Common Vampire Bats (Desmodus rotundus) are in the Kingdom Animalia, Phylum Chordata, Subphylum Vertebrata, Class Mammalia, Order Chiroptera, Family Phyllostomidae, Subfamily Desmodontinae, Species Desmodus rotundus. [1] Desmodus Rotundus is put in the Phyllostomidae family but some scientists feel that they should be classified in their own family, so sometimes textbooks categorize them as Desmodontinae. [2]

            Vampire bats are known to have roamed this world about 6-8 million years ago. From fossil records, we can conclude that long ago there used to be more species of vampire bats, but as of now, there are only three, desmodus rotundus being the most common. [3] Desmodus Rotundus live in Northern Mexico, Central Chile, Argentina and Uruguay as well as on the islands of Margarita and Trinidad off northern Venezuela, also known as the New World. They can only survive in warm climate, whether it be dry or humid, and are usually found in tropics and subtropics. Desmodus rotundus usually dwell in lodgings such as caves, mines, tree hollows and occasionally abandoned buildings. As for their conservation status, common vampire bats are not endangered population; in fact their numbers have increased because of more livestock in South America.[4]

Desmodus rotundus is distinguished from the other true vampire bats by its pointed ears, longer thumb with a distinct basal pad, naked interfemoral membrane, and dental features. This genus has only 20 teeth, the largest being the 2 chisel-like upper incisors and the 2 upper canines.The common vampire bat has grayish-brown fur which has lighter underparts. The wing span averages 350-400mm and the head and body length is usually 70-90mm. Adults usually weigh from 15-50 grams. Desmodus rotundus has no tail and the membrane between the hind legs, called the uropatagium, is reduced. Females are usually larger than males.[5]

Common vampire bats feed only on the blood of living animals, making them the only true parasites among mammals. [6] They usually feed in the early evening, after selecting an animal to feed on, it flies low and straight. It lands on the ground nearby, walking toward its victim and climbing up its leg.[7] The bat bites into their preyıs flesh with razor-sharp teeth. Two lateral grooves in the tongue expand and contract as the bat feeds.[8] Contrary to popular belief, the common vampire bat does not ³suck² the blood of its victim, rather, it laps up the blood as it drips out of the neat incision. They feed on blood from cows, pigs, horses, and birds. Vampire bats rarely bite humans for blood . Since these bats do not chew their food, they have fewer teeth than other bats. In just half an hour, the nocturnal mammal can drink up to 80 per cent of its own body weight in blood - the equivalent of an average-sized person downing 100 pints in 30 minutes.[9] To survive, the vampire bat needs at least 2 teaspoons of blood a day. If it goes two nights without food, the desmodus rotundus will starve to death.[10]

Of all the bat species, only the desmodus rotundus can maneuver on the ground as well as they do in the air, they are capable of walking on all fours with the body lifted off the ground; this is how they approach their sleeping prey. [11] They are capable of complex terrestrial movements that include flight-initiating vertical jumps. These terrestrial movements are essential for stalking and attacking their prey. This ability is associated with its feeding methods. Because of this unique behavior, the wing is constructed to allow both powered flights and generation of violent jumps.[12] Desmodus rotundus can walk, run, and hop quadrupedally along the ground. The weight of the bat is supported by the strong hind limbs and modified thumbs. When faster accelerations are necessary, hopping and jumping are preferred. [13]

            Records suggest that Desmodus rotundus breed all year-round. Some females have a postpartum estrus and produce more than one litter per year. Although young can be born at anytime during the year, there are peak months in which birth is more common, such as April and may and October and Novermber.[14] There normally is a single young; but sometimes twins are born. Recorded gestation periods of captive females are 205, 213, and 214 days. The young are well developed at birth, weighing between 5-7 grams, and their eyes are open.[15] For the first month, they are only able to feed on their motherıs milk, upon their second month of like they feed on regurgitated blood, at four months they are capable of accompanying their mothers on hunts. They are not completely weaned before 9-10 months. Sexual maturity seems to come at about the same time. These vampire bats live up to at least 12 years old. [16]

            One of the most interesting adaptations in demodus rotundus is in its saliva. The saliva of vampire bats contain three active ingredients to keep the blood flowing, allowing them to eat. The main ingredient prevents the blood from changing from a fluid state to a solid state, which is called anticoagulant. There is also a chemical that keeps the red blood cells from sticking together. The last ingredient prevents the veins under a wound to constrict. There has been a drug developed from research on the anticoagulant in vampire bat's saliva called Draculin, which is used to treat heart patients.[17]

