Vampire bats use infrared sensors to detect veins on their warm-blooded prey, according to new research.
In a study published in the journal Nature, the researchers found that vampire bats have evolved specialised heat-sensitive nerve channels around the nose. These allow the bats to home in on “hot spots” on their prey, where veins run close to the surface of the skin.
In other animals, including humans, these nerve channels are used to detect heat that would be damaging to the body, triggering a painful, burning sensation at temperatures above 43ºC. However, in the vampire bat the channels around the nose have evolved to activate at a much cooler 30ºC, allowing the bat to detect the body heat of its prey.
Found in Central and South America, the vampire bat is a widely feared species that has been commonly misportrayed as a creepy, blood-sucking killer. However, this small mammal rarely kills its prey and displays many fascinating adaptations to its lifestyle.
Its teeth are razor sharp, meaning its victim rarely notices being bitten, and it releases chemicals into the wound which keep the blood flowing, allowing the bat to lap it up with the help of grooves on its tongue.
The vampire bat also has strong limbs and an elongated thumb to help it climb around on its prey and take off after feeding. It rarely bites humans, usually preferring to feed on the blood of birds and other mammals, particularly livestock. Vampire bats also show a rare form of ‘reciprocal altruism’, in which well-fed individuals regurgitate food to hungry companions, even if they are not related.
Rare heat-sensing ability
Only three other vertebrate groups are known to have a heat-detecting ‘sixth sense’ – the distantly related pitvipers, pythons and boas. These three snake lineages use specialised structures on the face, known as ‘pit organs’, to detect warm-blooded prey. However, they use a different mechanism to the vampire bat.
The ability to find its next meal is especially important to the vampire bat as it must have a blood meal at least once every few days to survive.
In addition to revealing more about the bat’s intriguing adaptations, the researchers hope that this study will help shed more light on how heat sensors work in humans. It may even help scientists to design drugs to suppress the activity of related nerve channels, such as those involved in inflammatory pain.
Read more about the study at Nature News – Vampire bats turn down the heat sensors to hunt.
Liz Shaw, ARKive Species Text Author