Vampire bat: what you need to know



by LORENZO CIOTTI

Vampire bat: what you need to know

Vampire bat is spread from the eastern Mexican states of Tamaulipas and western Sonora across Central and South America to northern Argentina and Chile. It is also present on the island of Trinidad and Isla Margarita. It forms colonies between 20 and 100 individuals, although even more numerous colonies of up to 5,000 individuals have been observed.

He takes refuge in illuminated caves with deep cracks and sometimes even in tree cavities. They have also been observed in ruins, mines and abandoned buildings. In resting sites, an ammonia smell is common due to the presence of digested and regurgitated blood on the ground or on the walls.

Males compete with each other in shelters where females are present. Defensive actions usually include chases, pushes, threats, wing attacks and bites. It becomes most active two hours after sunset. It has long wings and is a fast flier but also very agile on the ground.

The long thumbs and large feet allow them to walk, run and jump with great dexterity. When confined to spaces where it cannot take flight, it makes impressive leaps to escape capture.

Vampire bat: what you need to know

A particular cooperative behavior is present in this species, known as reciprocal altruism, in which females, and sometimes even males, regurgitate the blood previously taken from their prey to give to their own young or to other members of the colony who have not been able to obtain it, particularly about a third of the younger specimens, which are more frequently discovered by their victims due to their inexperience.

Subsequent experiments in captivity indicated that Azara's true vampire not only identifies and feeds preferably members of her own colony or family group but more easily helps those specimens who had previously offered her food.

This particular type of aid is of considerable importance in the survival of some populations, since a specimen that is unable to feed for at least three consecutive days is destined to die. It feeds exclusively on the blood of other vertebrates, in particular of domestic animals, taken through the bites inflicted with the very sharp incisors and avoiding its coagulation through an anticoagulant glycoprotein known as draculin, contained in its own saliva.

In captivity it also attacks snakes, lizards, toads, crocodiles and turtles. His movements are agile and stealthy. It usually does not land directly on the victim, but in the vicinity of it, and then walks or hops towards it. Several individuals can feed from the same wound successively.