Notice of the predatory and sanguivorous habits of the Bats of the genus _Megaderma_, with some Remarks on the blood-sucking propensities of other Vespertilionidæ

1842.] on the North-Western Frontier. 255 of the country is earnestly solicited, since it is only by wide -spread observations that justice can be done to the subject, and such observations it is quite impossible for any single individual to collect satisfactorily. Saharanpore, 5th April, 1842. Notice of the predatory and sanguivorous habits of the Bats of the genus Megaderma, with some Remarks on the blood-sucking propensities of other Vespertilionidod. By Edward Blyth, Curator to the Asiatic Society. Chancing, one evening, to observe arather large Bat enter an outhouse, from which there was no other egress than by the door-way, Iwas fortunate in being able to procure alight, and thus to proceed to the capture of the animal. Upon finding itself pursued, it took three or four turns round the apartment, when down dropped what at the moment Isupposed to be its young, and which Ideposited in my handkerchief. After asomewhat tedious chase, Ithen secured the object of my pursuit, which proved to be afine pregnant female of Megaderma lyra. Ithen looked to the other Bat which Ihad picked up, and to my considerable surprise, found it to be asmall Vespertilio, nearly allied to the European V. pipistrellus,which is exceedingly abundant not only here, but apparently throughout India, being the same, also, to all appearance, as asmall species which my friend Dr. Cantor procured in Chusan :the individual now referred to was feeble from loss of blood, which it was evident the Megaderma had been sucking from alarge and still bleeding wound under and behind the ear ;and the very obviously suctorial form of the mouth of the Vampyre was of itself sufficient to hint the strong probability of such being the case. During the very short time that elapsed before Ientered the out-house, it did not appear that the depredator had once alighted ;but Iam satisfied that it sucked the vital current from its victim as it flew, having probably seized it on the wing, and that it was seeking aquiet nook where it might devour the body at leisure. Ikept both animals wrapped separately in my handkerchief till the next morning, when procuring aconvenient cage, I first put in the Megaderma, and after observing it some time, Iplaced the 256 Notice of the Sanguivorous habits of the [No. 123. other Bat with it. No sooner was the latter perceived, than the other fastened on it with the ferocity of aTiger, again seizing it behind the ear, and made several efforts to fly off with it, but finding that it must needs stay within the precincts of the cage, it soon hung by the hind-legs to one side of its prison, and after sucking its victim till no more blood was left, commenced devouring it, and soon left nothing but the head and some portions of the limbs. The voidings observed very shortly afterwards in its cage resembled clotted blood, which will explain the statement of Steedman and others concerning masses of congealed blood being always observed near apatient who has been attacked by aSouth American Vampyre. Such, then, is the mode of subsistence of the Megaderms. The sanguivorous propensities of certain Bats inhabiting South America have long been notorious, but the fact has not heretofore been observed of any in the old world* ;and the circumstance of one kind of Bat preying upon another is altogether new, though Ithink it not improbable that the same will be found to obtain (to agreater or less extent) among the larger species, if not throughout the whole extensive allied genus of Rhinolophus, (or the horse-shoe Bats,) which, like Megaderma, are peculiar to the Eastern world. It may appear strange, that with the multitudinous attestations ascribing bloodsucking habits to certain Bats of South America, naturalists have been found unwilling to credit the statement, as instanced by Mr. W. S. McLeay, who, in anote appended to the remark that a *There are, it is true, certain vague statements, but quite unworthy of credit, ascribing sanguivorous habits to the Pteropodes. Thus De Vaux, in his *Letters from the Mauritius,' (p. 65), describes these animals to "feed indiscriminately on fruit, small warm-blooded animals, and insects, as well as to suck the blood of men and cattle." But were this the case, the fact would assuredly be well known in India, where "Flying Foxes," as they are termed, are so very abundant. Of one brought alive into France, it is indeed stated, that "during the voyage, on one occasion when its food ran short, it fastened upon adead fowl, and made ameal of part of it ;and from that time animal food was occasionally given to it :" but Idoubt much whether this was anatural appetite of the creature, from observation of one exhibited in England by Mr. Cross, of the Surrey Zoological Gardens, and puffed by him in advertisements and hand-bills as the wondrous "Fampyre." This animal would eat nothing but fruit and vegetables, and constantly refused insects, avariety of which Ioffered to it. It was tame, and appeared fond of being noticed. Hence Iam also inclined to doubt astatement which Ihave somewhere met with, to the effect that the little Kiodote is partly insectivorous, this animal being known with certainty to feed largely on the fruit of the Eugenia. 