRAW-COLOURED BAT.
Linnæus, in his “Systema Naturæ,” united all the Bats known to him (with the exception of a single species, which, by a curious perversion of judgment he referred to a distinct genus, and placed in quite a different order) under the single genus Vespertilio. Later writers, finding it necessary, as their knowledge of these animals increased, to divide the Bats into many genera, have gradually, as it were, cut off portions of the old Linnæan genus and given them new names, always retaining the old name for the group which might be considered to include the most typical forms of the original genus Vespertilio, the ordinary Bats of European countries. Of these, only two are noticed in the last edition of the work of the great Swedish naturalist, and even these are now referred to two distinct genera, and the generic name of Vespertilio is now retained by only one of the few species with which Linnæus was acquainted. The genus, however, as at present restricted, contains a great number of species, all of which present the characters of what may be called an average Bat, forming, as it were, the centre (or part of the centre) round which the other groups forming the order may be ideally arranged, and hence it very appropriately bears the old name Vespertilio, as Bat par excellence, constitutes the type of the family Vespertilionidæ, and gives its name to the Vespertilionine alliance. In point of fact the genus Vespertilio and the family Vespertilionidæ may be regarded as the ideal centre of the whole order. As in other groups of the same kind the number of species contained in the family is very considerable, and their structural differences are generally minute, these, indeed, being the characteristics usually presented by what are called typical groups, the study of which is on this account attended with peculiar difficulties.
Except in one Australian genus (Nyctophilus), which has been removed here from among the Megaderms by MM. Tomes and Dobson, the nostrils in the Vespertilionidæ are simple round or crescentic apertures placed at the extremity of the muzzle, and not surrounded by leaf-like appendages. The tail is always long, contained in the membrane between the legs, which it traverses from base to apex, usually leaving a single joint projecting beyond the membrane; the ears are of moderate or large size, are generally separate, and are furnished with large tragi. With regard to the teeth, the upper incisors are separated in the middle by a wide space and placed close to the canines. The number of incisor teeth in the upper jaw varies, being generally four, standing in pairs in the pre-maxillary bones, but in some species there is only one incisor on each side, and this difference may not be associated with any other characters sufficient to justify the generic separation of the species. The lower incisors are almost always six in number; one genus only has four. The canines are of moderate length and strength. The pre-molars again are exceedingly variable; there may be three or two on each side in both jaws, or one on each side in the upper and two in the lower jaw, but the occurrence of two above and three below is very rare. As a rule, when there are more than one pre-molar on each side in the upper jaw, the hindmost of them which is close to the true molars is larger than the one or two nearer the canine (see figure, p. 292), and the latter are often inserted within the line of the row of teeth. The true molars are three on each side in both jaws; they are well-developed, and show the characteristic sharp W-shaped cusps very distinctly.
The Vespertilionidæ are all, so far as is known, strictly insectivorous in their habits. They are found generally distributed throughout the temperate and warm regions of both hemispheres. It is to this family that nearly all the European Bats belong, and it includes all the British species, except the two Horseshoe Bats which have been already described.
THE LONG-EARED BAT.[182]
This common British species is known by the large size of the ears, which are united by their inner margins over the middle of the crown of the head. Hence this group, the Plecoti of authors, may be regarded as naturally forming a sort of stepping-stone from the Megaderms, with their extravagant dermal developments, to the more commonplace “Vespertiliones.” In the Long-eared Bat this character is very striking, the ears being nearly seven-eighths as long as the head and body. The organs are quite thin and membranous, resembling those of the Megaderms already described, and they are traversed longitudinally by three thin threads of cartilage, which apparently serve by their elasticity to support the ears in an erect posture. From the middle thread of cartilage the inner margin of the ear is bent in, forming a sort of fold. A little above the base there is on each ear a small lobe, so placed that when the ears are erect these lobes touch each other. The outer margin of the ear ends opposite the base of the tragus, which is very long, tapering upwards. The tail, which is nearly as long as the head and body, is contained, all but the extremity of the last vertebra, in the ample interfemoral membrane, along the posterior margin of which the spurs extend fully half-way from the heel to the tip of the tail on each side. The fur in the Long-eared Bat is long, thick, and soft; the hairs are blackish at base, tipped above with brown, with a reddish or greyish tinge, which appears to vary with the age of the individuals, and beneath with pale brownish-grey. All the membranes are dusky, usually with a reddish or brownish tinge. The head and body in this species measure about one inch and five-sixths in length, and the tail is about one-sixth of an inch shorter. Its expanse of wing is ten inches.
This Bat occurs in nearly all parts of Europe and in North Africa, extending eastwards throughout Central Asia, but apparently not south of the Himalayas. Specimens from Northern Africa, even up to the fifth Cataract of the Nile, and from the desert regions about the Mediterranean and Caspian Seas, are described as having the fur paler and more ashy in colour, and the membranes also paler than those from more humid localities.
The Long-eared Bat is common, and pretty generally distributed in Britain, but is not so abundant or so well known as some other species. This may, perhaps, be in part due to the fact that it is a nocturnal species, coming abroad later than its fellows, and continuing on the wing in pursuit of the moths, which appear to constitute its chief prey, during the whole of the night. “At all hours,” says Mr. Bell, “through the dead of the night, and in the darkest nights, in the open fields or elsewhere, we have heard the shrill chatter of the Long-eared Bat over our heads, its voice, once known, being easily recognised from that of any other species.” Mr. Bell suggests, what may probably be true, that the great development of the ears in this (and probably other species) may be connected with the habit of flying late at night. It chiefly frequents the open country, taking up its abode in the roofs of tiled houses, especially in country villages, in which situations the Bats pass the day during the summer, suspended in clusters from the walls and timbers by the claws of their hind feet, and the whole winter cosily packed between the tiles and in various holes and corners. It also exhibits a predilection for church towers. When sleeping, the long delicate ears are not generally left exposed, but are folded down under the wings, where they are carefully tucked away. This is commonly the case when the Bat has settled down for its day’s sleep, and always occurs during hibernation. When the ears are thus disposed of, the earlets or tragi still project from the head, giving the little creature the appearance of possessing only a pair of short pointed ears (see figure).
In captivity the Long-eared Bat soon becomes very tame and familiar. These Bats will fly about the room, play with each other, and may soon be induced to feed from the hand. “One kept by Mr. James Sowerby,” as stated by Mr. Bell, “when at liberty in the parlour, would fly to the hand of any of the young people who held up a fly towards it, and, pitching on the hand, take the fly without hesitation. If the insect was held between the lips, the Bat would then settle on its young patron’s cheek, and take the fly with great gentleness from the mouth; and so far was this familiarity carried, that when either of the young people made a humming noise with the mouth, in imitation of an insect, the Bat would search about the lips for the promised dainty.” From an observation made by Mr. Tomes (Bell’s “British Quadrupeds,” second edition, p. 76), it would appear that the Long-eared Bat, even in freedom, habitually captures at least some of its food in a somewhat similar manner. He says that “having occasion to rise early--about three in the morning--on opening the window of his bedroom, a Bat of this species was seen actively engaged around the sprigs of a spindle-tree which extended across the window. It was in bloom at the time, and was surrounded by a cloud of Microlepidoptera, on which the Bat was feeding. As this took place scarcely four feet from the open window it was easy to see the whole proceeding, and to determine with certainty the manner in which the food was taken. With scarcely an exception, the moths were picked from the leaves while resting there, only one or two being taken on the wing. While thus occupied the Bat hovered much after the manner of the Kestrel, and the ears were bent outwards so much as to curl down the sides of the face, appearing more like two huge cheek-pouches than ears, no part of them appearing of greater elevation than the crown of the head.”
On the ground the progression of the Long-eared Bat is very peculiar. Bats in general run along the ground with the head and body in a nearly horizontal position, but the Long-eared Bat carries the fore part of its body raised, and advances by a series of jerks, first on one side and then on the other.
Several species nearly related to the Long-eared Bat have been described under various generic names. Antrozous pallidus is an inhabitant of North America, Histiotus velatus is found in Brazil, and Otonycteris Hemprichii occurs in Nubia.
THE BARBASTELLE.[183]
The Barbastelle is another British Bat belonging to the same group of the family Vespertilionidæ as the Long-eared Bat, but forming the type of a very distinct genus. The ears, instead of being elongated into great membranous organs half as long as the body of the animal, are only of moderate size, but they are united by their inner margins in the middle of the forehead a little in front of the eyes. The outer margin sweeps round upon the face, on which it terminates above the upper lip, so that the eye is almost completely surrounded by the ear. The tragus is triangular and pointed. The nostrils, as in Plecotus, open on the upper surface of the nose in front of a naked space, and from each nostril a deep groove runs down to the edge of the upper lip. The muzzle is short and blunt, giving the animal rather a surly aspect; the tail is nearly as long as the body, and enclosed in the interfemoral membrane, except the extreme tip; and the teeth are as in the Long-eared Bat.
The Barbastelle is by no means a common Bat in England, where it seems to be confined to the Southern and Midland Counties, extending as far north as Northamptonshire and Warwickshire. It is found in France, rarely in Belgium and Germany, in Italy, Scandinavia, and Russia. In the southern part of the last-mentioned country it appears to be more abundant than elsewhere, especially in the Crimea, on the south coast of which it is said by M. Demidoff to be very common. It is said by Mr. Bell to occur in Nepaul, but the specimens referred to by him probably belong to the Darjeling Bat (Synotus darjelinensis) of Mr. Hodgson.
This curious little Bat measures about two inches in length of body, and its tail is about a quarter of an inch shorter. The expanse of its wings is ten inches. The cheeks are covered with black hair, which forms a sort of moustache. The ears are irregular in form, their tips being slightly truncated, and their outer margins sweeping in so as to form a notch, from which five or six folds run about half-way across the ear. The eyes are almost concealed by the black hairs on the cheeks. The fur is long and soft, and of a brownish-black colour, with whitish tips, which are longer on the hairs of the lower surface. The membranes are dusky black.
In its habits the Barbastelle seems to be rather solitary; both in its places of repose and in its evening flights it is generally seen alone. It sometimes takes up its abode in caverns, but almost any place of retreat will suit it. Thus it may be found in the crevices of walls or trees, in the roofs of sheds, behind shutters, and in fact in almost any situation that offers it a chance of concealment. Its flight is peculiar, being a lazy, desultory sort of flutter, performed as if with no particular object; and according to Mr. Bell it is in the habit of approaching evening promenaders “so closely that the flutter of its wings may be heard, and even the cool air thrown by their movement felt upon the cheek.” In captivity the Barbastelle is rather timid, and does not become familiar with its keeper after the fashion of its near relation, the Long-eared Bat; and when confined with other Bats it shows a certain sullenness of disposition, and an inclination to keep apart from its companions. A specimen received in winter by Mr. Bell from a chalk cavern at Chislehurst was very restless when awake, and was constantly biting at the wires of his box, as if endeavouring to escape. “When suffered to fly about the room, he flew very low, and less actively than any other under similar circumstances; and he was fond of lying before the fire on the hearthrug, where he appeared quite to luxuriate in the warmth.”
In the second edition of “Bell’s British Quadrupeds,” a beautiful variety of this Bat from Alcester, in Warwickshire, is mentioned, having “the fur of the under parts, from root to tip, strongly tinged with purplish-red, or rose-colour.” The authors also state that they have seen a perfectly white specimen of the species, and one in which the head and neck were of the ordinary dark colour, whilst the rest of the body was pure white. In both these specimens, which were young, the membranes were nearly white.
THE BIG-EARED BAT.[184]
Two North American Bats, allied to the Long-eared Bat and the Barbastelle, have been formed into a distinct genus by Dr. Allen. They have the ears very large, with the outer border carried forward beneath the tragus, which is nearly half as long as the ear, tapering upwards, and furnished near the base on the outer side with a small circular lobe standing almost at right angles to the tragus. The sides of the nose bear large excrescences, which join with the inner margins of the ears. There are three pre-molars in the lower jaw, instead of two, as in Plecotus and Synotus.
The Big-eared Bat is a small species an inch and four-fifths long, with a tail nearly of equal length. It is clothed with a long, fine, and soft fur, the hairs of which are blackish at the base, with dusky-brown tips on the upper surface, and greyish tips below. This Bat is an inhabitant of the Southern Atlantic States of the Union.
Townsend’s Bat (Corynorhinus Townsendi) is a very similar animal, but is a little longer, and has the face larger and broader and the facial crests more prominent. Its ear and head are shown in the annexed figures. The fur is brown above, with the bases of the hairs only a little darker than the tips, lighter beneath, and slightly rusty towards the base. It inhabits the central parts of the United States (Missouri, Utah).
GEOFFROY’S NYCTOPHILE.[185]
The genus Nyctophilus includes a small number of Bats belonging to the Australian region, which, on account of their possession of a rudimentary nasal appendage, have usually been placed with the Megaderms or the Rhinolophidæ. But apart from the presence of the nose-leaf, which is of very simple structure, the characters of these Bats are in such close agreement with those of the Vespertilionidæ, that there seems to be no doubt that this is their true position. They appear to be most nearly related to Plecotus.
The nasal appendages are very simple, consisting of a transverse front piece placed immediately above the nostrils, and having its upper margin straight, and a second portion, also transverse, placed at a greater distance from the first than the latter from the nostrils, and thickly clothed with short bristly hairs. The ears are large, ovoid, united at their bases by a membrane which runs across the top of the head, and furnished with a short broad tragus. The dentition differs from that of the allied genera. There are two separated incisors and only one pre-molar on each side in the upper jaw, and the lower jaw has only two pre-molars on each side. Thus the dental formula is--incisors, (1–1)/6, canines, (1–1)/(1–1), pre-molars, (1–1)/(2–2), molars, (3–3)/(3–3).
Geoffroy’s Nyctophile, which appears to be one of the commonest species, as also the one first described, is a small Bat, the head and body measuring rather more than two inches in length, and the tail more than one inch. The heel-spurs are half an inch long. The body is covered with long, thick, and soft fur, which is usually brown above and brownish-grey beneath, the hairs on both surfaces being black at the base, tipped above with olive-brown, and on the under surface with brownish-white. The membranes are dark brown. The species is an inhabitant of Western Australia, where it is abundant. These Bats are sometimes found in great numbers in the hollow spouts of the gum-trees, from which they emerge in the evening to flit around the shrubs and smaller trees in search of insects.
Three other species of this genus are known, one of which, although originally described as from Timor, and named N. timoriensis, is only known to occur in Western Australia; another is from New South Wales, and the third from Van Diemen’s Land.
THE PIPISTRELLE.[186]
The commonest and most generally distributed of the British species is the Pipistrelle,[187] to which the local country name of Flittermouse is considered by Mr. Bell to be specially applicable. In this and the allied species forming the genus Vesperugo, the outer margin of the ear sweeps round on the cheek below the tragus, so as nearly to reach the angle of the mouth, and there is a small membranous lobe outside of the spur which runs from each heel into the interfemoral membrane. There are four incisor teeth in the upper and six in the lower jaw.
The Pipistrelle is of a reddish-brown colour above, paler beneath. The ears are about two-thirds of the length of the head, somewhat triangular, rounded at the tips, with the upper part of the outer margin deeply concave; the earlet, or tragus, is nearly half as long as the ear, and is of an oblong form with the apex rounded; the wings extend down to the base of the toes, and their membrane, like that of the ears, is of a dusky tint.
This Bat seems to occur abundantly in all parts of the British islands. It is also common on the continent of Europe, as far north as the central parts of Sweden, and southwards to the shores of the Mediterranean, extending thence eastwards through Russia into Siberia and Central Asia, but not passing to the south of the Himalayas. It is essentially an inhabitant of temperate regions. Its favourite resting-places in Britain, according to Mr. Jenyns, are the crevices of decayed brick walls, the cracks of old door-frames, and behind the pipes which are attached to buildings for carrying off rain-water; and Mr. Bell describes it as taking shelter under the roofs of houses, and in crevices of buildings of every description, either inside or out. According to the second edition of Mr. Bell’s work, a specimen has been taken from a hole in the thatch of a low shed in a brick-field, another from a pile of hurdles in a stackyard, whilst a third was observed issuing from the spout of a disused wooden pump, and one was captured from behind a piece of loose bark on a pollard willow near Stratford-on-Avon.[188] The Pipistrelle is thus rather indiscriminate in its choice of a residence, and this may perhaps be due to the fact that its period of winter torpidity is shorter than that of any other species found in the countries which it frequents. In Great Britain it appears on the wing as early as the middle of March, and does not retire for its annual sleep until the winter season has decidedly set in; indeed, Mr. Gould once shot a specimen in the middle of a bright sunny day just before Christmas. Its food consists principally of small insects, especially Gnats, Midges, and other small two-winged flies, but it does not confine itself exclusively to such diet; raw meat possesses such attractions for it that this Bat not unfrequently makes its way into places where this is kept, and may be found clinging to a joint, and making a hearty meal upon it. In confinement, also, the Pipistrelle readily takes small pieces of raw meat as a substitute for its ordinary insect food, and it will become so tame as to take its nourishment from the fingers. On the ground the Pipistrelle runs with considerable ease and quickness, and Mr. Bell states, in opposition to the assertions of certain writers, that it can rise from a flat surface without difficulty. He says:--“We have often seen the Pipistrelle rise from a plane surface with a sort of spring, instantly expand its wings, and take flight. This was repeated by a single individual several times in the course of an hour, and without the slightest appearance of difficulty or effort; it was, on the contrary, evidently a natural and usual action.” The same writer remarks that this Bat climbs with considerable agility, and in connection with this notices a peculiarity in the use of the tail which appears to have escaped other observers, namely, that it is used as an organ of prehension. The last joint of the tail projects a little beyond the interfemoral membrane, and “not only does the animal employ the tail in horizontal progression, in which case it assists in throwing forward the body, by being brought into contact with the ground on either side alternately, corresponding with the action of the hinder foot on the same side; but in ascending and descending a rough perpendicular surface, this little caudal finger holds by any projecting point, and affords an evident support. This is particularly conspicuous when the Bat is traversing the wires of a cage, in which situation the fact was first observed.”
