Animal Diversity Web

Ge­o­graphic Range

The com­mon vam­pire bat is found from Mex­ico to Ar­gentina and Chile. (Turner, 1975)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

Habi­tat

Com­mon vam­pire bats are lim­ited to warm cli­mates. They can be found in both arid and humid parts of the trop­ics and sub­trop­ics. They occur up to 2400 me­ters in el­e­va­tion (Dr. A. Ramirez, Na­tional Co­or­di­na­tor Ra­bies Pro­gram, México, pers. comm.). The dis­tri­b­u­tion is thought to ap­prox­i­mate the ex­tent of the 10 de­gree min­i­mal isotherm for Jan­u­ary.

The bats usu­ally live in colonies rang­ing from 20 to 100 in­di­vid­u­als al­though much larger colonies (up to 5,000) have been re­ported. Desmodus ro­tun­dus roosts in mod­er­ately lighted caves with deep fis­sures, and in tree hol­lows. Vam­pire bats can also be found in old wells, mine shafts, and aban­doned build­ings. Roosts often smell strongly of am­mo­nia be­cause of the di­gested blood that has col­lected in the crevices and on the floors of the roosts. (Brass, 1994)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest
• scrub forest

• Other Habitat Features
• caves

• Range elevation

  2400 (high) m

  7874.02 (high) ft

Phys­i­cal De­scrip­tion

Desmodus ro­tun­dus has gray­ish-brown fur which is lighter on the ven­tral side. The muz­zle is com­pact and looks swollen, and the ears are pointy. The wing span av­er­ages 350-400mm and the head and body length is usu­ally 70-90mm. The com­mon vam­pire bat has no tail and the mem­brane be­tween the hind legs, called the uropatag­ium, is re­duced. Fe­males are usu­ally larger than males.

The com­mon vam­pire bat is highly adapted for its spe­cial­ized feed­ing be­hav­ior. The brain­case is large and the ros­trum is re­duced to ac­co­mo­date large ra­zor-sharp in­cisors and ca­nines. There are two lat­eral grooves in the tongue that ex­pand and con­tract as the bat feeds. Desmodus ro­tun­dus has an acute sense of smell and large eyes.

The limbs are also spe­cial­ized. The thumb of the wing is long and well de­vel­oped, and the hind legs are strong. (Al­tenbach, 1979; Brass, 1994; Mac­don­ald, 1984; Walker, 1975)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  15 to 50 g

  0.53 to 1.76 oz

• Range length

  70 to 90 mm

  2.76 to 3.54 in

• Range wingspan

  350 to 400 mm

  13.78 to 15.75 in

• Average basal metabolic rate

  0.194 W

  AnAge

Re­pro­duc­tion

Males com­pete for space in roost­ing places con­tain­ing fe­males. When more than one male oc­cu­pies a roost, each de­fends a small part of the roost from other males. Wilkin­son ob­served res­i­dent males in tree roosts ac­tively de­fend­ing their ter­ri­tory from other wan­der­ing males. De­fense often in­cludes chas­ing, push­ing, and fight­ing. Fight­ing con­sists of ges­tur­ing, strik­ing with the wings, and bit­ing.

Mat­ing be­hav­ior be­gins with a male climb­ing onto a fe­male's back, grasp­ing her folded wings with his wings, and hold­ing the back of her neck in his mouth. Cop­u­la­tion lasts three to four min­utes. (Wilkin­son, 1985; Wilkin­son, 1986)