1842.] Megadermata and certain other Vespertilionida. 257 particular species of butterfly, inhabiting Cuba, is much preyed upon towards the evening by different species of Bats, adds "principally the Phillostoma Jamaicense [Arctibeus Jamaicensis, Leach]. By the way," remarks this observer, "in the 2d edition of the Regne Animal, the author says of the Phillostomes, 'Ce sont des animaux d'Amerique, qui ont l'habitude de sucer le sang des animaux ;' Ican only say that this is not only quite untrue as respects the Cuban species, but perfectly impossible [!] .The Ph. Jamaicense, for instance, lives on fruits and winged insects, in search of which latter it will be found in bed rooms. The Vampyre Bat of South America is also aPhyllostoma of Cuvier and Geoffroy ;but until some person having pretension to the name of naturalist shall establish the fact on personal observation, Ishall as readily believe that it sucks the blood of men as that the Caprimulgus sucks the milk of goats." — Trans. Zool. Soc, I, 187. This is rather asweeping denunciation of the detailed assertions of Condamine, Steedman, and ahost of others, though there is now every reason to conclude that Mr. McLeay is perfectly correct, so far at least as regards the Phyllostomata attacking large animals ;and concerning this genus, too, he mentions afact which is not generally known, stating that its members are partly frugivorous. The same is, however, also noticed by Mr. Swainson, who informs us, (Class. Quadrupeds, p. 94,) that "several of the Brazilian Bats are likewise frugivorous, and to such adegree, that we remember never having been able to secure a ripe fig from agarden we possessed at Pernambuco, and where many of these trees grew :nets, indeed, were spread over them, but the cunning animals seemed to have the instinct of mice ;they crept under the smallest opening, and completely baffled our endeavours to stop their plunderings." But this author also notices the sanguivorous habits of at least some South American species, mentioning that, "Our horses and mules, after having arrived at the end of aday's journey, and been turned out to graze, would be brought in by the guides in the morning with their shoulders covered with blood." To be brief, in all instances wherein the habits of the Phillostomata have been directly observed, the result has corresponded with the above statements. Mr. Waterton, for example, tells us, in his celebrated 'Wanderings,' "As there was afree entrance and exit to the Vampyre in the loft where Islept, Ihad many afine opportunity of paying atten- 258 Notice of the Sanguivorous habits of the [No. 123. tion to this nocturnal surgeon. He does not always live on blood. When the moon shone bright, and the fruit of the banana was ripe, I could see him approach and eat it. He would also bring into the loft, from the forest, agreen round fruit, something like the wild guava, and about the size of anutmeg. There was something, also, in the blossom of the suwarre nut tree, which was grateful to him ;for on coming up acreek, on amoonlight night, Isaw several Vampyres fluttering round the top of the suwarre trees, and every now and then the blossoms, which they had broken off, fell into the water. They certainly did not drop off naturally, for on examining several of them, they appeared quite fresh and blooming. So Iconcluded the Vampyres picked them from the tree, either to get at the incipient fruit, or to catch the insects which often take up their abode in flowers. "There are," according to Mr. Waterton, "two species of Vampyre in Guiana, alarger and asmaller. The larger sucks men and other [mammiferous] animals ;while the smaller seems to confine itself chiefly to birds. Ilearned from agentleman, high up the river Demarara, that he was completely unsuccessful with his fowls, on account of the small Vampyre. He shewed me some that had been sucked the night before, and they were scarcely able to walk." He then proceeds to give ahumorous account of his companion, aNorth Briton, who had been bitten by one of these creatures, and lay muttering imprecations on the whole race of them. "As soon as there was light enough," writes Mr. Waterton, "Iwent to his hammock, and saw it much stained with blood. 'There,' said he, thrusting his foot out of the hammock, 'see how these infernal imps have been drawing my life's blood.' On examining his foot, Ifound that the Vampyre had tapped his great toe :there was awound somewhat less than that made by aleech ;the blood was still oozing from it. Iconjectured he might have lost from 10 to 12 oz. of blood. "Ihad often wished," continues this observer, "to have been once stung by the Vampyre, in order that Imight have it in my power to say it had really happened to me. There can be no pain in the operation, for the patient is always asleep when the Vampyre is sucking him, and as for the loss of afew ounces of blood, that would be a trifle in the long run. Many anight have Islept with my foot out of the hammock, to tempt this winged surgeon, expecting that he 1842.] Megadermata and certain other Vespertilionidce. 