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.
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
Vampire bat populations have increased because of the introducion of livestock in South America, providing an abundant new source of food.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
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.
Negative Impacts: injures humans (bites or stings, carries human disease); causes or carries domestic animal disease
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
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.
Animal Foods: blood
Primary Diet: carnivore (Sanguivore )
The common vampire bat is found from Mexico to Argentina and Chile.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
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.
Range elevation: 2400 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest ; scrub forest
Other Habitat Features: caves
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.
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.
Range mass: 15 to 50 g.
Range length: 70 to 90 mm.
Range wingspan: 350 to 400 mm.
Sexual Dimorphism: sexes alike
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 0.194 W.
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.
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.
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 gestation period: 7 months.
Average weaning age: 1 months.
Average time to independence: 5 months.
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 8 g.
Average gestation period: 189 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 285 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 285 days.