THE NOCTULE.[189]
The Great Bat, or Noctule, is another well-known British species, although far from being so abundant as the preceding. It is, however, even more widely distributed, being found in nearly all parts of the Eastern hemisphere, except the extreme north, but in tropical regions, according to Mr. Dobson, it seems to inhabit only the high grounds. In England it ranges as far north as Yorkshire. Its head and body measure about three inches in length, and its wings are about fourteen inches in expanse. Its fur is of a reddish-brown colour, nearly uniform throughout; the ears are ovate-triangular, shorter than the head, broad, and having the outer margin produced down upon the cheek below the level of the angle of the mouth; the earlet is short, not more than one-third the length of the ear, broad, with the outer margin rounded and the inner one concave. The wing-membranes reach only to the ankle-joint, and there is a distinct lobe outside each of the spurs.
The Noctule seems to prefer for its resting place the hollows of old trees, and generally to avoid buildings, although instances of its taking up its abode in or about the latter are not wanting. It is gregarious in its habits, considerable numbers often retiring together to the same hiding-place. Thus, in the second edition of Bell’s “British Quadrupeds,” a good many Noctules are said to have been “dislodged from a hole made by the Green Woodpecker in an elm by the insertion of a flexible stick;” and at Rugby, in Warwickshire, in a grove of old oaks, their excrement has been observed to form so thick a layer as to darken the ground under some of the oldest trees. Pennant states, on the authority of Dr. Buckworth (Buckhouse?), that one hundred and eighty-five of these Bats were taken in one night from under the eaves of Queen’s College, Cambridge, followed by sixty-three on the second night, when the supply seems to have been nearly exhausted, as only two were captured on the ensuing evening.
The natural food of the Noctule consists of insects, and its jaws are sufficiently powerful to enable it to devour even such large and horny Beetles as Cockchafers, which, indeed, seem to constitute its favourite food. It is, in fact, most active during the period of the year when these insects abound, for White, who first noticed its occurrence in Britain, states that he never saw it at Selborne before the end of April, or later than the end of July. In Warwickshire, however, it has been observed as early as the 12th of March, and as late as the 18th of September. It flies very high, and on this account was named by White Vespertilio altivolans. Its course through the air is rapid and straight, and accompanied by a continual sharp and shrill cry, which ceases only during the capture and consumption of its insect prey. It is described by White as emitting a rancid and offensive odour.
Mr. George Daniell, in a paper communicated to the Zoological Society in 1834, published some notes on the behaviour of this Bat in captivity, which are particularly interesting from the description they contain of the birth of a young Noctule. Mr. Daniell obtained four females and one male of this species on the 16th of May, 1834. The male was very savage, biting the females, and breaking his teeth upon the wires of the cage in his attempts to escape. He refused to feed, and died on the 18th of May. The females, although at first sulky, fed after a time upon small pieces of raw beef, which they seemed to prefer to insect food. One of them died on the 20th, and two others on the 22nd; the survivor, which fed by preference upon the breasts and livers of fowls, lived on for rather more than a month. It passed the day suspended by the hind feet at the top of the cage, and came down in the evening to feed, which it did sometimes most voraciously; the quantity eaten exceeding half an ounce, although the weight of the animal itself was only two drachms. It rejected flies, but ate parts of some Cockchafers that were given to it. The animal was rather careful in cleaning itself, using the posterior extremities as combs, with which the hairs were parted on either side from head to tail, forming a straight line down the middle of the back. The membrane of the wing was cleaned by passing the nose through its folds. On the 23rd of June Mr. Daniell observed his Bat to be very restless, and this condition lasted for about an hour, the animal remaining as usual suspended by the hinder extremities. Suddenly “she reversed her position, and attached herself by her anterior limbs to a cross wire of the cage, stretching her hind limbs to their utmost extent, curving the tail upwards, and expanding the interfemoral membrane, so as to form a perfect nest-like cavity for the reception of the young, ... which was born on its back, perfectly destitute of hair, and blind. The mother then cleaned it, turning it over in its nest; and afterwards, resuming her usual position, placed the young in the membrane of her wing. She next cleaned herself, and wrapped up the young one so closely as to prevent any observation of the process of suckling. At the time of its birth the young was larger than a new-born Mouse; and its hind legs and claws were remarkably strong and serviceable, enabling it not only to cling to its dam, but also to the deal sides of the cage. On the 24th the animal took her food in the morning, and appeared very careful of her young, shifting it occasionally from side to side to suckle it, and folding it in the membranes of the tail and wings. On these occasions her usual position was reversed. In the evening she was found dead; but the young was still alive, and attached to the nipple, from which it was with some difficulty removed. It took milk from a sponge, was kept carefully wrapped up in flannel, and survived eight days; at the end of which period its eyes were not opened, and it had acquired very little hair.”
From these observations of Mr. Daniell it appears that the period of gestation in the Noctule exceeds thirty-eight days, and they are of very considerable interest with respect to the general history of the Chiroptera, at any rate of the present family, for it is most probable that the conduct of this female Noctule on this interesting occasion is closely followed by other maternal Vespertilionidæ at the arrival of their “little strangers.” Moreover, the fact of the production of only a single young one, and the finding of only a single embryo in each of the three females which died soon after they came into Mr. Daniell’s possession, taken in conjunction with observations to the same effect which have been made upon the female of the Pipistrelle, and of several other species of Bats, would seem to show that the Bats in general produce only one at a birth.
THE SEROTINE.[190]
Three other species of Vesperugo occur in Britain. One of these, the Serotine (V. serotinus), is nearly as large as the Noctule, and closely resembles that species in some respects in its habits. The head and body in the Serotine are about two inches and two-thirds in length; the ears are ovate-triangular, and a little shorter than the head; the tragus is a little more than one-third the length of the ear; and the extremity of the tail projects nearly a quarter of an inch from the membrane. The fur, which is soft and silky, is usually chestnut-brown above, and yellowish-grey beneath, but it is liable to vary more or less; British specimens being sometimes of a greyish tinge, whilst some from the Asiatic side of the Ural Mountains are described as having the upper parts yellowish cream-colour, and the lower surface yellowish-white. Like the preceding species, the Serotine is widely distributed, being found apparently over a great part of Europe, and throughout the temperate regions of Asia, at least as far east as the Himalayas; whilst specimens have been identified with it, which were brought from the northern parts of Africa, as far south as the mountains near the Gaboon. In England it is found only in the South-eastern counties, and is said to occur in the neighbourhood of London. Folkestone and the Isle of Wight are other recorded localities. In France it is not uncommon, frequenting the forests, and flying amongst the lofty trees; it is also found in the timber yards of Paris. Like the Noctule it is late in making its appearance in the spring, and it also flies late at night, whence its specific name. In France it bears one young one about the end of May.
THE PARTI-COLOURED BAT.[191]
Of the Parti-coloured Bat (Vesperugo discolor) only a single specimen has been taken in England, and it was obtained by Dr. Leach many years ago at Plymouth. The probability is, as indicated by Mr. Bell, that this individual must have been conveyed to Plymouth in the rigging of some vessel. On the continent of Europe it is found chiefly in Russia and Germany, but does not extend into Belgium, Holland, and France. It has also been obtained from Central Asia and from the Himalayas. This Bat is of the same size as the Serotine, and is perhaps the handsomest of the European species, the fur of the upper surface being of a fine chestnut or deep brown colour, with the extreme tips of the hairs pale, or even sometimes white, giving the fur a finely-marbled appearance, while that of the lower parts is grey at the base and white at the tips, with a reddish-brown patch on the middle of the chest and belly. The ears are about two-thirds the length of the head, oval, and directed outwards (see figure), their outer margin produced nearly to the angles of the mouth, and their inner margin with a projecting lobe at the base. The Parti-coloured Bat is said to haunt towns, and to come abroad early in the evening.
The Hairy-armed Bat (Vesperugo Leisleri) also for a long time founded its claim to be regarded as a British species upon a single specimen, but of late years it has occurred at several localities in the midland counties of England and in Ireland. It is a little smaller than the preceding species, the head and body measuring only two inches and a half in length, and is characterised especially by having a broad band of hair upon the wing-membrane along the whole course of the fore-arm. The fur is bright chestnut above and brownish-grey on the under surface. It is found generally about villages, and appears to take up its residence in buildings. On the continent it seems to be pretty generally distributed, and it extends, like the preceding species, over the temperate parts of Asia. Specimens have also been brought from the Azores and Madeira, and it is believed to live in Algeria.
Several other species of this genus have an almost equally wide range. Thus one that may be called the Negro Bat (Vesperugo maurus) is found along the whole of the great axis of elevation of the Old World from the Pyrenees into China, and even extends southwards into India, Cochin China, and Java. This species has a sooty-brown or deep-black fur, with the tips of the hairs greyish. Kuhl’s Bat (Vesperugo Kuhlii) is found throughout India, and in Persia and Southern Europe, to Madeira. It is rather a small species, about an inch and three-quarters long, with black fur, tipped for one-fourth of its length above with yellowish-brown or dun-colour, and beneath with ash-colour. Another species, Nilsson’s Bat (Vesperugo borealis), which has the highest northern range of any species of the order, stretches right across the old continent, from Scandinavia and Germany as far south as the Hartz Mountains, to the Altai Mountains and North China. This species has a dark-brown fur, tipped with yellowish-brown above and with ash-colour beneath. It is about two inches long.
THE COROMANDEL BAT.[192]
Besides the preceding, which are common to Europe, there are a good many purely Asiatic species, mostly belonging to the Indian region and its islands. Mr. Dobson enumerates eighteen such species, the most generally distributed of which is the Coromandel Bat (Vesperugo abramus), which appears to represent in the southern parts of Asia the Pipistrelle of the more temperate regions. It is rather larger than the Pipistrelle, measuring an inch and three-quarters in length, and the outer margin of the ears is straight, or very slightly concave; the fur is dark-brown, tipped with light yellowish-brown above, and sooty-brown with pale tips beneath, and the head, face, and neck are yellowish-brown. This species is common in India and Ceylon, and extends thence through China to Japan, occurring also in several islands of the Eastern Archipelago.
Mr. Swinhoe says that it is a common house Bat at Nagasaki, in Japan. He also found it abundantly in Hainan, and, treating it as the common Chinese Bat, quotes the description of the Bat from the Chinese Gazetteer, in which, as is usual with Chinese writers, the animal is classed with birds. This choice description is as follows:--“Peenfoo, or Bat, shaped like a Mouse, has thin flesh-wings uniting the four legs, and extending to the tail. In winter stows away; in summer comes out. In daytime lies prostrate; in night flies. One name for it is Foo-yeh, or Belly-wings. It is now called Feishoo, or Flying Mouse.”
THE THICK-FOOTED BAT.[193]
In this species, which inhabits Northern India, Tenasserim, the Andaman and Philippine Islands, and the Islands of Java and Sumatra, the bases of the thumbs and the soles of the feet are furnished with broad, fleshy pads, which on the feet form nearly circular discs, and are doubtless organs of adhesion, analogous to the more perfect sucking discs present in an American member of the family (Thyroptera tricolor). These organs probably assist the Bat in clinging to the under surfaces of large leaves and fruit, a habit which is common to many tropical species of Bats. It is remarkable that in this species, as in the Thyroptera, the claws on both the thumbs and the toes, although acute, are very small.
The Thick-footed Bat is about an inch and three-quarters in length of body, with a tail an inch and a quarter long. It is covered with a fine, dense, and moderately long fur, of a bright reddish-brown colour above, paler beneath. There is only one pre-molar on each side in the upper and two in the lower jaw, and this character, with the presence of the foot-pads, serves to distinguish the sub-genus Tylonycteris of Professor Peters, to which this species belongs.[194]
TEMMINCK’S BAT.[195]
A few species, very nearly allied to the preceding, form the genus Scotophilus, in which the outer margin of the ear likewise comes down to the level of the angle of the mouth, but there are only two incisor teeth in the upper jaw, instead of four as in Vesperugo. These are stout-bodied Bats, with the muzzle nearly naked, the limbs strong, and the wing-membranes very thick and leathery, and scarcely encroached upon by hair. They are confined to the Eastern Hemisphere, and generally to its warmer parts, the species being found in Africa, Southern Asia and its islands, and in Australia. The best-known species is Temminck’s Bat (Scotophilus Temminckii), which enjoys a wide range from India and Ceylon eastward through Burmah and Southern China to the Eastern Archipelago, extending to the Moluccas and Philippine Islands. It is rather more than three inches in length, and varies considerably in colour, but is generally dark olive-brown above, and reddish or yellowish-white beneath. The fur, as throughout the genus, is short and close. The ear is peculiar in its form, and its outer margin sweeps round on the cheek and terminates in a convex lobe; the tragus is narrow and pointed, and considerably curved forwards and inwards. Temminck’s Bat is very abundant in the countries which it inhabits, and is one of the most prominent species of the group, seeing that it lives in large bands, often of several hundred individuals, in the roofs of houses and in hollow trees, and that it flies very early in the evening, in fact before the commencement of twilight. Temminck says that it feeds principally on White Ants (Termites).
The Harlequin Bat (Scotophilus ornatus), another Indian species, is remarkable for its coloration, which is a pale tawny-brown, curiously variegated with white spots. It has been obtained in India, Burmah, and Yunnan.
WELWITSCH’S BAT.[196]
This curious Bat, originally described by Dr. Gray from a specimen sent from Angola by the late Dr. Welwitsch, is especially remarkable for the brightness and variegation of its colours. The general tint of the fur is brown, the hairs being black at the base, with brown tips, which are longer and paler on the hairs of the lower surface, rendering the fur of that part paler than that of the back. The head also is pale, and the muzzle shows an orange tint, as do the ears, which are longer than the head, and rather acute, with a long pointed tragus, reaching nearly half-way up the ear. But the most striking peculiarity of the species consists in the colouring of the wings, which are yellowish-brown, dotted with black near the body, and beyond this chiefly blackish-brown, with numerous yellow dots arranged more or less regularly in curved lines, while a broad band of brownish-orange, bearing a few black dots, follows the course of the fore-arm, and gives origin at the wrist to three other bands of the same colour, one running down the margin of the wing and enclosing the first and second fingers, the other two following the course of the third and fourth fingers, and thus breaking the dark ground colour of the wing into three triangular patches. The occurrence of this peculiar mode of coloration in a Bat is the more remarkable as it is reproduced in at least two quite distinct species, namely, the Oriental Vespertilio formosus and Kerivoula picta, and in all these must probably subserve the same purpose, which Mr. Dobson with much justice supposes to be the protection of the animal by assimilating its appearance to that of withered leaves. The arms and legs in Welwitsch’s Bat are yellow, but the feet are black. The interfemoral membrane is yellowish-brown, with a few black dots, especially towards its margins. The length of the head and body is about three inches. Of the habits of this Bat nothing is recorded.
THE NEW ZEALAND BAT.[197]
Two species of Bats have been ascertained to inhabit New Zealand, and both present characters which isolate them systematically, just as much as their distant insular habitation does absolutely. The present species was discovered by J. R. Forster, the naturalist who accompanied Captain Cook, and described by him under the name of Vespertilio tuberculatus. It has short rounded ears; there are cutaneous lobes at the angles of the mouth, and three true molars on each side in both jaws. The upper incisors are in pairs, the inner ones much larger than the outer, and are separated from the canines; the pre-molars are small and pointed, and the molars of the ordinary form in the allied genera. The tragus is short, rather broad, and rounded at the tip. The wing-membranes spring from the base of the toes; the interfemoral membrane is large, and contains the long tail, of which the tip only projects; and the heel-spurs are long, extending one-third of the distance between the heel and the tip of the tail.
In its form and general proportions this Bat resembles the common British Pipistrelle, as also in the characters of the skull. In its dentition it has a still closer affinity to an Australian species, Gould’s Bat (Scotophilus Gouldii). The fur is of a blackish-brown colour on the head and back, becoming chestnut-brown on the rump; the lower surface is of a similar colour, but browner, and becomes reddish-brown towards the tail. The hairs are of one colour throughout their length. The length of the head and body is rather more than two inches, and that of the tail about an inch and a half. This Bat inhabits the middle island of New Zealand. Nothing appears to be known of its habits.
THE MOUSE-COLOURED BAT.[198]
The genus Vespertilio, as now restricted, comprehends a very considerable number of species distributed in nearly all parts of the world. It differs from Vesperugo in having the outer margin of the ear terminated opposite the level of the tragus, and not produced towards the angle of the mouth, and is further characterised by the nostrils being simple and crescent-shaped, and scarcely projecting from the muzzle. Eight species inhabit Europe, and five of these are found in Britain.
The Common Bat of the continent of Europe, the Mouse-coloured Bat of Prof. Bell (Vespertilio murinus), is a large species more than three inches and a half in length. Its fur is of a pale reddish-brown colour above and greyish-white beneath, but with the bases of all the hairs black; the head is long, the ears oval, narrowed towards the apex, as long as the head, and the tragus is nearly half as long as the ear, narrow, pointed, with its inner margin quite straight. The membranes are of a yellowish-brown colour. Vespertilio murinus is met with in the north-western Himalayas, and extends thence through Syria into Northern Africa. It is common in Central and Southern Europe, but in England is one of the rarest Bats; in fact the only known British-caught specimen was taken (most conveniently) in the gardens of the old British Museum. Its claim to be considered indigenous rests, therefore, upon a very insecure foundation. In many parts of Europe, however, this species is exceedingly abundant, and lives by hundreds together, chiefly in church-towers and other similar localities, issuing forth in the evening to prey upon the insects which fly at that time. Moths are said to be its favourite victims, and the harder parts of these insects, with portions of the wings, are found unaltered in the Bat’s excrement. Notwithstanding their social habits, these Bats are exceedingly quarrelsome; they fight vigorously with their sharp teeth and the claws of their thumbs, often tearing each other severely, and even breaking the slender bones in the wings of their adversaries.
NATTERER’S BAT.[199]
The Reddish-grey Bat, or Natterer’s Bat (Vespertilio Nattereri), is an undoubted native of this country, although it appears to be local in its distribution. It has been taken near London, at Swaffham in Cambridgeshire, at Colchester and Norwich, at Chislehurst (hibernating in a chalk cavern), and at Arrow, near Alcester, in Warwickshire. It has also occurred in Ireland. It inhabits the continent of Europe from the Ural Mountains westward to Belgium and France, and in the south occurs on the shores of the Mediterranean. Apparently its range does not extend into Asia.