259 would be there ;but it was all in vain ;the Vampyre never sucked me, and Icould never account for his not doing so, for we were inhabitants of the same loft for months together."—(pp. 174—9). The very obvious inference is, that the large Phyllostomata, which Mr. Waterton, in common with Steedman and the mass of other narrators of the doings of the Vampyre, have accused of this blood-sucking propensity, are totally innocent of the charge, as regards at least their attacking human beings or other large animals ;but that there does exist atrue Vampyre, capable of inflicting wounds such as described, which most assuredly the formidable canines of the Phillostomata are quite unfitted for, is equally evident from the above cited testimony alone. According to Condamine, "The Bats, which suck the blood of horses, mules, and even men, when they do not secure themselves from them by sleeping under atent, are anuisance, common to most of the hot countries of America, and some of them are of a monstrous bigness [?] :at Borja, and in divers other places, they have entirely destroyed the great cattle, which the Missionaries had introduced, and which had begun to multiply in those parts." In corroboration of this account, an accomplished modern traveller, Mr. Schomburgh, has assured me, that at Wicki, on the river Berbice, no fowls could be kept on account of the ravages of these creatures, which attacked their combs, causing these to appear white from loss of blood. Goats resisted them best, but even hogs were attacked by them. In the report of the Committee of the French Academy, upon the results of M. Alcide d'Orbigny's late expedition, published in the 'Nouvelles Annales du Museum,' III, 90, we are informed, that "Dans l'ordre des Carnassiers, M. d'Orbigny asurtout etudie les Vampyres, dont il apu confirmer les habitudes de sucer le sang des animaux, et meme de l'homme, et cela sur ces gens et sur les mulets de sa caravanne. L'avidite de ces animaux pour le sang est telle, que les naturels sont obligees pour ysoustraire de passer la nuit dans des moustiquaires, et de renfermer soigneusement leurs poules et autre animaux domestiques. Le Vampyre choisit, en general, la nuque, le cou, ou le dos de la victime, afin qu'elle puisse plus difncilement s'en d'ebarasser ;auqu'elle fait cepandant en se roulant sur le dos." Thus far we have still no satisfactory information as to what is the real depredator, for not only is there strong presumptive evidence that this cannot be the Phillostoma, as currently supposed, but the real habits of 260 Notice of the Sanguivorous habits of the [No. 123. this group, so far as positively observed, would appear to be solely frugivorous and insectivorous. To Mr. Charles Darwin we owe the solution of this mystery. "The Vampyre", writes this accomplished naturalist, "is often the cause of much trouble, by biting the horses on the 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, and Iwas therefore fortunate in being present when one was caught on ahorse'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 Vampyre. 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 effect. "Before the introduction of the domesticated quadrupeds," continues Mr. Darwin, "the Vampyre Bat probably preyed on the Guanaco, or Vicugna, for these, together with the Puma, and Man, were the only terrestrial mammalia of large size, which formerly inhabited the northern parts of Chili. This species must be unknown, or very rare, in Central Chili, since Molina, who lived in that part, says that no bloodsucking species is found in that province." The specimen here referred to, is now deposited in the Museum of the Zoological Society, and is referrible to the genus Desmodus of Prince Maximilian of Saxe Nieud, or Edostoma of d'Orbigny, differing very widely in its dental characters from Phillostoma, or indeed any other animal previously known. Its entire structure is expressly modified for the Vampyre'smode of subsistence. It has only two upper incisors, corresponding to the ordinary middle pair of the Primates generally, and which, ordinarily larger than the others, here attain their maximum of development to the exclusion of the latter: they are large, and of singular form, approximated, and occupy the whole space between the canines, are longitudinally bent abruptly inward near the median line, and prolonged and acutely pointed at the tip of the bend, being received into acavity or sheath behind the lower incisors when the mouth is closed, the under-jaw consequently projecting beyond the upper :together with analogousl ancetshaped canines, which are thinly compressed laterally ;they form an admirable instrument for blood-let- 1842.] Megadermata and certain other Vespertilionida. 