Common Vampire Bat

Lore & Background

Vampire bats live in colonies in almost completely dark places, such as caves, old wells, hollow trees, and buildings. The basic social structure consists of female groups and their offspring, a few adult males known as 'resident males', and a separate group of males known as 'nonresident males'. Resident males mate with the females in their harems, and it is less common for outside males to copulate with the females. Female offspring often remain in their natal groups, and several matrilines can be found in a group as unrelated females regularly join. Male offspring tend to live in their natal groups until about two years old, sometimes being forcibly expelled by resident adult males. Vampire bats on average live about nine years in the wild.

In Their Own Story

A vampire bat can only survive about two days without feeding, yet cannot be guaranteed of finding food every night. When a bat fails to find food, it will often 'beg' another bat for food. A 'donor' bat may regurgitate a small amount of blood to sustain the other member of the colony. For equally familiar bats, the predictive capacity of reciprocity surpasses that of relatedness. Donor bats were more likely to approach starving bats and initiate the food sharing. When individuals of a population are lost, bats with a larger number of mutual donors tend to offset their own energetic costs at a higher rate than bats that fed less of the colony before the removal. Individuals that spend their own energy as a social investment are more likely to thrive, and higher rates of survival incentivize the behavior and reinforce the importance of large social networks in colonies.

Reader's Guide

The common vampire bat feeds primarily on the blood of mammals (occasionally including humans). It hunts only when it is fully dark, emitting only low-energy sound pulses. Once it locates a host, such as a sleeping mammal, it lands and approaches on the ground while on all fours. It then likely uses thermoception to identify a warm spot on the skin to bite. It starts to lick the area repeatedly to make the place tender so that it is easier to bite. It then creates a small incision with its teeth and laps up blood from the wound. When feeding on sleeping humans, they typically target exposed areas of the body, such as the toes, nose and ears. The common vampire bat has specialized thermoreceptors on its nose, which aid in locating areas of its prey where blood flows close to the skin. A nucleus has been found in its brain with similar position and histology to the infrared receptor of infrared-sensing snakes. A recent study showed that common vampire bats tune a TRP-channel that is already heat-sensitive, TRPV1, by lowering its thermal activation threshold to about 30 °C (86 °F).

Did You Know?

• The common vampire bat has specialized thermoreceptors on its nose that help locate areas where blood flows close to the skin.
• A nucleus in the vampire bat's brain has a similar position and histology to the infrared receptor of infrared-sensing snakes.
• Vampire bats can walk, jump, and even run using a unique bounding gait where the forelimbs are recruited for force production.
• The common vampire bat's loss of the REP15 gene allows for enhanced iron secretion in adaptation to the high iron diet.
• Vampire bats have a high level of resistance to a group of bloodborne viruses known as endogenous retroviruses.