Natterer’s Bat has the fur reddish-grey above, and whitish beneath, the hairs of which it is composed being dark towards the base, with light tips. The ears are oblong-ovate, and about as long as the head, and the tragus is nearly two-thirds the length of the ear; but the most distinctive character of the species consists in the margin of the interfemoral membrane, from the tips of the spurs to that of the tail, being fringed with a row of long stiff hairs. In its social habits this Bat seems to agree with the Mouse-coloured Bat, but is much more amiable in its disposition. Specimens received by Mr. Bell from a cavern in the chalk at Chislehurst (where they were found hibernating in company with several other species) were kept alive for a time by feeding them on bits of raw meat, and exhibited “great familiarity of disposition, not only by their friendliness towards their companions, but by their readiness in taking food from the hand, and in allowing themselves to be interfered with without evincing fear or anger.” These Bats were active in their habits, running and climbing about the cage with great agility. The sociability of character of Natterer’s Bat is still more strikingly shown by the curious description given in the second edition of Bell’s “British Quadrupeds” of a colony observed in the roof of Arrow Church, near Alcester. In a dark retreat, between the ceiling of the church and the tiled roof, “the Bats were seen adhering, by all their extremities, to the under surface of the row of tiles which forms the crest or ridge of the roof (partly supported, however, by the upper tier of roof-tiles on which the ridge-tiles rested), and others clinging to them, until a mass was made up three or four inches thick, six or seven wide, and about four feet in length. It would be wrong to call this their place of repose, as they presented a most singular scene of activity, the constant endeavour of those outside being to penetrate the mass, probably for warmth; and to do this they were continually poking their noses between those nearest to them, and then forcing in their bodies, to be in their turn again pushed to the outside. In this manner a regular bickering was kept up in the whole mass. However, they seemed to be very gentle, and to have no idea of biting or otherwise annoying each other.”
DAUBENTON’S BAT.[200]
Daubenton’s Bat is another species which is almost confined to Europe. It is generally distributed over that continent from Finland and the Ural Mountains to Ireland and the Mediterranean, but is only of doubtful occurrence in North-western Asia. It is about two inches in length; its ears are about three-fourths the length of the head, oval, with the outer margin sinuated, and the inner margin folded in; the tragus is narrow, rather obtuse at the apex, and about half the length of the ear; the tail is longer than the body; the fur is usually reddish-brown, but sometimes dark brown or greyish-brown above, and ash-grey beneath; and the wing-membranes show a slight reddish tinge.
The habits of this Bat are very peculiar. It usually takes up its residence in church-towers and other buildings, but sometimes in hollow trees, and always in the vicinity of water, its active life being passed in flying over the surface of water. Its flight is not very rapid, and is performed by means of very slight but rapid strokes of the wings. It flies usually close to the surface, and from time to time dips its nose into the water, probably for the purpose of drinking. This Bat is gregarious in its habits, great flocks being generally seen flying about together, and considerable numbers always inhabit the same retreat. In confinement it seems to be very delicate, and does not live long; but it is quiet and gentle in its behaviour, and will drink milk from the palm of the hand, and feed upon small pieces of meat and house flies. The latter, according to Mr. Bell’s editors, are favourite morsels with these Bats, and “it was curious,” they say, “to see them poke their little noses between the fingers for flies which were concealed there. A fly put on a smooth table was always a tempting but tantalising bait for them, for the Bats, in attempting to take hold of it, almost invariably pushed it to the outside of the table, from which it fell and was lost.” In Britain, Daubenton’s Bat has been taken in various localities, extending as far north as Aberdeenshire; and in Ireland it has occurred in Donegal and Kildare.
THE WHISKERED BAT.[201]
The Whiskered Bat inhabits all Central Europe from the Alps to Finland, and from Russia to Ireland. It is also found among the Himalayas, and is said by Schrenck to occur in the Amoor country, so that its distribution in Asia is probably rather wide. In England its occurrence has been recorded in Cambridgeshire, Northamptonshire, and Warwickshire, at Colchester and at Chislehurst, and in Ireland in the county of Clare. The Whiskered Bat is a small species, the head and body measuring only one inch and two-thirds in length. Its colour is dark chestnut-brown above, ashy-brown beneath; the ears bend outwards and have the outer margin notched; the tragus is half the length of the ear; the face is very hairy, and the hairs on the upper lip are longer than the rest, so as to form a moustache, whence the name of the species. This Bat is solitary, being generally found singly in its resting-places, which consist of holes in walls, the roofs of houses, and, in general, any dark crevice or corner. It resembles the Pipistrelle in its flight and general habits, and is doubtless often mistaken for that species.[202]
THE BLACK AND ORANGE BAT.[203]
This species, which has been referred by various authors to different genera, is especially remarkable for its peculiar coloration. The muzzle is of a conical form; the ears ovate, with the rounded tips projecting outwards, so as to render the outer margin concave for some distance; the tragus long, narrow, and obtusely pointed; the fur is soft and thick, of a reddish-yellow colour above, and pale yellowish beneath; and the wing-membranes, which are very broad, are singularly variegated with bright orange and brownish-black. The dark portions form irregularly triangular patches on the membranes between the second and third and third and fourth fingers, and between the fourth finger and a line drawn from the wrist to the ankle. All the rest of the membrane, including the ears and interfemoral membrane, are orange, this colour forming narrow bands along the course of the fingers, and also extending more or less in the form of specks and streaks over the dark patches. The length of the head and body in this Bat is from two inches and a third to two inches and a half, and the expanse of the wings twelve inches and a half. It is found in the Himalayan region in Nepaul and at Darjeling, in the Khasia Hills, and in China at Shanghai, Kiang, and Amoy.
This beautiful Bat presents a remarkable resemblance in coloration to another Eastern species (the Painted Bat), to which we shall presently refer; and, indeed, by some zoologists it has been placed in the same genus (Kerivoula) with the latter. Mr. Swinhoe, in his memoir on the Mammals of Formosa (Proc. Zoo. Soc., 1862, p. 357), refers to a species which he regards as allied to the Black and Orange Bat and the Painted Bat, but which was most probably the former, in the following terms:--“The body of this Bat was of an orange-brown, but the wings were painted with orange-yellow and black. It was caught, suspended head downwards, on a cluster of the round fruit of the Longan tree (Nephelium longanum). Now this tree is an evergreen, and all the year through some portion of its foliage is undergoing decay, the particular leaves being, in such a stage, partially orange and black. This Bat can therefore at all seasons suspend from its branches, and elude its enemies by its resemblance to the leaf of the tree. It was in August when this specimen was brought to me. It had at that season found the fruit ripe and reddish-yellow, and had tried to escape observation in the semblance of its own tints to those of the fruit.” This example of “protective mimicry,” if such is really its nature, is reproduced, as already stated, in the Painted Bat, and also, as remarked by Mr. Dobson, in Welwitsch’s Bat from Western Africa.
THE PAINTED BAT.[204]
A small group of Bats, nearly related to the preceding, is distinguished as forming a distinct genus under the name of Kerivoula, originally proposed and founded on a native Cingalese name by the late Dr. Gray. These Bats have the apertures of the nostrils perfectly circular; the first and second pre-molars in the upper jaw nearly as large as the third pre-molar, the ears large and funnel-shaped, the outer portion sweeping forward very much, and the spur of the heel long and stout, and curved backwards.
The Painted Bat (Kerivoula picta) has been already referred to as one of the species remarkable for their coloration. It is a small species, having the head and body only an inch and a half to an inch and three-quarters long. Its fur is of a deep orange colour above and paler beneath. The ears and interfemoral membrane, and the portions of membrane in front of the bones of the arm, are likewise deep orange, as are also the basal portions of the wing-membranes, broad bands bordering all the bones of the arms and fingers, and the hinder margin of the portions of membrane between the feet and the extremities of the fourth fingers, and the remainder of the wing-membranes being occupied by large triangular patches of deep black, more or less variegated with orange spots and streaks.
This remarkable Bat is found in many parts of the Peninsula of India, and also in Ceylon, Burmah, Sumatra, and Java; in fact, Mr. Dobson thinks that it is probably distributed in all parts of tropical Asia. It haunts the forests, and is very active in pursuit of insects. When disturbed in the day-time, according to Dr. Jerdon, it looks more like a Butterfly or a Moth than a Bat, and we may easily believe that the character and arrangement of its colours will give it an exceedingly un-batlike aspect. For its place of repose it selects the folded leaf of the plantain, and, according to Dr. Kelaart, its native Cingalese name of “Kehelvoulha” (from which the generic name is derived) signifies “Plantain Bat.” The other species of this genus present nothing remarkable.
THE HARPY BAT.[205]
The Harpiocephali are a curious group of Bats almost entirely confined to the Himalayan region, only two species being found elsewhere, namely, in the islands of Java and Sumatra, and one of these is also a Himalayan species. The most striking character of the genus is one which it displays in common with the Harpy Fruit Bat (Harpyia Pallasii) already described, namely, the remarkable prominence of the nostrils, which project in a tubular form on each side of the muzzle. These Bats are further distinguished by the hairiness of the upper surface of the interfemoral membrane, which is sometimes entirely, and never less than half covered with hair, the wing-membrane being also generally hairy for a greater extent than in other allied species.
The Harpy Bat (Harpiocephalus harpia) is about two inches and a half long, with a tail nearly two inches in length. Its fur is very soft and silky, that of the upper surface brownish or whitish-grey, with the tips of the hairs red, producing a bay or reddish-brown tint on the back, whilst the head, neck, and shoulders show more of a greyish cast; and that of the lower surface entirely grey. The membranes are of a reddish-brown colour, clothed above with hairs of the same tint on the basal part of the wings, and over the whole surface of the interfemoral membrane. The ears are broad, and rounded at the tip. This fine Bat has been observed in India, at Darjeling, and the Khasia Hills; it is also an inhabitant of Java and Sumatra.
The skull and jaws in the Harpy Bat exhibit indications of considerable strength; in fact, the general aspect of the skull is very Dog-like, and the large size of the coronoid process of the lower jaw would seem to indicate that the whole is intended to form a powerful masticating apparatus. This notion is further borne out by the character of the teeth, which are very stout, the molars being furnished with short, blunt cusps, thickly coated with enamel, and admirably fitted to crush the hard cases of the Beetles, which appear, from the contents found in its stomach, to constitute the principal food of this Bat. Mr. Dobson remarks that “as we become better acquainted with the habits of these animals, it will probably be found that the food of this species is restricted to certain species of Coleoptera possessing extremely hard cases, which would effectually resist the feebler, although more acutely-pointed teeth of other Bats inhabiting the same localities. The form of the teeth, the great development of the coronoid process, and the shortness of the mandible, are all evidently subservient to the same object, and have been modified simultaneously to suit the food of the animal.”
THE RED BAT.[206]
The genus Atalapha, to which the Red Bat of North America belongs, is very nearly related to Nycticejus, and in fact its species have been not unfrequently placed in that genus. In general characters the two groups closely agree, but the head in Atalapha is more elevated, and the interfemoral membrane is wholly, or to a very considerable extent, clothed with hair. This latter character, with the presence of only two incisors in the upper jaw, serves at once to distinguish the species of this genus, which are confined, like those of Nycticejus, to the Western hemisphere.
The Red Bat is generally distributed over all the temperate parts of North America, even extending, according to Peters, as far north as the Aleutian islands, whilst Geoffroy and Temminck state that it occurs in Cayenne and Surinam. The head and body are usually rather less than two inches long, and the tail is of about the same length; the expanse of wing is from eleven to twelve inches. There are two pre-molar and three molar teeth on each side. The ears are irregularly rounded, and the outer margin runs round upon the cheek, and forms a distinct lobe below the origin of the tragus, which is about half the height of the ear, and turns inwards at the point. The fur is long and silky, and is generally of a light russet colour, tinged with yellow, darker and richer on the back. The colour, however, varies, specimens being met with showing fawn-coloured and even yellowish-ashy tints. At each shoulder there is a tuft of white hair. The interfemoral membrane is entirely covered above, and half covered beneath, with hair of the same colour as that on the body. The membranes are of a rich brown colour, and the ears and lips are marked with yellow. The above furnishes indications only of the general effect produced, but each hair is dark lead-colour at the base, then yellowish-brown, passing into dark or bright red or chocolate colour, with the extreme tip generally white. Northern specimens usually show the darker tints, while those from warmer regions are more frequently of a bright red colour.
Dr. Allen quotes the following anecdote, illustrating the force of the maternal instinct in this little Bat:--A lad had caught a young Red Bat, which he took home with him. “Three hours afterwards, in the evening, as he was conveying it to the museum in his hand, while passing near the place where it was caught, the mother made her appearance, and followed the boy for two squares, flying around him, and finally alighted on his breast, such was her anxiety to save her offspring. Both were brought to the museum, the young one firmly adhering to its mother’s teat. This faithful creature lived two days in the museum, and then died of injuries received from her captor. The young one being but half grown, was still too young to take care of itself, and died shortly after.”
The Hoary Bat (Atalapha cinerea) is larger than its congener, the Red Bat, measuring from two to three inches in length, and from twelve to fifteen inches in expanse of wing. Its colours, also, are quite different. The head and neck are of a faded yellow colour, the back brownish chocolate or umber smoky fawn-colour, and the lower surface fawn-colour, darker on the breast. All the hairs are tipped with white, which gives the animal the peculiar ashy tinge alluded to in its name. The whole upper surface of the interfemoral membrane, and about one-third of its lower surface, are clothed with hair. The Hoary Bat is distributed over the whole of North America, as far north as Canada and the Hudson’s Bay Territories.[207]
SCHREIBERS’ BAT.[208]
Several species of Long-tailed Bats, peculiar to the Eastern hemisphere, have been formed into the genus Miniopterus, which differs from all the preceding forms by having the crown of the head abruptly and very considerably raised from the face, and the upper incisors in pairs separated not only from each other, but from the canines. They have the ears separate, with their outer margins extending forward nearly to the opening of the mouth; the nostrils simple; the first phalanx of the second finger very short; and the tail as long as the head and body, and entirely enclosed within the interfemoral membrane.
Schreibers’ Bat, the type of this genus, is very remarkable for its extraordinary geographical range; for, according to the determinations of Messrs. Tomes and Dobson, it extends from Japan through the Eastern Archipelago to Australia, and westward of these localities through Burmah and Ceylon to Asia Minor, and thence into Southern Europe. It is also generally distributed in Africa, and occurs in Madagascar. On the continent of Europe it is found as far north as Switzerland and Lower Austria.
The species varies considerably in the colour of its fur. The basal half of the hairs is always dark, either brown, greyish-black, or black, with the extremities sometimes of nearly the same tint, but generally lighter, varying from a light grey, even becoming whitish on the lower surface, to reddish-grey and reddish-brown. Specimens from tropical localities are generally dark in colour. The ears are much shorter than the head, and sweep almost completely round the eye (whence the name of “blepotis” was given to the Eastern form by M. Temminck), terminating near the angle of the mouth in a small square-ended lobe. The tragus is much shorter than the ear, about twice as long as broad, and rounded at the tip. The total length of this Bat is about four inches, half of which goes to the head and body, and the remainder to the tail. Schreibers’ Bat is an inhabitant of caves. It was originally obtained from the caverns of the Banat, but occurs generally throughout Southern Europe. In the East it is also said by M. Temminck to find a retreat in caves and clefts in the rocks. It is very common in Java, but rarely appears in the open country.[209]
THE BROWN PIG BAT.[210]
This is another of the forms occupying the border-land between the families of Vespertilionidæ and Emballonuridæ, and assisting to unite the whole of the simple-nosed Insectivorous Bats in one great series. In the form of the head, and in the dentition, it resembles especially Natalus and Furia. The wing-membranes are continued down the toes to the base of the claws; the tail is long, and enclosed, except the last joint, in the interfemoral membrane, which is supported by long heel-spurs, beyond which there are membranous lobes; and the thumbs are free and clawed, and, like the soles of the feet, furnished with curious adhesive discs. The toes consist of only two phalanges each, as in the genus Phyllorhina. The genus was described by MM. Lichtenstein and Peters under the name of Hyonycteris (Pig Bat), in allusion to the elongated and truncated form of the muzzle, which has somewhat of a Pig-like aspect.
The singular adhesive organs mentioned above as occurring on the thumbs and feet of this Bat, are described in considerable detail by Mr. Dobson in the “Proceedings of the Zoological Society.” He remarks that they constitute the only known instance of the possession by Mammals of prehensile organs at all resembling the sucking-discs of the Cephalopodous mollusca. “On the inferior surface of the thumb,” he says, “from the base of the first phalanx, ... corresponding to the position of the ball of the thumb in other Bats, arises, by a short peduncle, a hollow suctorial disc about one-tenth of an inch in diameter. On the sole of the foot a similar but considerably smaller disc is placed, not in the same relative position, however, as in the thumb; for it covers the metatarsal bones, not the bases of the first phalanges of the toes.” According to a Spanish writer, Señor Jimenez de la Espada, these discs were used by the animal to fasten itself to the fingers as it tried to bite, producing the same feeling as a key or thimble when applied to the tongue after sucking out the air; and it is added, “the muscular arrangement is such as to allow the animal to vary the diameter of the organ; and by their means the animals attached themselves to the sides of the box in which they are kept, although, when sleeping, they suspended themselves by the claws like other Bats.” Mr. Dobson, however, by careful examination of the structure of the discs, convinced himself that the Spanish zoologist was mistaken in ascribing any muscular arrangements to these curious organs, which consist exclusively of an unusual development of the skin and subcutaneous tissue, amongst which a radiating cartilaginous structure probably gave rise to the notion of a special muscular apparatus. Mr. Dobson indicates further that the discs of the feet are supplemented by several small projections from the hinder border of the heel-spur, which are known to occur in no other species of Bat, and he regards the whole of these peculiarities as indicating that the animal is specially adapted for climbing, like the New Zealand Bat (Mystacina tuberculata), and that in all probability both these species are in the habit of capturing the insects on which they feed while crawling over the branches of trees.[211]
The Brown Pig Bat (Thyroptera tricolor) is an inhabitant of South and Central America. Its head and body are rather more than an inch and a half long, and the tail about an inch and a quarter. The fur is of a cinnamon-brown colour, paler beneath, and the wings dusky brown.[212]
THE STRAW-COLOURED BAT.[213]
In this curious little Bat, as in Furipterus and Miniopterus, which with it form the links of connection between the two families of simple-nosed Insectivorous Bats, the crown of the head is also much elevated and separated from the muzzle by a strong depression. The nostrils are placed quite at the tip of the nose, and close to the upper lip (see figure, p. 312), the chin has a semicircular double row of warts, the ears are large, broad, somewhat pointed at the tip, which is turned outwards, so as to make the outer margin appear excavated, whilst below it sweeps round upon the side of the face as a free lobe, and the tragus, which is short, broad, and fleshy, rises from the end of a short stalk projecting horizontally from the inside of the opening of the ear. The wings are of moderate length, and rather broad, and are attached to the ankle in a most singular manner. Their point of attachment is not, as usual in Bats, on the outside, but on the inside of the ankle, so that a narrow strip of membrane has to cross over the terminal portion of the shank. The thumbs are free; the legs and tail are long and slender; the latter, which consists of only seven joints, is longer than the head and body of the animal, and is almost entirely enclosed in the ample interfemoral membrane, the posterior margins of which are supported by long spurs springing from the heels. All the membranous parts, including the ears, are thickly marked with dotted lines. There are four incisor teeth in the upper jaw, placed in pairs, and separated by a space from the canines. There are three pre-molars in both jaws. (Dental formula--incisors, (2–2)/6, canines, (1–1)/(1–1), pre-molars, (3–3)/(3–3), molars, (3–3)/(3–3).)