261 ting, inflicting atriple puncture like that of aleech :the lower canines are small and not compressed, and there are four bilobate inferior incisors, the medial separated by awide interval. Instead of the sharply tuberculated molars of the Phyllostomes, and of that division in particular styled Vampyrus by systematists, there are even no true molars whatever, intimating that the accustomed food requires no mastication ; but there are two false molars immediately behind the canine in the upper-jaw, and three antagonizing with them in the lower, that present only keenly cutting edges, adapted for severing in the manner of apair of scissors. Nor is this all:—as in carnivorous animals, wherein the food is more readily assimilated, the intestines are consequently less prolonged than in vegetable -feeders, so in the present most remarkable genus, where blood—warm from the living veins, and even quickened by the vital principle,—constitutes the aliment, the intestines (as Ihave been informed) proceed almost straight to the anus. In short, we have here an animal duly organized for the mode of life so often described, which the Phillostomata are not ;and there can scarcely be adoubt that numerous species of Desmodus exist in tropical America, being everywhere the veritable Vampyres which attack man and other large animals, as ageneral rule during their sleep, and inflicting wounds so gently with their keenly pointed and lancet-like instruments of incision, that no sense of pain follows to awake their victim. Nevertheless, admitting the great probability of this, there still remain some matters for further explanation, to which my discovery of the predatory habits of the Megaderma seems to afford akey. Among the South American Vespertilionidce having teeth of the ordinary conformation, Professor Bell describes the tongue of the Phyllostomata to have "anumber of wart-like elevations, so arranged as to form acomplete circular suctorial disc, when they are brought into contact at their sides, which is done by means of aset of muscular fibres, having atendon attached to each of these warts."* Now, for what purpose can this be ?For drawing forth the juices of fruits ? Isuspect not :and Spix, it may be remarked, expressly designates his Glossophaga amplexicaudata, (which, however, presents another modification of the tongue, this being slender and elongate, and furnished with hair-like papillae,) Sanguisuga crudelissima, avery cruel bloodsucker; an expression which would seem to imply habits analogous *Dr. Todd's Cycl. Anat. and Phys., Art. Cheiroptera. 2M 2G2 Notice of the Sanguivorous habits of the Megadermata $c. [No. 123. to those of the Megaderms ;for these bite away at their victim in savage earnest, while drawing the life-blood from its veins. In short, there are two classes of blood -sucking Bats,—one gentle and insidious, which attack any large animal during its sleep, are expressly organized for this purpose, and doubtless derive their whole sustenance in this way, — and another openly rapacious, which ferociously attack (it may be presumed) any small warm-blooded creature that they can master, and more especially, it is probable, prey on the smaller and weaker members of their own tribe, first drawing their blood, and then devouring them, as instanced by the oriental Megaderms ;and to this latter class, Iimagine, many of the large leaf-nosed Bats of South America appertain (though also known to feed both on fruit and insects), and probably also at least the larger Rhinolophi* With regard to the Megaderma lyra, Iam of opinion (founded on further observation of the captive animal), that it is in no degree whatever frugivorous, and the structure of its mouth would imply that it is no insect-hunter ;neither do Ithink it evinces any disposition to attack small birds, either at roost or moving :but I am led to infer that the smaller Vespertilionidce constitute its main, if not sole, subsistence, and suspect that these are seized while on the wing, and carried off to be devoured at leisure in some quiet recess, the preyer meanwhile sucking the vital fluid from the neck of its victim. There is more energy about it than Ihave observed in any other kind of Bat, at least during the day :go when you will, it is always lively and on the alert ;and the expression of its physiognomy is far from dull, having comparatively large eyes for aBat, which are bright and prominent. The species does not appear to be rare about Calcutta. Imay further remark, that the inguinal teats are well developed in this genus, as in the Rhinolophi ;equally so, indeed, with the pectoral teats, insomuch that no one who examined them could suppose that they are mere sebaceous glands, as suggested by Prof. Bell in the case of the Rhinolophi. This fact is not uninteresting with relation to the described position of the teats in the genus Cheiromys. *The tongue of the Megaderms presents nothing remarkable in its conformation; but the lips are, in this instance, expressly modified for suction, which is not the case in Phyllostoma. It is not unlikely that the West Indian genus Mormoops, of Leach, is another raptorial form.