• Mating System
• polygynous

Desmodus ro­tun­dus is be­lieved to be sex­u­ally ac­tive through­out the year. Al­though young may be born at any time dur­ing the year, peak times for births oc­curred dur­ing April and May and in Oc­to­ber and No­vem­ber. A higher num­ber of preg­nant fe­males were seen dur­ing the rainy sea­son in Mex­ico and Costa Rica. Most fe­males have one preg­nancy per year, but it is pos­si­ble to have more than one preg­nancy in a year. The ges­ta­tion pe­riod is about seven months. Usu­ally only a sin­gle young is born, but oc­ca­sion­ally there are twins. The new­borns are well de­vel­oped and weigh be­tween five and seven grams at birth. For the first month, the young feed strictly on the mother's milk. Their weight dou­bles dur­ing this time. The young are in­tro­duced to blood meals by re­ceiv­ing re­gur­gi­tated blood from the mother dur­ing the sec­ond month of life and they ac­com­pany their moth­ers on hunts when they are four months old. The rapid growth is com­plete in five months. (Lord, 1992; Turner, 1975)

• Key Reproductive Features
• iteroparous
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous

• Breeding interval

  Most female vampire bats give birth to one young each year.

• Breeding season

  lthough young may be born at any time during the year, peak times for births occurred during April and May and in October and November.

• Range number of offspring

  2 (high)

• Average number of offspring

  1

• Average number of offspring

  1

  AnAge

• Average gestation period

  7 months

• Average gestation period

  189 days

  AnAge

• Average weaning age

  1 months

• Average time to independence

  5 months

• Average age at sexual or reproductive maturity (female)
  Sex: female

  285 days

  AnAge

• Average age at sexual or reproductive maturity (male)
  Sex: male

  285 days

  AnAge

Lifes­pan/Longevity

The life span of vam­pire bats may be as long as 12 years.

• Range lifespan
  Status: wild

  12 (high) years

• Average lifespan
  Sex: female
  Status: captivity

  19.5 years

  Max Planck Institute for Demographic Research

Be­hav­ior

Much of the be­hav­ior ex­hib­ited by com­mon vam­pire bats re­volves around their meth­ods of ob­tain­ing food. Ter­res­trial move­ment is a crit­i­cal part of stalk­ing and at­tack­ing prey. Un­like other bat species, 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 (see Al­tenbach, 1979 for de­tailed de­scrip­tions and pic­tures of lo­co­mo­tion).

This species is agile and stealthy. Usu­ally when a bat ap­proaches its prey, it does not land di­rectly on the an­i­mal, but rather, lands nearby and walks or hops up to the un­sus­pect­ing vic­tim. It then climbs up the an­i­mal and finds a suit­able meal site. Desmodus ro­tun­dus usu­ally climbs back­wards, or slightly side­ways and is al­ways highly alert while climb­ing. It is light on its feet and moves del­i­cately to avoid de­tec­tion. Once the site has been cho­sen the bat makes a 3mm in­ci­sion in the skin and laps up the blood from the wound. The bite is rel­a­tively pain­less and rarely wakes a sleep­ing vic­tim.

Quick re­flexes and agile move­ment are im­por­tant qual­i­ties when avoid­ing the un­pre­dictible re­sponses of large prey such as live­stock. Jump­ing is one of the vam­pire bat's main avoid­ance tech­niques. It has the abil­ity to jump for­ward, back­ward, and lat­er­ally. These move­ments pro­vide quick es­cape routes from kick­ing hooves, swish­ing tails, and even other preda­tors such as owls and snakes.

Jump­ing is also used to ini­ti­ate flight. Par­tic­u­larly after a large meal, a bat may not be able to take flight di­rectly from the ground. Jump­ing al­lows Desmodus ro­tun­dus to get a heavy stom­ach off the ground at the end of a meal. It is the only species that can launch it­self al­most ver­ti­cally into flight from a hor­i­zon­tal sur­face.

Desmodus ro­tun­dus is a so­cial an­i­mal that hunts and lives in groups. The bats live in colonies con­sist­ing of both males and fe­males. In cap­tiv­ity, dom­i­nance hi­er­ar­chies based on ac­cess to food were ob­served, but there is lit­tle con­clu­sive ev­i­dence of com­plex hi­er­ar­chies in the wild.