The Straw-coloured Bat measures about four inches in total length, fully one-half of which is occupied by the tail. It is clothed with a moderately-long fur, of a brownish-yellow colour, paler on the lower surface. The membranes are reddish-brown. It is an inhabitant of South and Central America.
V. EMBALLONURINE ALLIANCE
FAMILY V.--EMBALLONURIDÆ, OR THICK-LEGGED BATS.
Characteristics of the Emballonuridæ, or THICK-LEGGED BATS--CUVIER’S FURY--The Genus Saccopteryx--STRIPED SACK-WINGED BAT--The Pouch or Sac in the Wing-membrane--Dentition--MOUNTAIN BAT--TOMB BAT--Origin of its Name--Dentition--The peculiar Sac or Pouch under the Chin--Other Species of the Genus (note)--EGYPTIAN RHINOPOME--Difficulty of assigning its true place in the System--Characteristics--GREAT HARE-LIPPED BAT--Seba’s Description--Linnæus’s Mistake--Dentition--Distribution--The Genus Nyctinomus--CESTONI’S BAT--PALE CHESTNUT MASTIFF BAT--Distribution--Habits--SMOKY MASTIFF BAT--Habits--COLLARED BAT--Hideous Ugliness--Characteristics--NEW ZEALAND SHORT-TAILED BAT--Characteristics--Mr. Dobson on the Wing-membrane, Thumb, and Foot.
This family is the first of the second great group into which Mr. Dobson divides the ordinary Bats, and it includes many forms which are almost as typically Bats as the Vespertilionidæ themselves. As in the Vespertilionidæ the nostrils are simple, that is to say, they are quite destitute of foliaceous appendages, except in one curious genus (Rhinopoma), which has a very small nose-leaf. The character of the folding of the first phalanx of the middle finger in repose upon the upper surface of the metacarpal bone has already been mentioned as distinguishing the members of this alliance generally. It is subject to two exceptions in the present family, being extended in a line with the metacarpal bone, in the same way as in the Vespertilionine Bats, in the curious genus Noctilio, and folded beneath the metacarpal in the equally singular genus Mystacina. In the latter genus, moreover, the middle finger has three phalanges, the number of these bones in all other Emballonuridæ being two. The legs are short and stout, and have the two bones of the shank (tibia and fibula) nearly equally developed; the tail has its basal portion enclosed within the interfemoral membrane, but perforates this on the upper surface, at or beyond the middle, and is usually continued as a free organ for a considerable distance beyond this point; and the upper incisor teeth are generally two in number.
The members of this family, which are insectivorous in their habits, are chiefly confined to the tropical and sub-tropical regions of both hemispheres. A single species inhabits Europe, and one is found in New Zealand.
CUVIER’S FURY.[214]
A curious little South American Bat, described by F. Cuvier under the name of Furia horrens, is of interest to the zoologist as one of the links between the two great groups of Microchiroptera. It is remarkable for the form of its muzzle, which is somewhat Pig-like, cut off and turned up at the extremity, and bristling all over with hairs. The tragus is in the form of a barbed arrow-head; and the thumb is exceedingly short, and entirely enclosed within the membrane, only the claw being left free. The canine teeth in the upper jaw are very peculiar, showing four points. This Bat is only about an inch and a half long. Its eyes are large and prominent, its nostrils surrounded by slightly-raised borders, and its chin bears eight white warts, seven running round the lip, while the eighth stands in the centre. The fur is soft, thick, and black. A second species of the genus, also from South America, is described by Mr. Tomes under the name of Furipterus cœrulescens. Its fur is of a slaty blue tint.
THE STRIPED SACK-WINGED BAT.[215]
The genus Saccopteryx is readily distinguished from all others by the existence in the membrane in front of the arm (the shoulder membrane or antebrachial membrane) of a singular sac or pouch, which is situated on the lower surface of the membrane near the elbow, and opens at the upper surface in a corresponding position.[216] This sac is not peculiar to the males, but occurs in both sexes. There are in the upper jaw only two incisor teeth, which are small and separated by an interval from each other and from the canines (see figure above). The lower jaw has six incisors in a close row. The canines are strong and sharp, especially the upper ones; the first pre-molar is small, the second larger and acute, and the three true molars are large and strongly tubercular. The ears are of moderate size, and furnished with well-developed tragi. The interfemoral membrane occupies the whole space between the legs, and is stretched by a pair of long spurs, between which the hinder margin is either straight or incurved, and the basal portion of the short tail is enclosed in the membrane, from the upper surface of which its tip projects. The species of this genus are all American.
The Striped Sack-winged Bat is rather a small species, measuring about two inches and a quarter from the tip of the nose to the base of the tail. Its fur is tolerably long, full, and lustrous, that of the upper surface dark brown, with two white streaks running down from the shoulders to the hinder extremity of the body; the lower surface is paler, the hairs having ashy tips. It is an inhabitant of Surinam.[217]
THE MOUNTAIN BAT.[218]
This species is an example of a small series of Bats which, although nearly allied to the preceding, are inhabitants of the Eastern hemisphere, the known species of the genus Emballonura being found in the Eastern Archipelago and Australia, and in some of the oceanic islands of the Pacific. The ears in this genus are somewhat triangular in form, with the outer margin sinuated; the tragus is truncated, slightly widened at the tip, and furnished with a small blunt projection at the base of the outer margin; the muzzle is somewhat elongated, with curved nostrils situated in a rounded pit; the interfemoral membrane is large, and stretched by long spurs. There are four incisor teeth in pairs above, and six below, and two pre-molars and three molars on each side in each jaw.
The Mountain Bat (Emballonura monticola) is a very small creature, measuring only an inch and a half in length, with a tail nearly half an inch long, the extremity of which protrudes from the back of the interfemoral membrane. The wing-membrane springs from the ankle. The general colour of the fur is a chocolate-brown, lighter on the lower surface, the hairs being in all parts chocolate-brown at the tips. Their basal portions are yellowish-white on the back and brown on the belly. The membranes are entirely naked.
This Bat is an inhabitant of Java, Sumatra, Borneo, and the Philippine Islands, where it lives in the wildest and most solitary regions of the mountains. It is social in its habits, considerable troops of them sleeping suspended from the surfaces of perpendicular rocks, under the shade of the overhanging trees and shrubs. They are said to be unsavoury little beasts, their presence being perceptible, even at a considerable distance, by the strong and disagreeable odour with which they contaminate the air.[219]
THE TOMB BAT.[220]
During the French expedition to Egypt under the first Napoleon, M. Geoffroy, one of the savants who accompanied the army, discovered a species of Bat inhabiting the tombs of the ancient kings of Egypt, which differed in many important characters from all previously known Bats. He made it the type of a new genus, to which he gave the name of Taphozous, in allusion to its tomb-haunting habits. Some other species have since been discovered in various parts of the Eastern hemisphere.
The Taphozoi have a rather short and broad head, with a tapering muzzle, its breadth behind the eyes being due to the wideness of the zygomatic arches. The ears are separate, and their outer margins sweep round upon the cheek, terminating near the angle of the mouth; the tragus is short, somewhat widened at the apex, so as generally to have a hatchet shape; the wings are long and narrow, and the interfemoral membrane is ample, and stretched by very long spurs, between the tips of which its hinder margin is concave; the base of the tail is enclosed in the membrane, from which its tip projects. The teeth, especially the canines and upper true molars, are powerful, and the latter show the W-shaped cusps very distinctly. There are three molars and two pre-molars in each jaw, but in the upper jaw the hindmost molar is reduced to a narrow transverse plate, as shown in the figure, and the first pre-molar is so small as scarcely to project above the gum. In the lower jaw there are four small incisors; but in the upper jaw the pre-maxillary bones are represented only by cartilage, which in the young, and sometimes in adult animals, bears a pair of minute teeth, separated from each other by a wide space, but these apparently frequently drop out as the animal advances in age. In consequence of this structure, the skull presents a peculiar appearance. The intermaxillary cartilage being lost, the front of the face presents a deep notch between two projecting processes which bear the canine teeth, and even during life the lower jaw extends further forward than the upper one, so that its incisor teeth press only against the upper lip.
Another curious character presented by most of these Bats is the existence under the chin of a peculiar pouch (see figure, p. 316), which sometimes occurs in both sexes, although smaller in the females, and is sometimes altogether wanting in the latter. In some, the place of this sac, which is evidently of a glandular nature, seems to be represented by a group of small pores. The purpose of this peculiar arrangement is not clearly known; but from the greater development of the organ in the males of those species which possess it, it would appear to be of a sexual character. The peculiar wing-pouches which characterise the genus Saccopteryx are wanting in these Bats; but in most of them there is a small membranous band, enclosing the angle formed by the tip of the fore-arm and the base of the fifth finger, and thus forming a little pouch.
The Tomb Bat (Taphozous perforatus) is one of those which presents a pouch of this description, and the male also possesses a large throat-sac, which is altogether wanting in the females. It is about three inches in length, exclusive of the tail, which is thin at the extremity; the wing-membranes extend down to within about a quarter of an inch of the ankles, and the heel-spurs are about as long as the tibia. The body is covered with short dark-brown fur, which extends over the bases of the wings, and down the interfemoral membrane as far as the point where the tail emerges from it.
This is the species originally discovered by Geoffroy in the chambers of the Pyramids, and other tombs and buildings in Egypt. It is said also to inhabit Sennaar and Senegal. It flies in the evening, passes the day in the darkest places it can find, and feeds exclusively upon insects. These habits, indeed, appear to be common to all the species of the genus.[221]
THE EGYPTIAN RHINOPOME.[222]
This Bat, described by the French traveller and naturalist Belon, about the middle of the sixteenth century, under the name of the Egyptian Bat (Chauve-Souris d’Egypte), is one of the most singular members of the order Chiroptera. It presents so curious a combination of characters that its place in the system has always been uncertain; and owing to the presence of a small nose-leaf, it has hitherto been arranged by different writers with the Phyllostomata, the Rhinolophidæ, and the Nycteridæ. Its true place, according to Mr. Dobson’s recent researches, appears to be with the Emballonuridæ, with which, and especially with the Taphozoi, it certainly agrees closely in the form of the skull and the dentition. This view of the relationships of the genus Rhinopoma seems also to have struck Cuvier, who, while placing the genus next to Nycteris, makes Taphozous immediately follow it.
The genus is characterised by having the crown of the head considerably elevated, with a deep concavity in the forehead between the eyes, as in Taphozous; the muzzle considerably elongated beyond the opening of the mouth; the nostrils of valvular structure, situated in the anterior margin of a very small, erect nose-leaf, which bears some resemblance to those of the Phyllostomes; the ears rather large, united upon the forehead (a Nycterid character), and furnished with a well-developed tragus; and the tail long and slender, and free throughout almost its whole length from the interfemoral membrane, which is exceedingly short. The upper incisors are two in number, and of very small size, inserted in intermaxillary bones which unite with the maxillaries by slender processes, a character which also occurs in Emballonura. In the lower jaw there are four incisors in a close row. The canines are strong, and followed on each side by a single pre-molar in the upper, and two in the lower jaw; and there are three true molars with W-shaped cusps on each side in both jaws: thus the dental formula is--incisors, (1–1)/4, canines, (1–1)/(1–1), pre-molars, (1–1)/(2–2), molars, (3–3)/(3–3). The index finger consists of three joints, a metacarpal bone and two phalanges, a structure which occurs in no other Insectivorous Bats.
The Egyptian Rhinopome, which is probably distributed over a considerable portion of the African continent, is a small Bat, the length of the head and body being only about two inches and a quarter. The portion of the tail free from the membrane is about the same length as the head and body, and the interfemoral membrane encloses about another half-inch. It has a nearly naked face, along the middle of which a narrow groove runs back from the base of the little nose-leaf to the deep concavity situated in the forehead between the eyes; the wing-membranes are attached to the tibia for about two-thirds of the length of the latter, and are entirely free from hair; and the small development of the membranes, coupled with the comparatively great length of the limb-bones, renders this Bat more active in walking than most of his fellows. The fur is short, and leaves a good deal of the hinder part of the back naked; and the bare skin thus exposed, as well as the base of the wings, is curiously wrinkled, a character which this species has in common with certain species of Taphozoi and Molossi.
The Egyptian Rhinopome is found commonly in Egypt, where it frequents the numerous ruins and old buildings with which that country abounds, and is particularly abundant in the dark galleries and chambers of the Pyramids.[223]
THE GREAT HARE-LIPPED BAT.[224]
In Seba’s well-known illustrated book on Natural History a peculiar species of Bat is described and figured under the name of “Vespertilio cato similis americanus.” It may be doubtful whether any of our domestic Grimalkins would be much flattered by the likeness thus briefly indicated (see figure), but there can be no doubt that the animal in question was a Bat, and as such it duly appears in the earlier editions of the “Systema Naturæ” of Linnæus. By a curious misapplication of the very sound principle of not being guided exclusively by external characters, the great Swedish naturalist was led in the last edition of his work (in which he founded the genus Noctilio) to refer the animal to the Rodents, on the ground of the apparent presence of only two incisors in each jaw.
A glance at the dentition of a Noctilio will at once show how Linnæus was misled, and at the same time that it has all the dental characters of a Bat. In the upper jaw there are four incisor teeth, the two middle ones approximated and considerably larger than the lateral ones, which are placed quite behind them, leaving a small open space between the incisors and the larger canines, behind which comes a series of four molars showing the characteristic W-shaped cusps very distinctly. In the lower jaw there are only two small notched incisors, followed immediately by the powerful canines, behind which is a series of five molars, the first very small, the second larger, but simple and pyramidal, and the remainder with distinct cusps and ridges.
The ears in the Bats of this genus are rather large and furnished with a small tragus, the outer margin of which is notched. The outer margin of the ear forms a rounded lobe upon the cheek, and is then continued to the angle of the mouth. The upper lip is widely cleft, forming a broad margined fissure running up to the nostrils, which are surrounded by borders raised to such an extent as to give them almost a tubular appearance; and the lower lip, which is also thickened, bears several curious folds of skin; the whole in combination giving a most singular and forbidding expression to the little creature. The wing-membranes descend but little below the knee, but the interfemoral membrane is ample, stretched by very long spurs, and traversed in its basal part by the short tail, the tip of which projects from its upper surface like a little knob.
The great Hare-lipped Bat (Noctilio leporinus), which is distributed over the whole of tropical and sub-tropical South America, from the West Indies in the north to Paraguay and Chili in the south, is about three inches and three-quarters in length without the tail, and has an expanse of wing of about twenty-one inches. The general colour of the fur on the back is greyish-brown or reddish-brown, but in many specimens a yellowish-white streak runs from the nape down the middle of the back to the root of the tail. The throat, neck, and belly are reddish-yellow, the ears, membranes, and other naked parts blackish-brown. The interfemoral membrane extends about two inches beyond the tail, which is three-quarters of an inch long, and the heel-spurs are more than an inch in length.
This Bat lives in large parties in hollow trees, caverns, the roofs of buildings, and even among the dense foliage of trees, but generally in the immediate vicinity of water. In the twilight they are seen in great numbers flying, almost in the same way as the Swallows in Europe, in great flocks over the surface of the water, close to which they skim with a very rapid flight in pursuit of the insects which constitute their food. The voice is described by Prince Maximilian of Neuwied as a hissing sound. According to an observation made by Mr. Louis Fraser in Ecuador, the object of the Noctilio in haunting the waters is not so peaceful as that of most bats, which, so far as we know, resort to the lakes and rivers only to drink. Mr. Fraser describes it as flying along the banks of rivers, and from time to time dashing down upon the surface of the water, where it captures small Crustaceans as they swim up the stream. He adds that the Bats have a fishy odour, and possibly they do not strictly confine themselves to invertebrate prey.[225]
CESTONI’S BAT.[226]
We come now to a series of Bats (the Molossi of Professor Peters and Mr. Dobson) which we shall treat here as belonging to three genera, the classification and nomenclature of which are attended with considerable difficulty, partly owing to the variability of characters on which we are accustomed to rely in the definition of generic groups, and partly to the confusion which has arisen in the use of the generic names employed especially by the older writers. They are all stoutly and rather clumsily built Bats, with short, thick muzzles, a character which has obtained for some of them the name of Bulldog Bats; the tail is thick, and projects beyond the margin of the interfemoral membrane, the hinder limbs are short and stout, and the fibula or second bone in the shank is well developed, often nearly as large as the tibia.
