Vampire bat

Vampire bats are bats whose food source is blood, a dietary trait called hematophagy. Three bat species feed solely on blood: the common vampire bat (Desmodus rotundus), the hairy-legged vampire bat (Diphylla ecaudata), and the white-winged vampire bat (Diaemus youngi). All three species are native to the Americas, ranging from Mexico to Brazil, Chile, and Argentina.

Species

Due to differences among the three species, each has been placed within a different genus, each consisting of one species. In the older literature, these three genera were placed within a family of their own, Desmodontidae, but taxonomists have now grouped them as a subfamily, the Desmodontinae, in the leaf-nosed bat family, Phyllostomidae.

The three known species of vampire bats all seem more similar to one another than to any other species. That suggests that sanguivorous habits (feeding on blood) evolved only once, and the three species share a common ancestor.

Anatomy and physiology

Unlike fruit-eating bats, the vampire bats have short, conical muzzles. It also lacks a nose leaf, instead having naked pads with U-shaped grooves at the tip. The common vampire bat, Desmodus rotundus, also has specialized thermoreceptors on its nose, which aid the animal in locating areas where the blood flows close to the skin of its prey. A nucleus has been found in the brain of vampire bats that has a similar position and similar histology to the infrared receptor of infrared-sensing snakes.