Diaemus youngi
white-winged vampire bat

Diaemus youngi has been recorded in throughout tropical South America, including parts of Paraguayan Chaco, Venezuela, Costa Rica, Mexico, Belize, Bolivia, Argentina, Brazil, and Trinidad. However, little work has been done on this rare species, therefore the range may be larger than what has been documented. (Greenhall, et al., 1983)

Diaemus youngi has been found in moist tropical and dry forests. They have been found roosting in caves, tree hollows, and on the edges of banana tree plantations. (Nowak, 1997; Elizondo, 1999)

Head and body length of white-winged vampire bats is about 85 mm, there is no external tail. The forearm length is approximately 50-56 mm. Adults weigh approximately 30-45 grams. The pelage is usually a shiny clay color, light brown, or dark cinnamon brown. The edges of the wings are white, and the membrane between the second and third fingers is largely white. They have a peculiar short thumb with a single pad under the metacarpal. The slightly re-curved lower incisors with their unique system of cusps distinguish this genus from Desmodus. Diaemus youngi is the only bat known to have 22 permanent teeth. The other two vampire bat species (Desmodus rotundus and Diphylla ecaudata) lack the second upper molar and only have 20. (Nowak, 1997)

The mating system has not been documented in this species. However, related species are polygynous.

Little is known about reproduction in this species. However, the common vampire bat, Desmodus rotundus, breeds throughout the year, bearing a single young after an 8-9 month gestation. (Greenhall, et al., 1983; Lord, 1992)

Little information exists for this speceis. However, in related species young are nursed and cared for by females for several months after birth, at which time the young become independent. Young bats are typically born naked and helpless and develop rapidly in the weeks following their birth.

The lifespan of Diaemus youngi has only been documented in captivity where they can live 20 years. The relate common vampire bat (Desmodus rotundus) lives around 9 years in the wild. (Marlett , 2001)

White-winged vampire bats have not been observed locomoting on the ground in the wild. However, they are morphologically similar to common vampire bats (Desmodus rotundus), suggesting that they may be capable of walking on the ground. To feed, these bats select their prey, then cautiously moves across a branch until they are close enough to extract blood from the prey’s feet. An incision is made after preliminary licks have been made on one of the digits, and blood is extracted by further licking the wound. Anticoagulants from the bat’s saliva ensure that blood flows freely. If the prey is startled or moves, the bat will hide under the branch until it can move back to the feeding site. Feeding time lasts around 15 minutes, then the bat flies away.

White-winged vampire bats are nocturnal and roost in small groups. (Schutt, et al., 1999)

There is no documented research on communication was found for this species. However, all microchiropterans utilize echolocation for navigation and possibly spatial organization. In addition, most bats use audible vocalizations, smells, and touch for communicating among individuals. In addition bats use vision, smell, touch, and auditory signals for perceiving their environment.

White-winged vampire bats feed mostly on blood from various bird species, including free-ranging poultry species (chickens, Guinea fowl, and turkeys). (Nowak, 1997; Schutt, et al., 1999)

Although little is known about predation on this species, it is likely that most predation occurs on young in roosts by small predators, such as snakes, and by birds of prey on bats leaving roosts. (Tuttle, 1996)

There is insufficient information on Diaemus youngi and its potential role in the ecosystem. It is possible that this species harbors and transmits diseases to various birds. They impact bird populations through parasitism, by feeding on their blood. (Nowak, 1997; Schutt, et al., 1999)

There is no information available on economic importance of this species.

Diaemus youngi is considered a pest because individuals sometimes feed on the blood of domestic poultry species. They may also be a carrier of rabies and other infectious diseases. (Elizondo, 1999)

This species is not protected under CITES or IUCN. The status of populations is poorly known. (Greenhall, et al., 1983)