In the genus Nyctinomus, as we shall here restrict it, the ears are large, and generally united upon the forehead or on the muzzle in front of the eyes, either directly or by a fold of skin, and furnished with a distinct tragus, and the upper lip is more or less distinctly folded or wrinkled. The intermaxillary bones are generally separated by a cleft; and in all the species they bear two incisor teeth, which are separated by a space from each other and from the canines, whilst the lower jaw has six incisors in young animals, and usually only four in the adults. The canines are strong, and followed in the upper jaw by either four or five teeth, the number of premolars being either one or two. In the lower jaw there are always two premolars, and three true molars. The first and fifth toes are much thicker than the rest. The species of this genus occur in the warmer parts of both hemispheres.
Cestoni’s Bat, originally discovered at Pisa, is the only species of the group that occurs in Europe, and forms the type of the genus Dinops of Professor Savi, now regarded as a sub-genus of Nyctinomus. It is one of the species with five molars in each jaw, and six incisors permanently in the lower jaw; and the tail extends for fully half its length beyond the interfemoral membrane, which is small, and stretched by long curved heel-spurs. A small membranous band crosses the shank, uniting the wing with the interfemoral membrane. The general colour of the fur is a mouse-grey, paler below; on the backs of the toes there are some long white hairs. The wings in this and the other species of Nyctinomus are long but narrow; the second finger, which runs to the tip of the wing, being very long, so long indeed that its metacarpal bone alone exceeds the fourth or hindmost finger in length. The inner toe also is rather larger than the rest, and somewhat separated from them, without, however, taking on the form and function of an opposable thumb. The head and body in this Bat are about three inches and a quarter long, and the tail rather more than two inches, of which about an inch is within the interfemoral membrane. It has a very wide distribution, being found in the South of Europe and throughout Northern Africa, and occurring also at Amoy, in China, where Mr. Swinhoe obtained specimens of it. He describes the interfemoral membrane as fitting loosely on the tail like a glove, so that it can slip up and down at the will of the animal. It flies high in the air, where it can be readily distinguished by the narrowness of its wings. A specimen that Mr. Swinhoe kept for some time alive would slip the interfemoral membrane up and down when irritated, and had the further disagreeable habit under such circumstances of protruding its eyes until they seemed ready to fall out of their sockets. In Egypt Cestoni’s Bat is one of those that frequent the Pyramids and other old buildings, which must make that country a perfect paradise for Bats.[227]
THE PALE CHESTNUT MASTIFF BAT.[228]
This widely-distributed species belongs to the typical sub-genus Nyctinomus, in which the characters of the genus are most clearly manifested, the upper lip especially being very strongly folded. Its total length is about four inches, an inch and a half of which is made up by the tail, about half of which is enclosed by the interfemoral membrane. The body is covered with a thick, short, soft fur, which scarcely encroaches upon the membranes, and is composed of hairs of a fawn colour at the tips, with the basal portion whitish or light ash colour; the fawn colour is paler on the lower surface of the body. The ears are of considerable size, rounded, closely approaching each other, but not joining on the top of the head, and furnished with a small tragus. The inner margin of the ear bears a row of five or six minute warts.
This species is found commonly in South America and the West Indies, and also extends northwards into the United States, at least as far as Charleston, in South Carolina. Mr. Osburn gives an excellent account of its habits, as observed by him in Jamaica, where this Bat is often very abundant in the houses. He says, “They generally appear from half-past five to six o’clock, directly after sundown, and occasionally appear up to ten o’clock, but not in such numbers. They again make their appearance in my bedroom before dawn. The beating of their wings, with the occasional squeaking call, is quite familiar to me as the first sound of morning.” Its cry resembles the sound “click-click.” In the shingled roof of the house at Rowington Park, Vere, Jamaica, these Bats were exceedingly abundant, passing the day clinging together in clusters, notwithstanding the heat experienced immediately beneath the shingles. Mr. Osburn says that he “counted fourteen little heads in a mass about the size of a turnip.” Under these circumstances, however, they are not all asleep. “Now and then,” says Mr. Osburn, “a wing is stretched in drowsy enjoyment; and the luxury King James thought too great for subjects, and ought to be reserved for kings, is largely indulged in by Bats. First one and then another wakes up, and withdrawing one leg, and leaving itself suspended by the other alone, adroitly uses the foot at liberty as a comb, with a rapid, effective movement dressing the hair of the under part and head--an action far from ungraceful. The foot is then cleaned quickly with the teeth or tongue, and restored to its first use,” of suspending the animal. A little after sundown, according to Mr. Osburn, the roof is alive with movement, betrayed by squeaks and a scuffling shuffle over the boards, and the Bats scramble eagerly up the shingles, and escape through any opening they may find, shooting off with great rapidity in search of their insect prey. In March they made their exit about half-past six o’clock in the evening, returning to their dwelling-place about eight or nine o’clock. “It is then,” says Mr. Osburn, “they are so particularly annoying to the inhabitants of even the most carefully kept Jamaica houses. The great majority return to the roof; but one or two vigorous little fellows come into the room, and flap about in the most unmeaning way. Nothing is more remarkable than the agility with which a dozen, in the early part of the evening, skimmed and glided by every article of furniture. But now they bang themselves against the ceiling and walls, drop on the table, get up again, when the Cat, by jumping, catches them a pat, and they fall on the floor, not much hurt, to judge by their liveliness, for Grimalkin, having performed the feat, sits down, her paws tucked under, and gravely watches the hurry of the alarmed Bat shuffling over the floor. They disturb the harmony of the evening by becoming the occupants of, and making an escapade beneath, a gentleman’s coat collar, or a great sensation by getting hopelessly entangled in a lady’s hair, and bite more furiously than effectively during the process of release.” These restless little fellows, which must at least add considerably to the liveliness of an evening réunion in those parts of Jamaica where they abound, remain very active in their quarters all night, and start out in search of their breakfast so early that they return home again by five or six o’clock. They then seem to amuse themselves, before retiring to their own repose, by breaking the slumbers of the people whose evening hours they have enlivened as above described, by flying about the bedrooms with a rushing sound and many squeaks. The species is exceedingly common in Jamaica, and seems always to inhabit houses. Mr. Gosse (“Naturalist in Jamaica,” p. 159) also describes the habits of this Bat, which he calls the Chestnut Mastiff Bat.[229]
THE SMOKY MASTIFF BAT.[230]
In this abundant American Bat the fur is generally of a smoky-brown colour, with the bases of the hairs whitish; on the lower surface some of the hairs are entirely white, and the rest brown, with the base and apex whitish. The length of the head and body is from three and a half to four and a half inches, and that of the tail about two inches, nearly half of which projects beyond the membrane. The heel-spurs are very long. In this and the other species of Molossus, the intermaxillary bones are united, and the upper incisors close together in front.[231]
The Smoky Mastiff Bat is a well-known South American species, and extends also into the West Indian islands. In Jamaica it was observed and described by Mr. Gosse under the name of the Monk Bat, in allusion to the fact that he found the species living in large communities, but always of one sex. Mr. Osburn also observed it in the same island, and has given a long account of its habits. In the house in which he was living at Shettlewood, these Bats swarmed in the roof, and during the breeding-season, his bedroom, situated immediately below, was rendered so offensive by their peculiar odour, that he was compelled to have every window left wide open at night. The Bats passed out from the roof under the eaves, but not unfrequently small parties of them would come in through the windows and take a short flight round the room. A man sent up into the roof brought down four or five quarts of the Bats, all of which proved to be males. These Bats also live in holes in dead stumps of cocoa-nut trees, and Mr. Osburn describes as follows the results of felling one of the stumps thus occupied. He says:--“It was broken into fragments by the fall, and among them a perfect hecatomb of these little Bats, scattered into two distinct heaps, corresponding to a high and a lower storey in the tree. There must have been at least 150 or 200 altogether. The heap which occupied the upper hole were exclusively males; those in the lower, females, in large proportion, though there seemed a male here and there among them.” Mr. Osburn’s observations thus strikingly confirm those of Mr. Gosse as to the curious habit of segregation on the part of the males of this species, which induced the latter gentleman to give it the name of the Monk Bat. The holes occupied by the Bats contained a great quantity of dust looking like coarse snuff, which proved to consist entirely of fragments of the hard parts of insects. Mr. Gosse appears not to have observed this Bat in houses, but he describes it as living in great numbers together in the hollows of decayed thatch-palms. He had brought to him a large basket containing a number of the Bats obtained from such a tree, and says that, on being uncovered, it “displayed a pretty scene of dusky life. The ‘pie’ of our infant days, that contained ‘four-and-twenty blackbirds’ all ready to sing, was nothing to it. Fifty Bats, all alive and kicking, were huddled into the narrow space; an arrangement which, considering their natural propensities, was probably not very disagreeable to them. I examined forty-three, a few escaping from the crowd, and if I was surprised before at the extent of their gregarious habits, I was still more surprised to find that of this number every one was of the male sex, as had been the one formerly examined.... As they huddled and crawled over each other they emitted quivering squeaks. They all displayed the extraordinary activity mentioned above, preferring to run rather than fly, though a few took to wing. In climbing, to suspend themselves, they used the thumbs or the hind-feet indiscriminately. In running along the floor, an action which they performed very swiftly, they rested on the wrists, elevating the fore-parts of the body considerably.”
THE COLLARED BAT.[232]
The Mastiff Bats certainly cannot boast of any great attractiveness in their aspect, but they must yield the palm of ugliness to a curious species described by Dr. Horsfield. It is a clumsy, heavy-looking animal, of considerable size for a Bat, measuring more than five inches in length from the tip of the nose to the root of the tail. Its body is entirely covered with a thick black skin, which is absolutely naked on the back, and has only a few short hairs upon the sides of the body, the interfemoral membrane, and the lower surface. The face and lips also have a few fine long hairs, and a curious collar of brown hairs runs round the neck. To add to the charms of the creature, the skin is thrown into thick folds in various parts of the body; the legs are thick, and terminated by clumsy feet, in which the first toe is very large, bristling with long hairs on the outside, and widely separated from the others, so as to acquire very much the character of a posterior thumb; the interfemoral membrane is short, forming a mere band between the legs, from which the tail, which is about half as long as the body, and very thick, projects for about two-thirds of its length. The head is long; the muzzle, which is truncated, projects considerably beyond the lower jaw; the ears are quite separate, triangular, with the tips rounded; the tragus is very small; the wings are long, and rather narrow, and their membrane extends down to about the middle of the shank, but springs from such a level on the sides of the body, that a deep cavity is formed on each side under the armpit, which is converted into a sort of pouch by an extension of the skin of the sides to the lower surface of the upper arm and thigh. In the pouches thus formed, and close to the armpits, the nipples are situated. There are two incisor teeth in each jaw, the upper ones strong, and implanted in well-developed and united intermaxillary bones. The upper jaw has one, and the lower jaw two premolars on each side, and there are three true molars on each side in both jaws.
This hideous Bat was discovered in the peninsula of Malacca, and has since been found in Java, Sumatra, and Borneo. It does not appear to be abundant in its native countries, and its apparent rarity is doubtless increased by its selecting for its residence the wildest and most solitary districts in the heart of the great forests. During the day it usually retreats to the hollow trunks of trees, but sometimes takes its repose in holes in the ground or in clefts of the rocks, coming out soon after sundown, when it is seen flying heavily about the borders of the woods, or even high up above the forest in the plains.
Another curious but by no means agreeable peculiarity of this species remains to be noticed. Across the base of the neck, immediately in front of the breast, there is a great pouch, formed apparently by a fold of the skin, which receives an oily secretion from a large gland, regarded by Professor Temminck as perhaps analogous to the thyroid. In the male this gland is very broad, and divided into two lobes, and the fluid secreted by it passes into the pouch by a great number of small pores. In the female the apparatus is smaller, but more complicated; the gland is composed of two small lobes, but between these there is a membranous pouch or reservoir, in which the oily fluid seems to become concentrated, forming a brown, granular, fatty matter, which passes into the great throat-pouch through a single large opening. This secretion possesses an odour so strong as to be still perceptible after the animals have been preserved in spirits for several years; and Dr. Salomon Müller states that his artist, M. van Oort, when engaged in making a drawing from a living specimen, was affected with a headache and nausea so violent that he had much difficulty in completing his task. It appears that the fetid fluid gets diffused over the hairs bordering the throat-pouch, and thus readily passes off into the air, and spreads to a long distance round the places inhabited by the Bats, and may thus serve, as Professor Temminck suggests, to enable these creatures to find each other in the dark retreats which they frequent. This would apply to other species which diffuse a peculiar odour, although none of them seem to possess so powerful an odoriferous secretion as the Collared Bat.
THE NEW ZEALAND SHORT-TAILED BAT.[233]
We have already noticed the occurrence in New Zealand of a species of Bat nearly allied to the common Bats of Europe, although differing from them in certain characters which have led to the formation of a distinct genus for it. The present species, the second known Bat of New Zealand, is a far more remarkable animal; in fact, its characters are so singular that it forms not only a distinct genus, but a peculiar sub-division of the family to which it belongs.
The Short-tailed Bat of New Zealand, which appears to be not of very common occurrence there, is a small Bat, not exceeding two inches and a half in length of head and body; the body is short and broad; the muzzle is greatly produced beyond the opening of the mouth, and terminates in a sort of projecting snout, which carries the nostrils towards the sides of its tip; the ears are quite separate, simple, ovate, and slightly pointed at the tips, and furnished with a long, narrow, and pointed tragus; the wings are rather short and broad, and the middle finger consists of four joints, having three true phalanges; the wing-membranes extend down to the end of the shank; a narrow band of the membrane running from the wrist down the arm, and bordering the side of the body and the leg, the antebrachial or shoulder membrane and the basal part of the interfemoral membrane are thick and leathery, and marked with numerous deep wrinkles on the upper surface. The tail is short, and only a very small portion of it is enclosed in the interfemoral membrane. The dentition is exceedingly peculiar. There are two upper incisors, which are nearly of the same shape as the canines; the lower jaw also has two incisors, but these are small, three-lobed at the tip, and placed in front of the canines, which are of large size, and nearly in contact at the base. There are two premolars and three true molars on each side in both jaws.
The fur is short, crisp, and thick, and extends forward on the head towards the nose, where it is bounded in front by a frill of stiff, upright hairs. On the upper parts of the body the fur is dusky at the base and tipped with a shining greyish-brown, with a slight olive tinge. On the lower surface the hairs are brown at the base, with greyish-brown tips. The membranes are dark-brown, with the wrinkled, leathery portion paler, and of a yellowish tinge. Of the habits of this species nothing has been recorded.
In many respects the New Zealand Short-tailed Bat is exceedingly interesting to the zoologist. In its structure it presents striking resemblances to species belonging to several groups, whilst its own personal peculiarities are very remarkable. These are noticed by Mr. Dobson, from whose valuable writings we have so often had occasion to quote, in a short paper read before the Zoological Society in 1876. He finds that the peculiar leathery and wrinkled portions of the membranes are so arranged that when the wings are folded--which they are in a very complicated manner, and so as to pack away into the smallest possible space--each wing is “tucked in beneath the thickened portion of the wing-membrane margining the fore-arm and side of the body, which sheathes and completely conceals the whole wing. The posterior half of the interfemoral membrane, from the point where the tail perforates it, is rolled upwards and forwards beneath the leathery anterior half.” In this way the more membranous parts of the wings are protected, as Mr. Dobson remarks, precisely in the same way that the delicate wings of the Beetles and Bugs are sheltered in repose beneath the hardened elytra. “With the wings and interfemoral membranes thus encased,” he adds, “this species is the most quadrupedal of Bats;” and the structure of the limbs indicates that all these arrangements really tend to adapt this animal for progression on all-fours. The thumb is long, and armed with a large, sharp claw, which is remarkable among Bats for having a small sharp tooth near the base, in its concave side, a structure which, from the analogy of a species of Chameleon in which the same thing occurs, is regarded by Mr. Dobson as greatly increasing the clinging power of the animal. The hind limbs are short and stout, and the feet remarkably large, and their whole lower surface, including that of the toes, is covered with a soft, loose, deeply-wrinkled skin, that of each toe showing a strong central groove with short grooves at right angles to it, very much after the pattern seen in some Geckos or Wall Lizards. This loose, wrinkled skin is also continued along the flattened lower surface of the ankle and leg. “All these peculiarities of structure,” says Mr. Dobson, “must accompany some corresponding peculiarities in the habits of this species.... I have no doubt that the denticle at the base of the claw in Mystacina tuberculata compensates that species exceptionally for the imperfect condition of the fore-limbs as organs of prehension; and this, taken into consideration with the peculiar manner in which the wings are protected from injury when not employed in flying, and with the manifestly adhesive nature of the sole of the foot and inferior surface of the legs, leads me to believe that this species hunts for its insect food, not only in the air, but also on the branches and leaves of trees, among which its peculiarities of structure most probably enable it to walk about with security and ease.” This and the Brown Pig Bat (Thyroptera tricolor), already described (p. 310), may be regarded as more especially adapted for climbing than any other members of the order Chiroptera.
VI. FAMILY VI.--PHYLLOSTOMIDÆ, OR VAMPIRES
Distinguishing Marks of the Phyllostomidæ--Location--Diet--Blood-sucking Propensities--Exaggerations of the Older Writers--Testimony of Azara--Darwin’s Evidence--Bat-bites--The Witness of Bates, Wallace, Fraser, Prince Maximilian--Conclusion of the Whole Matter--The Desmodonts and Javelin Bat--The Tongue in the Genus Phyllostoma--BLAINVILLE’S BAT--Extraordinary Development of Face and Head--OWL-FACED BAT--JAVELIN BAT--Allied Species--VAMPIRE BAT--Mr. Bates’ Testimony to its Inoffensiveness, and Description of its Habits--NEUWIED’S LARGE-LEAFED BAT--GREAT-EARED LEAF BAT--SORICINE BAT--REDMAN’S BAT--SEZEKORN’S LEAF BAT--SPECTACLED STENODERM--JAMAICAN STENODERM--DESMODUS--Dentition--Blood-sucking Propensities--The Bites--Stomach of Desmodus, Frugivorous and Insectivorous Bats--Classification--Concluding Remarks.
