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.