Vampire bats are bats whose source of food is blood, a feature of a diet called hematophagy. Three bat species only eat blood: common vampire bats (Desmodus rotundus bats), vampire feather bats (Diphylla ecaudata bats), and white winged vampire bats (< i> Diaemus youngi ). The three species are from America, from Mexico to Brazil, Chile, Uruguay and Argentina.
Video Vampire bat
Taxonomy
Because of the differences between the three species, each has been placed in a different genus, each composed of one species. In older literature these three genera are placed in a family of their own, Desmodontidae, but taxonomists now classify them as subfamilies, Desmodontinae, in the family of leaf-nosed bats, Phyllostomidae.
Three known species of vampire bats all look more like each other than other species. It shows that hematophagy (feeding on blood) evolved only once, and three species have the same ancestor.
Evolution
Vampire bats are in a diverse family of bats with many sources of food, including nectar, pollen, insects, fruits, fish, and meat. Three species of vampire bats are the only mammals that have evolved to feed exclusively on blood (hematophagy) as micropredators, a strategy in parasitism. Haematophagy is rare due to the number of challenges that must be overcome to succeed: large volumes of fluids potentially crippled the kidneys and bladder, the risk of iron poisoning, and overcame the excess protein. There are several hypotheses for how vampire bats evolved.
- They evolved from fruit-eating bats with special sharp teeth to pierce fruit
- Initially they were fed ectoparasites from large mammals, and then thrived to feed on the mammals themselves (similar to the eating behavior of red cobs)
- They initially eat insects that are attracted to animal wounds, and then thrive to feed on wounds
- They initially prey on small arboreal vertebrates
- They are arboreal omnivores themselves and start swallowing blood and flesh from the wound location of larger animals
- They are special nectar feeders that evolved to feed other types of liquids
The lineage of vampire bat deviates from his family 26 million years ago. Hairy vampire bats may deviate from two other vampire bat species 21.7 million years ago. Because the vampire bats are fur-legged in birds 'blood and it is an ancestor vampire bat, it is likely that all vampire bats were originally fed by birds' blood. Recent analysis shows that vampire bats arise from insectivores, which reduce the original frugivores, carnivores, and nectarivore hypotheses. Within 4 million years of deviation from other Phyllostomids, vampire bats have evolved all the adaptations necessary for blood feeding, making it one of the quickest examples of natural selection among mammals.
Maps Vampire bat
Anatomy and physiology
Unlike fruit bats, vampire bats have short snouts and cones. It also has no nose leaves, instead of having a bare cushion with a U-shaped groove at the end. The common vampire bat, Desmodus rotundus , also has a special thermoreptor in its nose, which helps the animal find an area where blood flows close to the skin of its prey. A nucleus has been found in the brain of vampire bats that have similar position and histology similar to infrared receptors from infrared sensing snakes.
Vampire bats have special front teeth for cutting and the back teeth are much smaller than in other bats. The inferior colliculus, part of the bat brain that processes sound, adapts well to detect the regular breathing sounds of sleeping animals that serve as its main food source.
While other bats have almost lost the ability to maneuver on land, vampire bats can walk, jump, and even run by using a unique walking style, where the forefoot instead of the rear leg is recruited for forced production, because its wings are much larger. stronger than the feet. The ability to run this seems to have evolved independently in the bat lineage.
Vampire bats use infrared radiation to find blood spots on their prey. A recent study has shown that common vampire bats set the TRPV1 heat-sensitive TRP channel by lowering the thermal activation threshold to about 30 ° C. This is achieved through alternate splicing of TRPV1 transcripts to produce channels with terminally cut-carunced cytoplasmic domains. This splicing event occurs exclusively in the trigeminal ganglia, rather than the dorsal root ganglia, thus retaining the role for TRPV1 as a dangerous heat detector in somatic afferent. The only other vertebrates capable of detecting infrared radiation are the boas, pitons and pit vipers, all of which have pit organs.
Ecology and life cycle
Vampire bats tend to live in colonies in almost dark places, such as caves, old wells, hollow trees, and buildings. They range from Central to South America and live in dry, tropical and subtropical regions. The number of vampire bat colonies can range from one digit to hundreds on roosting sites. The basic social structures of the eating bats are made up of groups of women and their descendants, some adult males, known as "male population", and separate male groups, known as "nonresident men". In furry vampire bats, the non-resident hierarchical segregation of non-resident males appears less restrictive than the common vampire bats. Non-resident males are accepted into the harem when ambient temperature decreases. This behavior shows social thermoregulation.
Men live married to females in their harems, and it is less common for outer men to copulate with females. Girls are often in their birth cohorts. Some matrilines can be found in groups, as unrelated women regularly join groups. Boys tend to live in their christmas group until they are about two years old, sometimes forced to be excluded by adult male residents.