We have already seen that the first group of ordinary Bats includes two sets of species, one characterised generally by the possession of dermal complications of the muzzle, the other by the absence of any such arrangements; and in like manner the second alliance has also its simple-nosed and leaf-nosed forms. Of course, the presence or absence of the nose-leaf can only be regarded as a secondary character; and we have had occasion to show that its mere existence is not sufficient to overrule other important structural peculiarities (as in the genera Nyctophilus among the Vespertilionidæ and Rhinopoma among the Emballonuridæ), but in conjunction with such characters it must be regarded as of great value, especially since its development would seem to be associated, as already pointed out, with that wonderful acuteness of the tactile sense which seems to guide the Bats in their nocturnal wanderings.
In the Phyllostomidæ, or Leaf-nosed Emballonurine Bats, this is strikingly the case, and the family may be regarded as an especially well-marked group, distinguished from all other Bats (except the genus Mystacina) by the presence of three distinct phalanges in the middle finger. Of these joints the first is short, and bent up in repose along the upper surface of the metacarpal bone, in the manner characteristic of the Bats of this division. The nasal appendages are sometimes rudimentary, but generally exhibit a structure more or less resembling that characteristic of the Horseshoe Bats, the nostrils opening in the fissure between the front-piece, or horseshoe, and true nose-leaf; and the chin is furnished with warts, or erect ridges of skin, reminding us of the same parts in the genus Noctilio, which certainly forms a sort of transition between the Emballonuridæ and Phyllostomidæ. Another character which seems at once to distinguish these Leaf-nosed Bats from those of the first division is the complete development of the intermaxillary bones, which in the Rhinolophidæ and Nycteridæ are rudimentary, or represented by mere cartilages. The dentition varies very considerably in this family, but in all the species the canines are large and acute, and the molar teeth show either the usual W-shaped cusps, or a sharp, cutting edge, like that found in some carnivorous mammals.
The Phyllostomidæ are entirely confined to the warmer parts of America. Several of them are of considerable size. The food of some consists of insects; others find their nourishment in fruits; and a good many appear to have the habit of sucking the blood of other animals--an evil practice which has been erroneously ascribed to the species generally, causing them, under the name of Vampires, to be regarded as most formidable animals. As many of the accounts of the blood-sucking propensities of these Bats give no definite clue to the species referred to, and the number of species which seek this form of nourishment, habitually or occasionally, is very doubtful, it may be as well to give a general statement on the subject in this place.
The earliest accounts of the natural history of America contain references to these animals, with a probably somewhat exaggerated statement of the fatal effects of their attacks upon men and animals. Peter Martyr declares that the Bats suck the blood of men and animals while they are asleep, exhausting them to such an extent as to cause death. Piso, Father Jumilla, Don Antonio de Ulloa and many other writers, express themselves in similar terms, and generally agree in representing the consequences of the bites as very serious.
La Condamine, who travelled in South America in the early part of the last century, confirms the above statements as to these Bats, which, he says, attack man, and even destroy animals. He ascertained that they suck the blood of Horses and Mules, and stated that they had in some places destroyed the cattle introduced by the missionaries.
Azara, in his natural history of the quadrupeds of Paraguay, describes the blood-sucking habits of a species which has been referred to the genus Stenoderma. He says:--“I have seen a great number; they were all constantly identical among themselves, but differ from all other Bats in that, when put on the ground, they run nearly as fast as a Rat, and they like to suck blood. Sometimes they bite the combs and wattles of sleeping fowls, and suck their blood, in consequence of which the fowls die, because the wounds mortify. They also bite Horses, Mules, Asses, and horned cattle, usually on the rump, the shoulders, or the neck, because in these parts they find it convenient to cling to the mane or the tail. Lastly, man is not free from their attacks; and upon this point I can give certain testimony, seeing that they have bitten me four times in the tips of my great toes, when I was sleeping in the open country in huts. The wounds they made without my feeling them were circular or elliptical, from a line to a line and a half in diameter, but so shallow that they did not entirely penetrate my skin, and it could be seen that they were made by removing a small piece, and not by piercing, as might be supposed. Besides the blood which they sucked, I reckon that what flowed away might be half an ounce when I lost most by their attack; but as the effusion in the case of horses and cattle is about three ounces, and the skin of these animals is very thick, it is to be supposed that the wounds are larger and deeper. This blood comes neither from the veins nor from the arteries, seeing that the wound does not extend to them, but from the capillary vessels of the skin, from which the Bats, no doubt, draw it by sucking and licking. Although my wounds were painful for several days, they were of so little consequence that I did not apply any remedy to them.”
These statements of Azara’s reduce the affair to rather more moderate dimensions than would appear to belong to them from the exaggerated statements of the older writers, which can only be accepted with some allowance for the love of the marvellous inherent in those who have strange things to tell of new countries. But even these less extravagant accounts of the Vampires of South America were regarded in Europe with some feeling of scepticism; and Mr. Darwin appears to have been one of the first reliable naturalists to observe the act of blood-sucking on the part of a Bat of this family, belonging to the genus Desmodus. He says (“Journal,” p. 25):--
“The Vampire Bat is often the cause of much trouble, by biting the Horses on their withers. The injury is generally not so much owing to the loss of blood, as to the inflammation which the pressure of the saddle afterwards produces. The whole circumstance has lately been doubted in England; I was therefore fortunate in being present when one was actually caught on a Horse’s back. We were bivouacking late one evening near Coquimbo, in Chili, when my servant, noticing that one of the Horses was very restive, went to see what was the matter, and fancying he could distinguish something, suddenly put his hand on the beast’s withers, and secured the Vampire. In the morning, the spot where the bite had been inflicted was easily distinguished, from being slightly swollen and bloody. The third day afterwards we rode the Horse without any ill effects.”
Tschudi, who travelled in Peru, and wrote on the natural history of that country, gives an account of his experience in the matter of Bat-bites. According to him, the blood which the Vampires draw from the wounds inflicted by them on cattle and horses is not more than an ounce or two, but the wound continues to bleed freely for some time; and it is not uncommon in the morning to find the animals attacked in a deplorable state, and bathed in their own blood. He mentions the case of an Indian who went to sleep when intoxicated, and was bitten in the face by a Vampire. The wound, which was small, and apparently of little consequence, was followed by an inflammation and swelling so great that the man’s features became quite unrecognisable. In all probability, the condition of his blood after his debauch may have had a good deal to do with the severity of the after-effects of the wound.
Mr. Bates, who during his travels on the Amazon was once wounded in the hip, probably by a Bat, which he describes as a small dark-grey Phyllostome streaked with white down the back, states that it is only a few persons who are subject to be so attacked. His friend Mr. Wallace seems to have had a larger experience in this respect. He ascribes the mischievous propensity to the great Javelin Bat (Phyllostoma hastatum), of which he says:--
“This is a common Bat on the Amazon, and is, I believe, the one which does much injury to horses and cattle, by sucking their blood; it also attacks men, when it has opportunity. The species of blood-sucking Bats seem to be numerous in the interior. They do not inhabit houses, like many of the frugivorous Bats, but enter at dusk through any aperture they may find. They generally attack the tip of the toe, or sometimes any other part of the body that may be exposed. I have myself been twice bitten, once on the toe, and the other time on the tip of the nose; in neither case did I feel anything, but awoke after the operation was completed. In what way they effect it is still quite unknown. The wound is a small round hole, the bleeding of which it is very difficult to stop. It can hardly be a bite, as that would wake the sleeper; it seems most probable that it is either a succession of gentle scratches with the sharp edge of the teeth, gradually wearing away the skin, or a triturating with the point of the tongue, till the same effect is produced. My brother was frequently bitten by them, and his opinion was that the Bat applied one of its long canine teeth to the part, and then flew round and round on that as a centre, till the tooth, acting as an awl, bored a small hole, the wings of the Bat serving, at the same time, to fan the patient into a deeper slumber. He several times awoke while the Bat was at work, and though of course the creature immediately flew away, it was his impression that the operation was conducted in the manner above described. Many persons are particularly annoyed by Bats, while others are free from their attacks. An old mulatto at Guia, on the Upper Rio Negro, was bitten almost every night, and though there were frequently half a dozen other persons in the room, he would be the party favoured by their attentions. Once he came to us with a doleful countenance, telling us he thought the Bats meant to eat him up quite, for having covered up his hands and feet in a blanket, they had descended beneath his hammock of open network, and attacking the most prominent part of his person, had bitten him through a hole in his trousers! We could not help laughing at the catastrophe, but to him it was no laughing matter.
“Senhor Brãndão, of Manaquery, informed me that he had once an Indian girl in his house, who was much subject to the attacks of the Bats. She was at length so much weakened by the loss of blood that fears were entertained of her life, if they continued their attacks, and it was found necessary to send her to a distance, where these bloodthirsty animals did not abound.
“The wound made by them is very difficult to heal, especially in its usual locality--the tip of the great toe--as it generally renders a shoe unbearable for a day or two, and forces me to the conclusion that, after the first time, for the curiosity of the thing, to be bitten by a Bat is very disagreeable. They will, however, very rarely enter a lighted room, and for this reason the practice of burning a lamp all night is almost universal.”
In the island of Muciana, situated in the mouth of the Amazon River, Mr. Wallace had an opportunity of observing the mischief done by these blood-sucking Bats on a large scale. The island is used as a grazing-ground, but some of the horses and cattle on it, says Mr. Wallace, were “miserable-looking objects, from wounds inflicted by the Bats, which cause them to lose much blood, and sometimes, by successive attacks, kill them. Senhor Leonardo informed us that they particularly abounded in some parts of the island, and that he often has Bat-hunts, when several thousands are killed.” Mr. Wallace describes the criminal in this locality as a large coffee-brown Bat, probably the Phyllostoma, hastatum. He adds that they “live in holes of trees, where they are killed in considerable numbers, Senhor Leonardo informing me that they had destroyed about seven thousand during the last six months. Many hundreds of cattle are said to have been killed by them in a few years.”
Mr. Louis Fraser, when collecting at Gualaguzia, in Ecuador, obtained a specimen of the Javelin Bat, and was told by the Indian who brought it to him that this species attacks the Mules.
Prince Maximilian of Neuwied also lays the crime of blood-sucking at the door of the Javelin Bat. He says:--“In its stomach I found remains of different kinds of insects, but never any traces of blood that had been swallowed; nevertheless, it is certain that this and many other species of Phyllostomes suck the blood of animals. I have never surprised such a Bat at the moment of sucking, but have observed in the moonshine and twilight how these large animals fluttered, with strongly rustling wings, about our grazing beasts of burthen, which bore their vicinity quietly, but on the following morning were covered with blood, from the shoulders down to the hoofs. On the Rio das Contas we found the cattle quite exhausted with the loss of blood.” The same author adds:--“As I have never found blood in the stomachs of the Phyllostomes, this nutriment can only be partaken of by them rarely, and for this reason I do not venture to decide whether some, or all, or what species of them are fond of this food; but with regard to the largest species here described, it needs no further confirmation, and I believe that of all the Phyllostomes described by me, it is nearly the only one that sucks blood.”
It will be seen from the foregoing statements that there is some uncertainty as to the precise species which may justly be charged with the crime of blood-sucking. The habit has been ascribed to various species, some of which are now known to feed upon fruits, whilst others find their nourishment in the abundant insect population of tropical America; and in the opinion of many zoologists of the present day, the sole criminals are the species of the genus Desmodus, a small aberrant group, specially distinguished from all the rest by the structure of their teeth and stomach. Mr. Tomes, in commenting on Mr. Fraser’s statement, suggests that the blood-sucking was performed by the Desmodonts, which accompanied the Javelin Bat in Mr. Fraser’s collection, and the guilt transferred to the larger and more striking species; and the same explanation may apply to the accounts given by Mr. Wallace and Prince Maximilian, both of whom apparently charge the Javelin Bat with sanguinivorous proclivities solely upon circumstantial evidence. If this be the case, Phyllostoma hastatum must be regarded as a very unfortunate animal. Professor Reinhardt agrees with Mr. Tomes in considering the Desmodonts (Desmodus and Diphylla) the only blood-sucking Bats, and they appear to be the only forms that have been actually taken in the fact.
At the same time we are perhaps hardly justified in passing a verdict of not guilty in the case of some of the other species, for certain observers record the finding of blood in the stomach, and by others the structure of the mouth is looked upon as furnishing circumstantial evidence of sanguinary propensities. Thus Professor Bell says that the tongue in the genus Phyllostoma has a number of wart-like elevations, so arranged as to form a complete circular suctorial disc when they are brought into contact at their sides, which is effected by a set of muscular fibres having a tendon attached to each of the warts. By means of this curious sucker, he adds, these Bats are enabled to suck the blood of animals and the juice of succulent fruits. According to other writers the papillæ which are borne by the lips (see figure), and which seem to have some analogy with the wrinkles occurring on the lips of the Mastiff Bats, serve this same office; and Prince Maximilian especially describes the mode in which the lips in the Javelin Bat may be converted into a sucking-canal. It is to be observed, however, that these papillae are greatly developed in species which are now known to derive the whole or the greater part of their nourishment from fruits.
BLAINVILLE’S BAT.[234]
A most grotesque species of Bat, the position of which has been a subject of some discussion, as it seems to be almost equally related to the Emballonuridæ on the one hand, and to the Phyllostomidæ on the other, was described many years ago (in 1821) by the late Dr. Leach under the name of Mormops Blainvillii. As regards the development of the cutaneous system about the face, this species is without exception the most extraordinary species of the whole order (see figure). The skull itself is of curious structure, the cranial portion, or that containing the brain, being so much elevated, that its height is nearly equal to the whole length of the skull, and its front wall descends in such a manner as to form nearly a right angle with the bones of the face (see figure). The superficial structures belonging to the face and head are so complicated as almost to defy description, and so grotesque that one might recommend their study to the inventors of demon-masks for pantomimic purposes. The ears are of considerable size, and have their margins notched in several places; they sweep round on the cheek, to terminate at a short distance from the angle of the mouth, and have their inner margins joined by a fold of membrane. The tragus is a thick, more or less lobulated organ. The nostrils are round apertures in the extremity of the snout, their margins are raised and naked, and produced above into small lobes. Between the nostrils there is a perpendicular ridge, and above this a small round papilla on each side of which there is an irregular kidney-shaped elevation. Behind these parts comes a large fold of skin, deeply notched in the middle above, which joins on each side with the middle of the membrane uniting the ears, and probably represents the hinder nose-leaf in some other Bats. The lower lip consists of two leaves, the upper of which forms in the chin a large shield-shaped, warty plate, beneath which the lower leaf and the skin of the throat form a complicated series of lobes.
The teeth in this Bat consist of four incisors and a pair of strong canines in each jaw, two pre-molars in the upper and three in the lower jaw, and three molars, with more or less distinct W-shaped cusps on each side in both jaws (dental formula--incisors, 4/4 canines, (1–1)/(1–1), pre-molars, (2–3)/(3–3), molars, (3–3)/(3–3)). The wings are well developed, long, and broad, and the membranes descend to the ankles (see figure); the first phalanx of the middle finger is very short. The interfemoral membrane is ample, and stretched by two very long heel-spurs; it is perforated before the middle for the passage of the tail, about one-third of which projects on the upper surface of the membrane.
The length of the head and body in this species is about two inches and two-thirds, and that of the tail from one inch to one inch and one-sixth, according to the sex, being longer in the male. The fur of the upper side is of a rich umber-brown, and that of the lower surface brownish-grey, the difference being caused by the brown tips of the hairs above, which are wanting on those of the under side. The hairs on the inner margin of the ear are shiny brown. The membranes are dark-brown. This species is an inhabitant of South America and of the West Indies, but it does not seem to be very abundant. Nothing has been recorded as to its habits, but it is probably a strictly nocturnal Bat.
Blainville’s Bat is the type of a small group of Phyllostomidæ, which, as already indicated, form a sort of transition towards the more normal Emballonuridæ, the line of relationship probably passing through the Noctiliones. This group (Mormopes, Peters; Lobostominæ, Dobson) is characterised by its terminal nostrils, and the cutaneous folds or ridges on the chin.
THE OWL-FACED BAT.[235]
This is another species of the Mormops group, but very much less remarkable in its characters. It has pointed ears, with an elongated tragus. The hinder nasal appendage, which is so large in Blainville’s Bat, here forms merely a sort of transverse pad across the middle of the muzzle, and the nostrils are pierced in the middle of the upper part of a naked piece, which rises directly from the upper lip. The lower lip is warty, but the warty portion gradually passes into the other part of the lip, and below it there is a thin fold of skin. The skull is considerably longer than high; and while the teeth are present in the same number as in Mormops, the second premolar in the lower jaw is small, and removed inwards from the line of the series of teeth.
The Owl-faced Bat is a small species, the head and body measuring only two inches. The tail is an inch long, and about a fifth of it projects from the upper surface of the interfemoral membrane, which is expanded by a pair of very long spurs. The expanse of wing is nearly twelve inches, which is very great for so small a Bat. The body is covered with a short, soft fur, of a brownish-grey colour above, and pale-grey beneath; the membranes are black.
The Owl-faced Bat was originally obtained from Cuba, but it has since been captured in St. Domingo and Jamaica, and may probably occur elsewhere in the West Indies, or on the continental part of Central America. Mr. Gosse, when in Jamaica, captured a specimen which flew in at an open window, but did not allow itself to be taken until after a very tedious pursuit, in which it manifested great agility on the wing. He says that “in captivity it uttered once or twice, very slightly, the peculiar short sound resembling the clicking of some delicate piece of machinery, which every one who is familiar with living Bats will remember as common to most of these animals. It was very active, leaping up to flight from the table, and expanding the wings in a moment, though confined within a candle-shade. It bit fiercely at the hand that held it, but could not draw blood from the fingers. It usually carried the apical half of the interfemoral bent upward at the point where it ceases to embrace the tail, so that the tail seems to extend beyond the membrane. It is thus held by the calcanea, the tips of which, curving downward, carry down again the tip of the membrane, puckered into minute plicæ.”
Another species of this genus, Chilonycteris Parnellii, inhabits Cuba and Jamaica, and two others, C. personata and C. rubiginosa, occur in Brazil, and extend thence to Central America.
Another allied form is Davy’s Bat (Pteronotus Davyii), which is remarkable for having the wings attached along the course of the spine, as in the Pteropid genera Cephalotes and Notopteris (see pp. 277, 278).
