Diphylla ecaudatahairy-legged vampire bat

Geographic Range

Diphylla ecaudata can be found from southern Texas to eastern Peru and southern Brazil (Carattini 2001; Texas Parks & Wildlife 1994).

Habitat

Diphylla ecaudata is primarily an inhabitant of tropical and subtropical forestlands. They can be found in both mesic, forested and arid, open areas. During the daytime these bats roost in caves, mine tunnels, hollow trees, or abandoned buildings ("Vampire Bats" 2001; Texas Parks & Wildlife 1994).

Physical Description

Diphylla ecaudata, commonly referred to as hairy-legged vampire bats, range from reddish brown to sooty brown in color. They have a narrow, hairy interfemoral membrane and a pug-nosed snout. Hairy-legged vampire bats are distinguished by their typically smaller body and ears than other vampire bats. They also have a total of 26 teeth, more than other vampire bat species. Hairy-legged vampire bats have highly modified upper incisors. These incisors are larger than the canines and occlude against each other so that they are continuously sharpened to a very fine edge. The outer incisors are much reduced (Carattini 2001; Texas Parks and Wildlife 1994).

  • Range mass
    30 to 40 g
    1.06 to 1.41 oz

Reproduction

Diphylla ecaudata is sexually mature at 9 months and reproductively active throughout the year. Common months of pregnancy for females have been reported to be in March, July, August, October, and November. Gestation is 6 to 8 months. The number of embryos per female is normally one and they may produce a single offspring one or two times a year (Texas Parks & Wildlife 1994).

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

Behavior

Hairy-legged vampire bats are nocturnal. They roost either alone or in small groups of 12 or less. In one study, D. ecaudata was observed to be more solitary and did not gather into groups when in the presence of other bats in a cave. They have a structured society in which they build strong social bonds with other bats in the colony. They are intelligent mammals. Diphylla ecaudata groom each other and help other bats in need. By learning to recognize other bats in a colony through voice and smell, bats can communicate with each other when necessary. A bat can beg for food and another bat who has built a strong bond with that bat will regurgitate blood for it to eat, demonstrating reciprocal social behavior. These bats are shy, quick to take flight, and seem to rapidly vacate roosts once they have been disturbed by humans ("Vampire Bats" 2001; Texas Parks & Wildlife 1994).

Communication and Perception

Food Habits

Hairy-legged vampire bats feed on the blood of warm-blooded vertebrates, mostly birds, including domestic chickens. Through the use of heat sensors on their nose, these vampire bats can seek an area of the prey's skin where there is a good amount of blood close to the surface. They lick the skin to soften the bite area and to rid it of hair or feathers. They then bite a small, V-shaped wound which is about 2.5 mm deep. Usually the victim is not aware of the bite. It has been observed that these bats attack the legs and cloacal region of chickens and then suck up the blood while in an upright position. When feeding on birds roosting in trees, these bats grip a branch with their hind feet and thumbs. They then situate themselves underneath a bird and make an incision. Terrestrial locomotion has not been reported in this species of vampire bat. An anticoagulant in the saliva allows blood to flow freely from the wound.

The feeding process usually takes about a half an hour. An adult may consume about 5 teaspoons of blood, which is about half of its body weight. After the bat feeds, it urinates continuously until it is light enough to fly again. The longest this bat can go without eating is 2 nights. If Diphylla ecaudata does not eat for more than 2 nights in a row then it will die from starvation. It has been estimated that about 1/3 of hairy-legged vampire bats does not eat each night, they must then rely on shared food from roost mates (Schutt & Altenbach 1997; Tomlinson; Texas Parks & Wildlife 1994).

Economic Importance for Humans: Positive

Diphylla ecaudata produces an anticoagulant in their saliva that is about 20 times more powerful than any other anticoagulant known. The saliva has been used as a blood-thinning drug to treat heart attacks and strokes in humans ("Vampire Bats" 2001).

Economic Importance for Humans: Negative

Because hairy-legged vampire bats almost always feed by taking the blood of birds, they rarely attack humans. If they were to bite a human, the wounds would not be serious. However, it is possible for them to transmit rabies and other diseases through those wounds. Because hairy-legged vampire bats may occasionally take blood from livestock and trasmit diseases, they are potentially economically important to cattlemen and sportsmen of Texas as a reservoir of bovine paralytic rabies (Texas Parks & Wildlife 1994; Carattini 2001; Britannica 1999-2000).

Conservation Status

Hairy-legged vampire bats are the rarest of the three vampire bat species (McCarthy 1987).

Other Comments

While in the wild, this species of vampire bat may live about 9 years. In captivity they may survive much longer ("Vampire Bats" 2001).

Contributors

Krystal Owens (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

References

2001. "Vampire Bats" (On-line). Accessed March 21, 2001 at http://www.angelfire.com/va/vampirebats/.

Carattini, L. 2001. "The Vampire Bat" (On-line). Accessed March 21, 2001 at http://va.essortment.com/batvampiredesm_rggj.htm.

Encyclopaedia Britannica, 1999-2000. "Vampire bat" (On-line). Accessed March 21, 2001 at wysiwyg://42/http://www.britannica.com/b...1+1+74754,00.html?query=diaemus%20youn.

McCarthy, T. 1987. Distributional records of bats from the Caribbean lowlands of Belize and adjacent Guatemala and Mexico. Studies in Neotropical Mammalogy, 39: 137-162.

Schutt, Jr., W., J. Altenbach. 1997. A Sixth Digit in Diphylla ecaudata, the Hairy Legged Vampire Bat. Mammalia, 61 (2): 280-285.

Texas Parks& Wildlife, 1994. "Hairy Legged Vampire" (On-line). Accessed March 21, 2001 at http://www.nsrl.ttu.edu/tmot1/diphecau.htm.

Tomlinson, D. "Natural History of the Vampire" (On-line). Accessed March 20, 2001 at http://www.batconservation.org/content/meetourbats/vampire.htm.