The Common vampire bat is a small, leaf-nosed bat native to Latin America. It is short-haired, with silver-gray fur on its undersides, demarcated from the darker fur on its back. A well-developed, clawed thumb on each wing is used to climb onto prey and to assist the animal in take-off. The Common vampire bat practices hematophagy, mainly feeding on the blood of livestock. The bat usually approaches its prey at night while they are sleeping. It then uses its razor-sharp teeth to cut open the skin of its hosts and lap up their blood with its long tongue. Because it feeds on livestock and is a carrier of rabies, the Common vampire bat is considered a pest.
Common vampire bats are found in parts of Mexico, Central America, and South America. They prefer warm and humid climates and use tropical and subtropical woodlands and open grasslands for foraging. Bats roost in trees, caves, abandoned buildings, old wells, and mines.
Vampire bats live in colonies and have a number of cooperative behaviors such as social grooming and food sharing. Colony numbers can range from single digits to hundreds in roosting sites. The basic social structure of roosting bats is made of female groups and their offspring, a few adult males, known as "resident males", and a separate group of males, known as "nonresident males". Common vampire bats will also roost with about 45 other bat species and are usually the most dominant at roosting sites. They occupy the darkest and highest places in the roosts; when they leave, other bat species move in to take over these vacated spots. Vampire bats hunt at night, using echolocation and olfaction to track down prey. They feed in a distance of 5 to 8 km (3.1 to 5.0 mi) from their roosts. When a bat selects a target, it lands on it, or jumps up onto it from the ground, usually targeting the rump, flank, or neck of its prey; heat sensors in the nose help it to detect blood vessels near the surface of the skin. It pierces the animal's skin with its teeth, biting away a small flap, and laps up the blood with its tongue, which has lateral grooves adapted to this purpose. Common vampire bats are protective of their host and will fend off other bats while feeding and only mothers and their offspring may feed on the same host.
Common vampire bats are carnivores and feed primarily on mammalian blood, particularly that of livestock such as cattle and horses. They feed on wild prey like the tapir but seem to prefer domesticated animals, and favor horses over cattle when given the choice.
Common vampire bats are highly polygynous, and dominant adult males defend groups of females. They may breed year-round, although the number of births peaks in the rainy season. Females give birth to one offspring per pregnancy, following a gestation period of about 7 months. The young are raised primarily by females. Mothers leave their young to hunt and call their young to feed upon returning. The young accompany their mothers to hunt at 6 months but are not fully weaned until 9 months. Female offspring usually remain in their natal groups into adulthood, unless their mothers die or move. The occasional movements of unrelated females between groups lead to the formation of multiple matrilines within groups. Male offspring tend to live in their natal groups until they are 1 to 2 years old, sometimes being forced out by the resident adult males. Common vampire bats reach reproductive maturity when they are 9-10 months old.
There are no major threats facing Common vampire bats at present.
According to IUCN, the Common vampire bat is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.