THE JAVELIN BAT.[236]
In the genus Phyllostoma the nasal appendages are well developed; there is a distinct horseshoe-shaped piece in front, and above the nostrils rises a large lance-shaped leaf. The middle of the lower lip shows a triangular naked patch with warty margins. The ears are of moderate length and quite separate; the tail is much shorter than the interfemoral membrane; and the first phalanx of the middle finger is less than half the length of the metacarpal bone. There are, as usual in this family, four incisors in each jaw; the canines are large and powerful, and the lower jaw has only two premolars on each side. The true molars are well developed, and show strong W-shaped cusps.
The Javelin Bat, which lives in all parts of tropical America, and also occurs in the West Indies, is a large species, measuring more than five inches in total length, and nearly twenty-three inches in expanse of wing. Its fur is usually of a uniform brown colour; its ears of moderate size, somewhat pointed, strongly excavated on the outside below the apex, and with a lance-shaped tragus; the short tail extends about one-third of the length of the interfemoral membrane, which is stretched straight across between the long heel-spurs.
We have already referred at some length to the habits of this species in connection with the charge of blood-sucking that has been brought against it, and stated that when examined only remains of insects are found in its stomach. It is described as having a lofty and powerful, although not rapid flight. These Bats frequently make their way into rooms through the open windows, when they fly about rather noisily. In the neighbourhood of houses they sleep during the day among the leaf-stalks of the cocoa-nut palms; in the open country they resort to the hollow trunks of trees.
Numerous species nearly allied to this occur in Brazil and other parts of America, such as Phyllostoma discolor and elongatum, Mimon Bennettii and megalotis, in which the chin bears two warts separated by a furrow; Tylostoma Childreni and crenulatum, with only two lower incisors; Carollia brevicauda, in which the middle of the horseshoe is scarcely distinct from the upper lip; Rhinophylla pumilio, in which the tail is entirely wanting; and Phylloderma stenops with three instead of two premolars on each side in the lower jaw.
THE VAMPIRE BAT.[237]
The genus Vampyrus differs from Phyllostoma and its allies (except the last) by the presence of three premolars on each side in the lower jaw. The lower lip has two broad warts separated by a furrow; the ears are large and separate; the first joint of the middle finger is more than half as long as the metacarpal bone; and the tail is altogether wanting. The nasal appendage has the horseshoe part well developed, with the margin free and quite distinct from the upper lip.
The Vampire, which was one of the earliest known species of these American Bats, and is also the largest of all, is by no means an amiable-looking animal. Its head is considerably elongated; the nose-leaf is long and pointed; the wings reach the base of the outer toe, and the middle of the hinder margin of the interfemoral membrane projects in a little point, although, as already stated, there is no tail to cause any such projection. The fur, which is long and soft, is usually chestnut-brown above and pale beneath. The length of the head and body in this Bat is about five and a half inches. From various considerations, no doubt in part from its large size and ugliness, this Bat has always been regarded as one of the most noxious of the blood-suckers of its family, and, in fact, it owes its name of Vampire to the belief in its sanguinary nature. But Mr. Bates, who certainly had good opportunities of observing it, acquits the Vampire of this charge. In describing his residence at Ega, on the Upper Amazon, he says:--“The Vampire was here by far the most abundant of the family of Leaf-nosed Bats. It is the largest of all the South American species, measuring twenty-eight inches in expanse of wing. Nothing in animal physiognomy can be more hideous than the countenance of this creature when viewed from the front; the large leathery ears standing out from the sides and top of the head, the erect spear-shaped appendage on the tip of the nose, the grin, and the glistening black eye, all combining to make up a figure that reminds one of some mocking imp of fable. No wonder that imaginative people have inferred diabolical instincts on the part of so ugly an animal. The Vampire, however, is the most harmless of all Bats, and its inoffensive character is well known to residents on the banks of the Amazons. I found two distinct species of it, one having the fur of a blackish colour, the other of a ruddy hue, and ascertained that both feed chiefly on fruits. The church at Ega was the head-quarters of both kinds. I used to see them, as I sat at my door during the short evening twilight, trooping forth by scores from a large open window at the back of the altar, twittering cheerfully as they sped off to the borders of the forest. They sometimes enter houses. The first time I saw one in my chamber, wheeling heavily round and round, I mistook it for a Pigeon, thinking that a tame one had escaped from the premises of one of my neighbours. I opened the stomachs of several of these Bats, and found them to contain a mass of pulp and seeds of fruits, mingled with a few remains of insects. The natives say they devour ripe cajús and guavas on trees in the gardens; but, on comparing the seeds taken from their stomachs with those of all cultivated trees at Ega, I found they were unlike any of them; it is therefore probable that they generally resort to the forest to feed, coming to the village in the morning to sleep, because they find it more secure from animals of prey than their natural abodes, in the woods.”
The two forms referred to by Mr. Bates in the above extract were probably only colour varieties of Vampyrus spectrum, but several nearly related species occur in tropical America. Thus, Chrotopterus auritus differs from the preceding only in having a short tail like that of Phyllostoma, and the second lower premolar small, and placed within the line of the teeth; Lophostoma sylvicola, amblyotis, and bidens, all from Brazil, have the second lower premolar small, but in the row, the horseshoe only developed at the sides, the lower lip as in Phyllostoma, the first phalanx of the middle finger a little shorter than the metacarpal, and only two incisors in the lower jaw; Schizostoma minutum, elongatum, and Behnii, whilst agreeing with Lophostoma in the proportion of the first phalanx of the middle finger, have the horseshoe and lower lip as in Vampyrus; and Trachyops cirrhosus has the lower margin of the horseshoe indistinct, the lower lip with a double row of warts and a deep furrow, and the second lower premolar very small, and placed within the line of the row of teeth. These Bats are all inhabitants of the tropical parts of America.
Neuwied’s Large-leafed Bat (Macrophyllum Neuwiedii) is one of the few species of the present family in which the tail is respectably developed. The ears are of moderate size and separate; the horseshoe is well developed, and the nose-leaf very long, lance-shaped, and pointed. The dentition is as in Phyllostoma. This is a small Bat, measuring only about three inches and one-sixth in total length, of which the tail occupies one inch and one-third. The fur is of a sooty-brown colour, paler beneath; the nose-leaf is darker, and the membranes lighter in colour than the body; the interfemoral membrane has about half a dozen curved lines of small dark points towards its apex. Neuwied’s Bat was discovered by Prince Maximilian in Brazil in the forests of the banks of the Moucouri River. He describes it as not very abundant, and as passing the day clinging to rocks and the trunks of trees. Its stomach contained remains of insects.
The Large-eared Spear-nosed Bat (Lonchorhina aurita), an allied species with a long tail and a very long nose-leaf, is a native of the West Indies. The tail traverses the interfemoral membrane in the fashion of that of a Vespertilionid Bat. The nose-leaf has a distinct rib running up its middle, and at its base there is a deep pit divided into two by a partition on each side of which are the nostrils, and the place of the horseshoe is taken by a curious three-leaved process which stands out in front of the nostrils.
THE GREAT-EARED LEAF BAT.[238]
The Great-eared Leaf Bat, an inhabitant of St. Domingo and Jamaica, is the type of a remarkable little genus, characterised by having the ears very large, membranous, and united at the base by a membrane; the nasal appendage erect; the interfemoral membrane large, cut out behind in a broad curve running from the tip of one spur to the other; and the tail long, projecting by its last joint beyond the interfemoral membrane. The head is rather long, and the jaws armed with four incisors in each--the intermediate ones in the upper jaw being larger than the lateral--two premolars in the upper, and three in the lower jaw, and three true molars in each jaw. The species of this genus occur in the West Indies, Mexico, and California.
The Great-eared Leaf Bat (Macrotus Waterhousii) is a small species, the head and body measuring two inches and a half in length, and the tail one inch and one-sixth. Its fur is of a mouse-colour, paler beneath, and the nose-leaf is lance-shaped.
Our knowledge of the habits of this Bat is chiefly derived from observations made in Jamaica by Mr. Gosse and Mr. Osburn. The former says that it is one of the commonest of the Jamaica Chiroptera, and that it is more addicted than any other species to visiting lighted rooms at night. Mr. Osburn obtained it in abundance from caves; and he adds that although it occurs in houses, it there always inhabits the cellars, and is never found in roofs. The great breadth of the wings gives it during flight an appearance of being larger than it really is, and its flight, according to Mr. Gosse, is not so noiseless as in Bats generally, but accompanied by an audible rushing sound. When on the ground, it makes no attempt to crawl, but springs at once into the air, and takes flight as readily as a bird. Mr. Osburn obtained many females with their young, and describes the mode in which the latter adhere to their mothers. He says the nipple was held by the little hooked teeth of the young animal, while the fur, or even the thigh of the opposite side, was grasped by its feet, so that the young Bat lay diagonally across its mother’s belly. The food of the Great-eared Leaf Bat consists for the most part of insects. Mr. Osburn found in the stomach of one a yellowish mass, with fragments of the hard parts of insects, among which were two short legs with strong claws, which probably belonged to some species of Orthoptera.
From one observation it would appear that this Bat is supposed sometimes to feed on fruits. Mr. Osburn says that at Mount Pleasant, St. Ann’s, his attention was called to a number of spirts on the wall in an open verandah, on examining which he says he detected seeds of the fustic berry sticking to the wall. He was informed that they were produced by these Bats, which came in at night, and hitched themselves up, when a chewing might be distinctly heard, and then these splashes on the wall. One let the legs and wings of a large Grasshopper drop. The berries said to be particularly affected by these Bats were those of the fustic (Morus tinctoria), the bread-nut (Brosimum alicastrum), and the rose-apple (Eugenia jambos), all of which are mentioned by Mr. Osburn as favourite articles of food with Stenoderma perspicillatum, a true fruit-eating Bat.[239]
THE SORICINE BAT.[240]
Agreeing with the Phyllostomes and Vampires in the form of the molar teeth, the general form of the muzzle, the presence of a nose-leaf and tragus, and some other characters, the Glossophagæ exhibit some striking peculiarities which serve to distinguish them from these and all other Bats. Foremost among these is the structure of the tongue, which is very singular. It is a long, somewhat compressed fleshy cylinder beset with reversed hairs, and capable of being pushed out of the mouth to a considerable distance. In the fresh state, according to Rengger, it has a furrow running along the upper surface, and this, he thought, rendered it specially applicable to the purpose of sucking blood, which was formerly supposed to be a habit of all these Bats. The lower lip is cleft, and the margins of the fissure furnished with warts, a construction which also contributed to raise a suspicion of the sanguinary habits of the animals. The horseshoe-shaped part of the nose-leaf is very imperfectly developed, and the organ consists chiefly of the lance-shaped leaf; there are four incisor teeth in a close row in each jaw, the two middle ones in the upper jaw larger and broader than the others; the upper jaw has two and the lower three premolars on each side, and there are three true molars on each side in both jaws.
The Soricine Bat has received a great number of names; at least, numerous supposed species founded upon slight differences of colour, &c., are regarded by Professor Peters as all referable to the species described by Pallas, in 1766, under the name of Vespertilio soricinus. It is a small Bat about two inches and a quarter long including the tail, which measures about one-sixth of an inch, and is enclosed within the interfemoral membrane. The ears are of moderate size and separate, with small, pointed tragi; and the body is clothed with a rather long, soft, and thick fur, usually of a rusty greyish-brown colour, paler on the lower surface. This Bat inhabits the whole of the warmer part of South America, extending from the Brazilian coast to the Andes, and northwards into Venezuela and Guatemala. It is said to feed chiefly on insects, but probably, like the following species, diversifies its food by eating succulent fruits, this being apparently the purpose for which these animals are endowed with their peculiar tongue.
REDMAN’S BAT.[241]
The genus Monophyllus is nearly allied to Glossophaga, but has the incisor teeth in pairs, and the lower ones exceedingly small. The interfemoral membrane forms a narrow border running up the legs, and crossing from side to side; and the tail, although short, projects beyond the membrane. The teeth are--incisors, (2–2)/(2–2), canines, (1–1)/(1–1), premolars, (2–2)/(3–3), molars, (3–3)/(3–3). The only known species is Redman’s Bat (Monophyllus Redmanii), in which the head and body measure about two inches and one-sixth in length. The expanse of wing is about twelve inches; the fur, which is thick, soft, and glossy, is greyish-brown above with the tips of the hairs slightly hoary, and dusky grey tipped with greyish-white on the lower surface. The membranes are dark brown. This species occurs in Jamaica and Cuba.
It was found by Mr. Osburn at Cairo, in Jamaica. He describes it as exceedingly fierce, drawing blood readily from the back of the hand of its captor. Its activity was beyond anything he had seen in Chiroptera. It ran round the box in which it was placed by a series of little jumps, with almost the quickness of a Mouse, and jumped with the agility of a bird. “On placing it under a glass,” he says, “after its first efforts had a little subsided, I saw its tongue projected very rapidly to the board. It seemed to me to be using an additional sense to ascertain the nature of the unusual substance on which it was resting. It frequently stretched its neck and head upwards, the nose-leaf and round ears in motion, as if trying to ascertain whether there was an aperture above, its bright little eyes piercing with eagerness, and panting like a Mouse.” Mr. Osburn’s observations on the specimens which he had in captivity seem to lead to the conclusion that this Bat feeds on soft fruits, and that its long and peculiar tongue is employed in sucking up their pulp.
Ischnoglossa nivalis has the incisors in pairs and no tail. The described specimen was obtained near the snow line on the Pic d’Orizaba, in Mexico.
SEZEKORN’S LEAF BAT.[242]
The genus to which this Bat belongs is distinguished from all the preceding ones in the group of Glossophogæ by the absence or imperfection of the zygomatic arch in the skull. In its dentition it resembles Glossophagæ. The interfemoral membrane is merely a narrow border round the legs, and the calcaneal spurs are very short, or altogether wanting. There is a very short tail, which, however, projects beyond the interfemoral membrane; the nose-leaf is extremely short, or, indeed, almost rudimentary; and the tongue is very long, pointed, and armed at the sides towards the tip with acute spines turned backwards. This species was discovered in Cuba; it occurs also in Jamaica.[243]
In the latter island Mr. Osburn found it inhabiting a cave in immense numbers, flying about and swarming on the roof and walls like Bees in a hive. The floor of the cavern was covered with bread-nut kernels and munched berries of the clammy cherry (Cordia collocasia). The Bat chirps and squeaks like a bird.
Mr. Osburn describes its manners in confinement as follows:--At first the Bats were restless and fierce, biting violently. When exhausted and quiet he gave them water, which “they drank eagerly, protruding the tongue--the lip hollowed spoon-shape, and the bristles evidently taking up a great quantity.” The fruit of the clammy cherry being offered to them, they took no notice of it until Mr. Osburn thought of breaking the skin, when the one he presented it to at last seemed to understand the position of affairs, and licked at it vigorously. “The tongue,” says Mr. Osburn, “was rapidly protruded and drawn in again, and the juice and softer pulp cleared away with great rapidity. I noticed that he was very particular in cleaning out the bit of loose skin of the berry, and licked my fingers of the juice spilt on them, carefully cleaning out any that had collected under the nail. The sensation was not at all unpleasant, the tongue feeling soft and spongy, with a slight scratching from the bristles. I then got another berry. The Bat was hanging from the edge of the box, its ventral surface against the side; and as I held the berry a little off, so as to see the action of the tongue, it had, whilst feeding, to bend the neck, so as to raise the head a little. This seemed to fatigue it. It therefore raised itself on one wrist, and turned round, so that its back was against the box’s side; but as it did not change the position of the feet, of course the legs crossed.... In this odd position it seemed perfectly at ease, and went on licking at a fresh berry with great relish.... It seized it with its teeth savagely, and then shifted it to one side of the mouth, so that the long sharp canines of one side and the blunt molars held the berry.... This left room for the tongue still to be protruded; for from the arrangement of the minute lower incisors in a concave, the molars can be nearly closed, so as to hold an object, and the tongue still have room for protrusion. The little body trembled with the eagerness of his actions. As the pulp and juice it could thus reach became exhausted, I expected it would drop it; but, to my surprise, it brought up the wrists to the muzzle, took the berry between them, gave it two or three energetic bites, and then held the berry off. So I now understood what the long thumbs were for; for they applied themselves dexterously to the berry, held it firmly, and then, as it appeared to me, by a reverse action of the two wrists, the berry was turned round, a fresh hold taken by the teeth, and the same licking process renewed, till the seed in the centre was cleaned of the pulp, all but the little bit which served for the last tooth-hold. It was then dropped, and the eager little muzzle raised for more. I supplied another, and soon I had a little heap of seeds, exactly like those found in the cave.” This account is particularly interesting, and gives us a clear idea of the proceedings of these curious Bats. Mr. Osburn remarks that the Bats when holding the berries greatly reminded him of Monkeys, and on placing them among the twigs of the cherry, their climbing habits seem to have increased the resemblance.[244]
THE SPECTACLED STENODERM.[245]
A peculiar group of this family is formed by the genus Stenoderma and its allies. In these Bats the muzzle is short, and the molar teeth do not show the W-like pattern characteristic of the preceding forms, but generally have some sharp points and a cutting edge on the outside. The tail, when present, is very short, and the interfemoral membrane is deeply cut out behind, so much so in many cases as to form a mere narrow border to the legs. The nasal appendages consist of a lance-shaped leaf springing from the middle of a regular horseshoe; and the ears are separate, and furnished with a tragus. The Stenoderms have been divided by authors into several genera, but the characters upon which these are founded are for the most part so minute and uncertain that it would be a mere waste of time to attempt to give them here.
The Spectacled Stenoderm (see p. 264) is one of the best-known species of this group, and inhabits the larger islands of the West Indies, such as Cuba, St. Domingo, and Jamaica, as well as the continental regions of Guiana and Brazil. It is a large species, measuring from four inches to four inches and a half in length, and from sixteen inches to twenty inches in expanse of wing. Its fur is brown, and there is a whitish arch above each eye. The nose-leaf, although lance-shaped, is somewhat oblong in its form, having the sides nearly parallel for some distance; and the wing-membranes are black. There is no tail. The species belongs to the sub-genus Artibeus.