            It was just recently discovered that the blood-clotting prevention abilities of the desmodus rotundus might be able to help heart attack/stroke patients and those who have their arteries obstructed. It is believed that these bats have potential in restoring blood flow because of the powerful blood thinning chemical they secrete to prevent clots forming and thus ensure the blood keeps flowing. The same chemical can also dissolve clots once formed.[18] More importantly, the substance, known as desmodus rotundus salivary plasminogen activator, or DSPA, may have an important advantage over the only available clot-busting stroke drug, tissue plasminogen activator, or t-PA. If carried out quickly, usually within three hours, t-Pa could minimize the harmful effects of a stroke. Studies now are testing up to nine hours for this procedure because most patients cannot get to the hospital in that short period of time and be tested for being good candidates in jus three hours. "If there are less bleeding complications, that's huge," said Diane Book, an assistant professor of neurology and a stroke specialist at the Medical College of Wisconsin.[19]



[1] Mulheisen, M. and R. Anderson. 2001. "Desmodus rotundus" (On-line), Animal Diversity Web. Accessed February 22, 2004 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Desmodus_rotundus.html.

[2] Tomlinson, D. "Natural History of the Vampire" (On-line). Accessed February 22, 2004 at http://www.batconservation.org/content/meetourbats/vampire.htm.

[3] Tomlinson, D. "Natural History of the Vampire" (On-line). Accessed February 22, 2004 at http://www.batconservation.org/content/meetourbats/vampire.htm

[4] Mulheisen, M. and R. Anderson. 2001. "Desmodus rotundus" (On-line), Animal Diversity Web. Accessed February 22, 2004 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Desmodus_rotundus.html.

 

[5] ³common vampire bat² Walkerıs Mammals of the World, John Hopkins University Press Copyright 1997 http://www.press.jhu.edu/books/walkers_mammals_of_the_world/chiroptera/chiroptera.phyllostomidae.desmodus.html

[6] ³vampire bat² Columbia Encyclopedia   http://search.epnet.com/direct.asp?an=IXBvampireb&db=aph

[7] Lisa Carattini, 2002 by PageWise, Inc http://va.essortment.com/batvampiredesm_rggj.htm

[8] Copyright 2003 Chicago Sun-Times, Inc.  January 10, 2003 Friday

[9] James Rampton, The Independent (London), October 30, 2003

[10] Tomlinson, D. "Natural History of the Vampire" (On-line). Accessed February 22, 2004 at http://www.batconservation.org/content/meetourbats/vampire.htm.

[11] ³vampire bat² www.encyclopedia.com

[12] Schutt, William, The Journal of Experimental Biology, September 15, 1997 http://jeb.biologists.org/cgi/reprint/200/23/3003.pdf

[13] Mulheisen, M. and R. Anderson. 2001. "Desmodus rotundus" (On-line), Animal Diversity Web. Accessed February 22, 2004 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Desmodus_rotundus.html.

[14] Mulheisen, M. and R. Anderson. 2001. "Desmodus rotundus" (On-line), Animal Diversity Web. Accessed February 22, 2004 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Desmodus_rotundus.html.

[15] ³common vampire bat² Walkerıs Mammals of the World, John Hopkins University Press Copyright 1997 http://www.press.jhu.edu/books/walkers_mammals_of_the_world/chiroptera/chiroptera.phyllostomidae.desmodus.html

[16] Mulheisen, M. and R. Anderson. 2001. "Desmodus rotundus" (On-line), Animal Diversity Web. Accessed February 22, 2004 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Desmodus_rotundus.html.

 

[17] Tomlinson, D. "Natural History of the Vampire" (On-line). Accessed February 22, 2004 at http://www.batconservation.org/content/meetourbats/vampire.htm.

[18] James Le Fanu, The Daily Telegraph (London), January 14, 2003
http://web.lexisnexis.com/universe/document?_m=ca94b7231362fb7ff938ee16b7199344&_docnum=2&wchp=dGLbVlz-zSkVb&_md5=46df34f5a0285894c56fab1ea45e6bac

[19] John Fauber, Milwaukee Journal Sentinel (Wisconsin), January 10, 2003 Friday FINAL EDITION
http://web.lexisnexis.com/universe/document?_m=ef529251379fbea45f15607a02b848e9&_docnum=1&wchp=dGLbVlz-zSkVb&_md5=b6cf5652d3a324d3a6130ec77b168ae9