Cu­ri­ously, most close as­so­ci­a­tions are formed be­tween sev­eral fe­males or fe­males and their off­spring; adult males do not form close so­cial ties in the roost. Fe­males fre­quent more roost site than males, mak­ing as­so­ci­a­tions in many dif­fer­ent places. The as­so­ci­a­tions be­tween fe­males are main­tained over many years.

Wilkin­son (1985, 1986) re­ported that al­though self-groom­ing oc­curs more often, so­cial groom­ing is an im­por­tant part of the vam­pire bat's be­hav­ior. So­cial groom­ing usu­ally oc­curs be­tween fe­males and their off­spring, but it is also sig­nif­i­cant be­tween adult fe­males. The adult fe­males par­tic­i­pat­ing in groom­ing are usu­ally closely re­lated or roost­mates. Wilkin­son (1986) found that so­cial groom­ing has more to do with food shar­ing than with the re­moval of ec­topar­a­sites. In many in­stances, so­cial groom­ing be­gins with one fe­male ap­proach­ing an­other and groom­ing her for as long as two min­utes. The fe­male being groomed then re­gur­gi­tates part of her blood meal for the groom­ing fe­male. It is also com­mon to see fe­males re­gur­gi­tate food for their off­spring.

Young vam­pire bats do not ex­hibit ag­gres­sive be­hav­ior, al­though they play and wres­tle with other ju­ve­niles. In order to avoid ag­gres­sive en­coun­ters with older bats in the roost, ju­ve­niles per­form a ges­ture of ap­pease­ment where one folded wing is lifted and the body is bent to one side. (Al­tenbach, 1979; Brass, 1994; Mac­don­ald, 1984; Turner, 1975; Walker, 1975; Wilkin­son, 1985; Wilkin­son, 1986)

• Key Behaviors
• flies
• nocturnal
• motile
• social

Com­mu­ni­ca­tion and Per­cep­tion

Vo­cal­iza­tions are most com­mon be­tween mother and off­spring. Small con­tact cries have been heard from the off­spring at 6-12kHz. These usu­ally occur dur­ing food shar­ing. Con­tact calls are also given when the off­spring is try­ing to find its mother. Chem­i­cal cues and touch are also likely to play an im­por­tant role in com­mu­ni­ca­tion.

Vam­pire bats use echolo­ca­tion and vi­sion to nav­i­gate and find prey. They may also use ol­fac­tion and au­di­tory cues to iden­tify prey.

• Communication Channels
• tactile
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• echolocation
• chemical

Food Habits

Desmodus ro­tun­dus feeds ex­clu­sively on the blood of other ver­te­brates. The species is an ob­lig­ate par­a­site. In the wild, the bats feed pref­er­en­tially on live­stock be­cause of their abun­dance, but also prey on wild an­i­mals and hu­mans. In cap­tiv­ity, these bats have also been known to feed on snakes, lizards, toads, croc­o­diles, and tur­tles. (Brass, 1994)

• Primary Diet
• carnivore
  • sanguivore

• Animal Foods
• blood

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Re­search on the an­ti­co­ag­u­lant agents in vam­pire bat saliva may im­prove med­ical treat­ment of some human in­juries and dis­eases. Guano can be har­vested and used as a fer­til­izer.

• Positive Impacts
• source of medicine or drug
• research and education
• produces fertilizer

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

A bite from Desmodus ro­tun­dus can cause in­fec­tions and trans­mit dis­eases car­ried by the bat. In­fec­tions can spread rapidly and cause death. The vam­pire bat trans­mits ra­bies to both hu­mans and do­mes­tic live­stock. Losses to the cat­tle in­dus­try in Latin Amer­ica amount to many mil­lions of dol­lars every year. (Brass, 1994; Lord, 1992)

• Negative Impacts
• injures humans
  • bites or stings
  • carries human disease
• causes or carries domestic animal disease

Con­ser­va­tion Sta­tus

Vam­pire bat pop­u­la­tions have in­creased be­cause of the in­tro­ducion of live­stock in South Amer­ica, pro­vid­ing an abun­dant new source of food. (Turner, 1975)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

Re­searchers have iso­lated an an­ti­co­ag­u­lant called dra­c­ulin in the saliva of vam­pire bats. The an­ti­co­ag­u­lant is a gly­co­pro­tein that stops wounds from clot­ting so that the bat can gain a full meal from its prey.

