Rainforest Vampire Bats
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Vampire bats (Desmodus rotundus) are bats that feed on blood. This particular habit in certain animals is known as 'hematophagy'.
There are only three bat species that actually feed on blood: The Common Vampire Bat (Desmodus rotundus) pictured left, the Hairy-legged Vampire Bat (Diphylla ecaudata) and the White-winged Vampire Bat (Diaemus youngi). All three species are native to the Rainforests of America, ranging from Mexico to Brazil, Chile, and Argentina.
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Vampire bats very rarely bite people because they apparently dislike human blood. The three species of Bats are quite different from each other and are therefore placed within different genera (no other species are currently classified in any of the three genera concerned). But they are related.
Rainforest Bat Characteristics
Vampire bats have burnt amber coloured fur on their backside while soft and velvety light brown fur that covers their belly. Vampire bats have a wingspan of about eight inches and a body about the size of an adult's thumb.
Unlike fruit-eating bats, the vampire bats have a short, conical muzzle without a nose leaf. Instead they have naked pads with U-shaped grooves at the tip. The common vampire bat also has specialised infrared sensors on its nose, by which it perceives temperature. A nucleus has been found in the brain of vampire bats that has a similar position and has similar histology to the infrared nucleus of infrared sensitive snakes.
Vampire bats have small ears and a short tail membrane. Their front teeth are specialised for cutting and their back teeth are much smaller than in other bats. Their digestive systems are also specialised for their liquid diet. The saliva of vampire bats contains the substance, 'draculin', which prevents the victim's blood from clotting. Vampire bats therefore, lap blood rather than suck it as most people imagine.
Rainforest Bat Diet
Vampire Bats only come out to feed when it is fully dark. Like fruit-eating bats and unlike insectivorous and fish-eating bats, they only emit low-energy sound pulses. The Common Vampire Bat feeds mostly on the blood of mammals, whereas the Hairy-legged Vampire Bat, and the White-winged Vampire Bat feed on the blood of birds.
Once the common vampire bat locates a host, usually a sleeping mammal, they land and approach it on the ground. A recent study found that common vampire bats can, in addition to walking, run at speeds of up to 1.2 metres per second. Vampire bats locate a suitable place to bite their victims using their infrared sensors.
The feeding pattern of the vampire bat adds a layer of complexity to its anatomy. Because they often do not find host organisms for many hours and may have to fly a long distance to do so, vampire bats usually feed in enormous quantities. This influx of proteins can however make the bat too heavy to fly. Vampire bats have so much stealth that they can drink for 30 minutes without awakening the animal. If vampire bats do not get blood for two days, they will eventually die, but that is less likely to happen. Female bats are generous and will give their blood to other bats who lack food.
Apparently, the bat's urinary system accommodates this by releasing dilute urine consisting of a lot of water and fewer solutes. However, when the bat is resting, a new problem is faced. The large amounts of protein create excess urea and must be disposed of. The urinary system of the vampire bat then uses various hormones to make concentrated urine which consists of more urea and less water.
Rainforest Bat Habitats
Vampire bats tend to live in almost completely dark places, such as caves, old wells, hollow trees and buildings. Colonies can range from a single individual to thousands. Vampire bats often roost with other species of bat.
Rainforest Bat Reproduction
Common vampire bats will almost always have only one offspring per breeding season. Each colony will typically contain only one reproducing male, with around twenty females and their offspring. Vampire bats need blood at least once every few days to survive. If they cannot get blood, they will approach another vampire bat whilst roosting, asking for a blood 'transfusion'. The blood is exchanged mouth-to-mouth in a motion that looks very much like kissing. Their babies use tiny thumbs in the middle of the wing to cling on the mother’s furry belly.
Rainforest Bat Lifespan
Vampire bats can live up to 9 years in the wild and up to 19 in captivity.
Rainforest Bat Conservation Status
Vampire bats are not an endangered species and have a conservation status of being 'Least Concern'.