This species usually inhabits caves and recesses in the rocks, in the former case generally keeping near the mouth of the cave; but when the geological structure of a district is unfavourable for the formation of caves, it takes up its abode during the day under the fronds of the cocoa-nut palm. At Aquatta Vale, in Jamaica, Mr. Osburn found these Bats clustering on the cocoa-nut trees so thickly, and in such numbers, that a single shot brought down twenty-two, while many others flew off, and took refuge in neighbouring trees. The food of this species consists of various fruits, the seeds and kernels of which are seen in abundance on the floors of the places where they repose during the day. Mr. Osburn mentions the bread-nut (Brosimum), the negro-cherry (Cordia callococca), the mango, and the rose-apple (Eugenia jambos), as fruits upon which it feeds in Jamaica. He also obtained from the intestines of several specimens numerous small seeds, which he believed to be those of the fustic (Morus tinctoria). The same observer noticed a curious habit of the species when alarmed--the little round ears were kept in a state of rapid motion, but alternately, so as to produce an effect like that of a person rolling his eyes different ways. The nose-leaf was also slightly moved.
THE JAMAICAN STENODERM.[246]
This is very nearly allied to the preceding species, from which it differs in its smaller size, being only about two inches and a half long, and in the form of the nose-leaf, which is lance-shaped, with regularly curved margins. It varies considerably in colour, but is usually of various shades of brown.
Mr. Gosse observed the habits of this and the preceding Bat in Jamaica, and describes them as exhibiting a special partiality for the fruit of the Achras sapota, called in Jamaica the naseberry, a preference already observed by Mr. A. Ricord in the case of the Spectacled Stenoderm. Mr. Gosse says:--“About a quarter of an hour after the sun has disappeared, and while the western horizon is yet glowing with those effulgent peak-like clouds which only a tropical sunset displays, we discover, by attentively watching the tree, the Bats begin to visit it. First one comes, takes a rapid flight around the tree, darts once or twice through the dense foliage, and winging away is lost in the light of the sky. Another and another comes immediately, and performs the same evolutions; and as the glory of the west fades away to a warm ruddy brown, like the blush of a mulatto girl, many dusky forms are discerned flitting round and round. By carefully following the flight of an individual with the eye, we perceive that now and then he alights for a moment on some object at the extremity of a bunch of leaves; but no sooner has the eye rested on the spot than the sooty wings are again spread, and he is pursuing his giddy course with his fellows. The object of his attention is a ripe naseberry, nestled in the midst of that rosette of leaves. Occasionally the weight of the suspended Bat dislodges the ripe fruit, and it falls to the ground, splitting with the shock. On picking it up, we see that it has been just bitten, not gnawed, as by the rodent incisors of a Mouse, but nibbled in a ragged manner. Though the Vampires often eat the fruit on the tree in this manner, detaching minute morsels, and again and again returning for more, it appears that not seldom they succeed in tearing out a large piece, which they carry away; for fragments of naseberry of considerable size, partly eaten by a Bat, are frequently found at the distance of half a mile from the nearest naseberry tree, dropped on the high road.” Mr. Gosse adds that this Bat also feeds on the rose-apple, and Mr. Osborn describes it as consuming all the same fruits as the preceding species.[247]
THE DESMODUS.[248]
The Desmodonts are in some respects among the most remarkable forms of Bats; indeed, their characters are so peculiar that it may be a question whether they ought not to form a distinct family in the order Chiroptera. By some zoologists, indeed, this course has been adopted, but as they agree with the Phyllostomidæ in the presence of nasal appendages, and in the possession of three phalanges in the middle finger, we have preferred to leave them in that family, at the same time indicating their striking divergences from all its other members.
The dentition in these Bats is most singular, and as we shall see, its peculiarities are so associated with the exceptional habits of the animal, as to have far greater weight in the question of classification than we have accorded to the dental characters in other families. In fact these peculiarities, in combination with certain points of internal anatomy, are so remarkable that Professor Huxley has suggested the formation for the Desmodonts of a distinct group (Hæmatophilina) of the Microchiroptera, which he apparently regards as equivalent in classificational value to all the rest of the sub-order taken together.
The remarkable conformation of the teeth will be easily seen by reference to the annexed figure. The upper incisor teeth, four[249] in number in the young animal, become reduced to two in the adult, but these are of enormous size, prominent, triangular, and very sharp. The lower incisors, on the contrary, are small and have a two-lobed crown. The canines of the upper jaw are nearly of the same form as the incisors, but rather smaller; those of the lower jaw present no remarkable peculiarity. The molar series of teeth, however, are most peculiar--there are two in the upper and three in the lower jaw, but the whole of them are small, compressed, sharp-edged, and furnished with only a single root, thus presenting the characters of premolars, as which, indeed, they are regarded by some writers. If this view of their nature be correct the Desmodonts have no true molars.
In general characters these Bats approach the Stenoderms. The tail is entirely deficient; the interfemoral membrane forms a mere border to the legs; the ears are of moderate size and furnished with a small tragus; and the nasal appendage consists only of the part analogous to the horseshoe in other genera, the upper leaf being absent. The thumb is very long and strong. The only species of the genus Desmodus (D. rufus) measures about four inches in length, and some fifteen or sixteen inches in expanse of wing. The fur varies considerably in colour, but generally shows various tints of brown, from a reddish-brown, as in the specimen originally described by Prince Maximilian, through a plain brown, to ashy-brown and mouse-colour, variations which have induced zoologists to describe several distinct species, now, however, generally regarded as identical. This species in its various forms seems to be very generally distributed in all the warmer parts of South America, from Chili to Guiana. As already stated, it appears to be the only species that has been detected in the act of blood-sucking; and by some of the most recent authorities it and its near ally, Diphylla ecaudata, are believed to be the only South American Bats which are really guilty of that atrocity.
Dr. Hensel, who has discussed this matter at some length, in connection with his observations on the Bats of Brazil, remarks that the teeth of most of the Phyllostomidæ are like those of the true Carnivora, and the wounds inflicted by them, as may easily be observed by the captor of one of them, are of the same kind as those produced by the teeth of a small Carnivore. In the latter, as he says, there is no loss of substance; the bite consists usually of four punctures, where the canine teeth have pierced the skin, and severe bleeding occurs only when these teeth have penetrated to some depth, and injured one or more of the larger vessels.
But the wounds observed on Horses or Mules that have been bitten by blood-sucking Bats are, as already stated, of quite a different character. They form small oval surfaces, which are but slightly sunken, the surface of the cut not being perpendicular to that of the spot bitten, as would be the case in wounds produced by long canine teeth, but in a general way parallel to it. A similar wound would be produced by lifting a small portion of skin by means of a pair of forceps, and then passing a knife along the surface of the skin, as if to shave it, but so as to cut away the raised portion. By a cut or bite of this kind, notwithstanding its being so superficial, a portion of substance is always lost, a great number of fine cutaneous vessels are cut through, and an abundant and long-continued bleeding is caused.[250] Such wounds, says Dr. Hensel, can be produced only by large, peculiarly shovel-like, and very sharp incisor teeth, and such teeth occur only in the allied genera Desmodus and Diphylla. With the latter he had no acquaintance, but he obtained Desmodus rufus in abundance. He says it usually lives in cavities in the rocks, but sometimes in large hollow trees. “In capturing these animals,” he adds, “I have often had the opportunity of observing the wounds that they inflicted on the noses of my Dogs which tried to seize them, or on my own hands, and found that they perfectly resembled those of the Horses bitten by the blood-suckers. The creatures bite with the rapidity of lightning, and even when they seem merely to touch the skin, a piece of it is found to be deficient. They cannot therefore hold fast with their teeth, as all other Phyllostomidæ do, for these, when they are captured, in their rage seize with their teeth any object within their reach, and hold it for some time.” It would appear, especially from the rudimentary state of their molar teeth, that these Bats cannot be supposed to prey upon insects, no remains of which have ever been found in their stomachs, and their excrements consist solely of a black, pitch-like paste, evidently digested blood. This is evacuated near the entrance of the caves in which the creatures live, and while they are waiting until the darkness outside is sufficient for them to start on their piratical excursions. The floor at such a place is found covered with a layer of the above-mentioned black mass, which may attain a thickness of a foot or more. Dr. Hensel mentions that a large Dog, after paying a visit to one of the caverns haunted by these Bats, looked as if he had got long black boots on. The same writer is of opinion that the Bats must obtain the greater part of their food by capturing and sucking the blood of the smaller warm-blooded animals. As the large domestic animals are not indigenous to America, it is probable that they only furnish an occasional meal to some of the great swarms of these Bats that infest the country.
That the Desmodus is specially organised for a peculiar diet is shown by the extraordinary structure of its stomach, which, as described by Professor Huxley, whose observations are confirmed by Professor Peters, differs from that of any other Mammal. The gullet (g in figure) is exceedingly narrow, and opens into a transversely elongated tubular stomach, which passes directly on the right side into the intestine (i), the duodenum and stomach not being separated by any pyloric constriction, and limit of the stomach in this direction being indicated solely by the insertion of the gall-ducts at a point only one-fifth of an inch from the opening of the gullet. The other, or cardiac division of the stomach, on the contrary, is enormously developed, forming an elongated and convoluted cæcum (c) several inches long, and becoming considerably wider than at its origin. In one specimen examined, the body of the Bat measured only three inches and one-fifth in length; the intestine, from the pylorus to its termination, was eleven inches long; while the above-mentioned cæcal portion, when straightened out, was six inches and a half in length, or twice as long as the body, and nearly two-thirds the length of the intestine. Professor Peters describes the cardiac cæcum in the specimen examined by him as only from one to two inches long. It may, perhaps, have belonged to a distinct species. The stomach in the Frugivorous Pteropidæ is elongated and tubular, no doubt for the reception of the huge quantity of vegetable food which they require to support their existence. In the ordinary Insectivorous Bats the organ is small and globular, with the pyloric and cardiac orifices near each other, the nourishment afforded by their usual diet being in a tolerably concentrated form and firm condition. The extraordinary cæcum of the blood-suckers, no doubt, serves as a reservoir for their fluid nutriment, in which it may be stored for a time almost unchanged, and gradually subjected to the process of digestion.
The second species of blood-sucking Bat mentioned in the earlier part of this article, Diphylla ecaudata, agrees with the Desmodus in its dentition and general characters, but is entirely destitute of interfemoral membrane, and has the lower incisors pectinate.
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The following table of the classification of Bats here adopted will assist the reader in the comprehension of the information given in the preceding pages:--
SUB-ORDER I.--MEGACHIROPTERA.
Family I.--PTEROPIDÆ.
+Group 1.+--Pteropi.--Tongue moderate; molars well developed. Genera.--Pteropus, Cynopterus, Cynonycteris, Harpyia, Epomophorus, Hypsignathus, and Cephalotes. +Group 2.+--Macroglossi.--Tongue very long; molars very small. Genera.--Macroglossus, Eonycteris, and Notopteris.
SUB-ORDER II.--MICROCHIROPTERA.
A.--Vespertilionine Alliance.
Family II.--RHINOLOPHIDÆ.
Sub-family 1.--Rhinolophinæ.--First toe with two, remainder with three phalanges. Genus.--Rhinolophus.
Sub-Family 2.--Phyllorhininæ. Toes equal, each of two phalanges. Genera.--Cœlops, Phyllorhina, Rhinonycteris, and Triænops.
Family III.--NYCTERIDÆ.
Sub-family 1.--Nycterinæ.--Nasal apparatus concealed; tail long. Genus.--Nycteris.
Sub-family 2.--Megaderminæ.--Nose-leaf distinct; tail short. Genus.--Megaderma.
Family IV.--VESPERTILIONIDÆ.
+Group 1.+--Vespertiliones.--Crown of head flat, or nearly so; upper incisors close to canines; ears moderate, separate. Genera.--Vespertilio, Vesperugo, Chalinolobus, Scotophilus, Nyeticejus, Atalapha, and Kerivoula. +Group 2.+--Plecoti.--Head and incisors as above; ears very large, generally united. Genera--Plecotus, Synotus, Histiotus, Otonycteris, Coriuorhinus, Nyctophilus, and Antrozous. +Group 3.+--Miniopteri.--Crown greatly elevated; upper incisors separated from canines. Genera.--Natalus, Miniopterus, and Thyroptera.
B.--Emballonurine Alliance.
Family V.--EMBALLONURIDÆ.
Sub-family 1.--Emballonurinæ.--Tail slender; upper incisors weak. +Group 1.+--Emballonuræ.--Frontal bones convex. Genera.--Furia, Saccopteryx, Rhynchonycteris, and Emballonura. +Group 2.+--Taphozoi.--Frontal bones with a concavity; pre-maxillary bones separate in front. Genera.--Coleura, Taphozous, Diclidurus. +Group 3.+--Rhinopomata.--Frontal bones concave; pre-maxillaries united (a small nose-leaf). Genus.--Rhinopoma. +Group 4.+--Noctiliones.--First phalanx of middle finger extended in repose. Genus.--Noctilio.
Sub-family 2.--Molossinæ.--Tail thick; upper incisors strong. +Group 5.+--Molossi.--Middle finger with two phalanges. Genera.--Mormopterus, Molossus, Nyctinomus, and Chiromeles. +Group 6.+--Mystacinæ.--Middle finger with three phalanges. Genus.--Mystacina.
Family VI.--PHYLLOSTOMIDÆ.
Sub-family 1.--Lobostominæ.--Nostrils in front of muzzle; chin with erect cutaneous ridges. Genera.--Chilonycteris, Pteronetus, Mormops.
Sub-family 2.--Phyllostominæ.--Nostrils on upper surface of muzzle; chin with warts. +Group 1.+--Vampyri.--Molars with W-shaped cusps; four upper incisors; muzzle long; tongue moderate. Genera.--Macrotus, Lonchorhina, Macrophyllum, Vampyrus, Schizostoma, Lophostoma, Trachyops, Phyllostoma, Carollia, Rhinophylla. +Group 2.+--Glossophagæ.--Like the Vampyri, but tongue very long, and lower lip divided by a deep groove. Genera.--Glossophaga, Monophyllus, Ischnoglossa, Phyllonycteris, Lonchoglossa, Glossonycteris. +Group 3.+--Stenodermata.--Muzzle short; molars with a cutting outer edge; four upper incisors. Genera.--Stenoderma, Artibeus, Phyllops, Vampyrops, Pygoderma, Ametrida, Chiroderma, Sturnira, Brachyphylla, Centurio. +Group 4.+--Desmodontes.--No true molars; two upper incisors. Genera.--Desmodus, Diphylla.
We have already remarked that of these families the Vespertilionidæ may be regarded as the types of the whole order; they realise all the notions that we form in our minds when we speak of “a Bat,” and this with the greatest simplicity, or with the smallest amount of complication from subordinate characters. Next to them in this respect come some of the Emballonuridæ. The other families group themselves round these, or the whole of the other Microchiroptera may be said to surround the Vespertilionidæ. Mr. Dobson, accepting the notion of the origin of organic forms by a process of evolution, assumes an unknown group of ancestral forms (Palæochiroptera) from which in the first place the Vespertilionidæ and Emballonuridæ diverge, forming the roots of his two “alliances.” From the Emballonuridæ proceed the Phyllostomidæ, and from the Vespertilionidæ the Nycteridæ and Rhinolophidæ. From this point of view these Bats may be regarded as allied to the Insectivora through some unknown common ancestors; but what these may have been, or by what stages the Bat-type originated from the ordinary quadruped, it is very difficult to imagine. The facts of geographical distribution go far, however, to confirm the view that the Vespertilionidæ and Emballonuridæ are the central and oldest types of Bats; their distribution is world-wide, and even some nearly allied forms are found in very distant parts of the world. The other families are more restricted in their range, the Nycteridæ and Rhinolophidæ being confined to the Eastern, and the Phyllostomidæ to the Western hemisphere, and chiefly to the warmer zones, whereas the Vespertilionidæ extend much further to the north.
The Pteropidæ, or Frugivorous Bats, however, cannot well be brought into this scheme of descent. They stand completely isolated from the rest of the order, and their peculiar distribution would almost seem to indicate that their origin and relationships were distinct from those of the other Bats. Their range, which sweeps round the shores of the Indian Ocean from the Cape of Good Hope to Australia, and extends, perhaps somewhat exceptionally, into the islands of the Pacific, although it cannot be said to coincide with that of the Lemuroids, being so much wider, at least includes the whole of the localities in which the latter are met with; and if the Lemuroids are really, as seems probable, segregated descendants of a great fauna which inhabited the supposed sunken continent of “Lemuria,” the same origin may fairly be ascribed to the Pteropidæ, and their wider distribution may be accounted for by their much greater power of locomotion. In connection with this it is interesting to note the strong Lemurian resemblances presented by many of the Pteropidæ; and further, the sort of common point of junction between the Lemuroids, the Pteropids, and the Insectivora, furnished by that curious animal the Galeopithecus, or Flying Lemur, which is also still an inhabitant of a region haunted by Lemuroids and Pteropine Bats. The Pteropidæ thus seem to stand quite apart from the other Bats. From a genealogical point of view, which indeed is that which we always take of the relationships of animals, whether we believe in the doctrine of descent or not, we may ask whether the two sub-orders of Bats have not been realised in their present form through two quite different series of modifications.
The appeal to fossil evidence, which in some cases leads to satisfactory results, gives us no clue to the origin of the different groups of Bats. Of the Pteropidæ no fossil remains are known. Of the other families the most ancient remains are, as might be expected, those of the Vespertilionidæ, several species of which have been found in Miocene beds at Mayence and in the south of France, and even in the Eocene gypsum deposits of the Paris basin. Other bones identical with those of species now living in the same localities have been detected in bone-caves in various parts of Europe. Bones of a Rhinolophus have occurred in the cavern of “Kent’s Hole,” near Torquay; and the celebrated bone-caves Brazil have furnished numerous remains of Bats, all of which, however, are referable to the peculiarly South American family Phyllostomidæ. Thus, so far as we are acquainted with them, the fossil remains of Bats, even the most ancient, indicate only forms more or less nearly related to those still existing in the same localities, and furnish us with no means even of speculating upon the course of events by which, so to speak, the type of the Chiroptera was evolved.
W. S. DALLAS.
ORDER INSECTIVORA.