Vam­pire bats have been the source of many myths and su­per­sti­tions through­out the world. The Eu­ro­peans have tra­di­tion­ally as­so­ci­ated bats with the devil. In Eu­ro­pean pic­tures, the devil often has bat wings. The Per­sians and the Chi­nese, on the other hand, have cho­sen to de­pict the bat in a dif­fer­ent light. The bat is a sym­bol of longevity and hap­pi­ness in tra­di­tional sto­ries and leg­ends. (Fer­nan­dez, et al., Oct. 23, 1998; Walker, 1975)

Con­trib­u­tors

Michael Mul­heisen (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Re­becca An­der­son (au­thor), Uni­ver­sity of Michi­gan-Ann Arbor, Phil Myers (ed­i­tor), Mu­seum of Zo­ol­ogy, Uni­ver­sity of Michi­gan-Ann Arbor.

Ref­er­ences

Green­hall, A.M., G. Jo­er­mann, U. Schmidt, and M. R. Sei­del. 1983. "Mam­malian Species, No. 202 pp.1-6, 3 figs, Desmodus ro­tun­dus". April 8. Amer­i­can So­ci­ety of Mam­mal­o­gists

Al­tenbach, J. 1979. Lo­co­mo­tor Mor­phol­ogy of the Vam­pire Bat, Desmodus ro­tun­dus. Penn­syl­va­nia: Spe­cial Pub­li­ca­tions 6, The Amer­i­can So­ci­ety of Mam­mal­o­gists.

Brass, D. 1994. Ra­bies in Bats, Nat­ural His­tory and Pub­lic Health Im­pli­ca­tions. Ridge­field, Con­necti­cut: Livia Press.

Fer­nan­dez, A., A. Tablante, F. Bar­toli, S. Be­guin, R. Ap­tiz-Cas­tro. Oct. 23, 1998. Ex­pres­sion of bi­o­log­i­cal ac­tiv­ity of dra­c­ulin, the an­ti­co­ag­u­lant fac­tor from vam­pire bat saliva is strictly de­pen­dent on the ap­pro­pri­ate gly­co­sy­la­tion of the na­tive mol­e­cule. Bio­chem­ica et Bio­phys­ica Acta, 1425 (2): 291-299.

Lord, R. 1992. Sea­sonal re­pro­duc­tion of vam­pire bats and its re­la­tion to sea­son­al­ity of bovine ra­bies. Jour­nal of Wildlife Dis­eases, 28 (2): 292-294.

Mac­don­ald, D. 1984. En­cy­clo­pe­dia of Mam­mals. New York: Facts on File.

Turner, D. 1975. The Vam­pire Bat, A Field Study in Be­hav­ior and Ecol­ogy. Bal­ti­more and Lon­don: The Johns Hop­kins Uni­ver­sity Press.

Walker, E. 1975. Mam­mals of the World, 3rd Edi­tion. Bal­ti­more and Lon­don: The Johns Hop­kins Uni­ver­sity Press.

Wilkin­son, G. 1986. So­cial groom­ing in the com­mon vam­pire bat, Desmodus ro­tun­dus. An­i­mal Be­hav­iour, 34 (6): 1880-1889.

Wilkin­son, G. 1985. The so­cial or­ga­ni­za­tion of the com­mon vam­pire bat. Be­hav­ioral Ecol­ogy and So­cio­bi­ol­ogy, 17 (2): 111-122.