Vampire bats form strong bonds with other colony members. The unique adaptation of vampire bats is the sharing of food. A vampire bats can last only about two days without eating blood, but they can not be guaranteed to find food every night. This poses a problem, so when a bat fails to find food, it will often "beg" other bats for food. A "donor" can spew out a little blood to support other colony members. For an equally intimate bat, the reciprocal predictive capacity goes beyond that. These findings suggest that vampire bats are able to preferably assist their families, but that they can benefit more from forming cooperative reciprocal relationships with relatives and non-relatives. Furthermore, donor bats tend to approach the starving bats and begin the distribution of food. This finding is contrary to the harassment hypothesis - which claims that individuals share food to limit harassment by invoking individuals. All that considered, the study of vampire bats should be interpreted with caution because there is much correlational evidence and still requires further testing.
Another ability possessed by some vampire bats is to identify and monitor the positions of individuals (individuals of the same species) simply by antiphonal calls.
Vampire bats are also involved in social care. It usually occurs between females and offspring, but is also significant among adult females. Social care is mostly related to the distribution of food.
Giving Feeding
Vampire bats hunt only when it's completely dark. Like fruit-eating bats, and unlike insectivorous and eating fish bats, they only release low energy energy pulses. Common vampire bats mainly feed on mammalian blood (sometimes including humans), whereas vampire-haired bats and white-winged bat vampires primarily feed on birds' blood. After a common vampire bat finds the host, like a sleeping mammal, he lands and approaches him on the ground. Then the possibility of using thermoception to identify the warm spot on the skin to bite. They then make small incisions with their teeth and drink blood from the wound.
As noted by Arthur M. Greenhall:
If there are feathers on the skin of the host, the common vampire bats use canine teeth and their cheeks are like razors to shave feathers. The sharp and sharp incisors of the bat's top teeth make 7mm wide and 8mm pieces. The upper incisors do not have enamel, which makes them sharply permanent. Their teeth are very sharp, even handling their skulls in the museum can result in injuries.
Bat saliva, remaining in the victim's bite wound, has a key function in the feeding of the wound. Saliva contains some compounds that extend bleeding, such as anticoagulants that block blood clotting, and compounds that prevent the constriction of blood vessels near the wound.
Digestion
A typical female vampire bats weigh 40 grams and can consume more than 20 grams (1 ounce of fluid) of blood in 20 minutes. This eating behavior is facilitated by anatomy and physiology for the rapid process and blood digestion to allow animals to fly immediately after breastfeeding. The gastric layer quickly absorbs the blood plasma, which is rapidly transported to the kidneys, and to the bladder for excretion. Common vampire bats start removing urine within two minutes of eating. While spilling a lot of blood fluid facilitates flight takeoff, the bat has still added nearly 20-30% of its body weight in the blood. To take off from the ground, bats generate extra lift power by squatting and throwing themselves into the air. Usually, within two hours of searching for food, the common vampire bats return to their cages and settle to spend the rest of the night digesting their food. Digestion is aided by their microbiome and their genome protects them against pathogens in the blood.
Human health
Although rare, human infection by rabies from the bats of vampire bats has been documented; for example in 2010 four children in Peru died after being bitten. The highest occurrence of rabies in vampire bats occurs in large populations found in South America. However, the risk of infection in the human population is less than the livestock exposed to bat bites. Only 0.5% of bats carry rabies, and those who may be clumsy, lose their way, and can not fly.
The unique nature of the saliva of vampire bats has found some positive use in treatment. A study in the January 10, 2003 edition of Stroke: The Journal of the American Heart Association tested a genetically engineered drug called desmoteplase, which uses the anticoagulant properties of saliva Desmodus rotundus , and proven to increase flow blood in stroke patients.
See also
- spectral bat ( Vampyrum spectrum ), also called fake vampire bats - the world's largest carnivorous bats weighing 145-190 g and wingspan 60 to 90 cm
- Vampires
Footnote
Further reading
- Greenhall, Arthur M. 1961. Bats on Agriculture . Publication of Ministry of Agriculture. Trinidad and Tobago.
- Greenhall, Arthur M. 1965.
Eating Habits of the Trinidad's Brain Vampire . - Greenhall, A., G. Joermann, U. Schmidt, M. Seidel. 1983. Mammalian species: Desmodus rotundus. American Society of Mammalogists, 202: 1-6.
- A.M. Greenhall and U. Schmidt, editors. 1988. History of Vampire Bats , CRC Press, Boca Raton, Florida. ISBNÃ, 0-8493-6750-6; ISBN 978-0-8493-6750-2
- Campbell A, Ride RR, Sowards L, Stone M (2002). "Biological and sensory biological imaging" (PDF) . Micron . 33 (2): 211-225. doi: 10.1016/S0968-4328 (01) 00010-5. PMID 11567889.
- Pawan, J.L. (1936b). "Rabies in the Vampire Bat of Trinidad with Special References to Clinical Courses and Latency of Infection." History of Tropical Medicine and Parasitology . Vol. 30, No. 4. December, 1936.
External links
- Blog research on vampire bats Web sites devoted to social behavior and cognition of vampire bats.
- Schutt, W.A., Jr. "Dark Banquet" Website devoted to the biology of blood-eating creatures.
- Bat World - Non-volunteer, non-salary, non-profit organization devoted to education, conservation and rehabilitation of bats
- Bat Conservation International Website devoted to education, conservation, and study of bats.
Source of the article : Wikipedia
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