Vampyrum spectrumspectral bat

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Geographic Range

Vampyrum spectrum lives primarily in northern South America and Central America. Their range extends from central Brazil and Peru to southern Mexico. They are also found on Trinidad in the Antilles. (Vehrencamp, et al., 1977; Nowak, 1999; Navarro and Wilson, 1982)

Habitat

They roost in dense, lowland forest below 1,650 m elevation, usually near a river or stream. They are also found in other moist, evergreen forest, yards, secondary growth woodlands, forest edges, and swampy areas. They have been observed roosting in human structures and hollow trees. (Vehrencamp, et al., 1977; Nowak, 1999; Navarro and Wilson, 1982)

  • Range elevation
    1650 (high) m
    5413.39 (high) ft

Physical Description

Vampyrum spectrum is the largest bat species in the New World. Adults weigh between 145 and 190 g, and have a wingspan of 762-914 mm (some exceed 1 m). Head and body length is 125 to 135 mm, there is no tail. The ears are rounded and large, extending to the nose when laid forward, they measure 39 to 42 mm in length. The noseleaf is also large, 17 mm in length on average. The majority of the body is reddish brown, with a slightly paler underside. The fur is short and and fine. This large bat species is distinguished from other large phyllostomids by their generally larger size, lack of a tail, and by the presence of 4 upper and lower incisors as compared to 4 above and 2 below in the similar species Chrotopterus auritus and Phyllostomus hastatus. The dental formula is 2/2, 1/1, 2/3, 3/3 = 34. (Greenhall, 1968; Vehrencamp, et al., 1977; Nowak, 1999; Navarro and Wilson, 1982)

  • Sexual Dimorphism
  • male larger
  • Range mass
    170 to 180 g
    5.99 to 6.34 oz
  • Range wingspan
    700 to 900 mm
    27.56 to 35.43 in

Reproduction

These bats form monogamous pairs, possibly for life. (Greenhall, 1968; Vehrencamp, et al., 1977; Nowak, 1999)

The estrous cycle, gestation period, and details of the early growth of young have not been determined for this species. Births have been recorded from May to July but data are scarce. It's possible that births occur at the end of the dry season and beginning of the rainy season in the regions where these bats live. (Greenhall, 1968; Vehrencamp, et al., 1977; Nowak, 1999; Navarro and Wilson, 1982)

  • Breeding interval
    These bats breed once yearly.
  • Breeding season
    The breeding season is unknown.
  • Average number of offspring
    1

Both adults assist in the rearing of young. Both parents bring food back to roosts for their young and are solicitous of the young until they reach independence. Males are known to wrap their wings around both mothers and their young while roosting. (Greenhall, 1968; Nowak, 1999)

Lifespan/Longevity

In captivity, V. spectrum can live for up to 5.5 years. Their longevity in the wild is unknown. (Greenhall, 1968; Nowak, 1999; Navarro and Wilson, 1982)

  • Range lifespan
    Status: captivity
    5.5 (high) years

Behavior

Vampyrum spectrum emerges from roosts at dusk to forage for prey. These bats form nesting groups of up to five individuals in hollow trees, often near a stream or river (though this is based on limited data). The group consists of a breeding pair and two or three of their non-breeding offspring. One adult, usually the female, always stays in the nest with the young. Both parents bring food back to the roost, presumably to share with their young or mates. One radio-tagged male foraged over an area of 3.2 hectares for 1 to 4.5 hours at a time. Their flight has been characterized as slow, maneuverable, and generally close to the ground. Their wing morphology allows them to fly in cluttered spaces and lift off while carrying large prey items. (Vehrencamp, et al., 1977; Nowak, 1999; Navarro and Wilson, 1982)

Communication and Perception

These bats presumably communicate among themselves using the modes of communication widely used in mammals: chemical, auditory, visual, and tactile modes, though this has not been carefully studied in these animals. Males enclose females and their young in their wings while roosting. (Nowak, 1999; Navarro and Wilson, 1982)

These bats use echolocation to help them navigate during flight and prey location. They have been observed using vision to locate prey, which they then capture with a stealthy approach. It has been suggested that they use their sense of smell to locate roosting birds and other prey at night. (Nowak, 1999; Navarro and Wilson, 1982)

Food Habits

The diet of V. spectrum includes a number of avian, bat, and rodent species. Preferred birds are usually gregarious, or have a very strong odor, and typically roost on branches as opposed to cavities. Prey is apparently located by scent more than by sight or echolocation, and following location it is carefully stalked before a strike is made. These bats begin feeding around dusk, and may have several feeding periods throughout the night. Adults typically feed solitarily, while their mate stays in the nest with the young. Remains of 84 birds of 18 species were found in a single V. spectrum roost. (Vehrencamp, et al., 1977; Nowak, 1999; Navarro and Wilson, 1982)

These bats were previously thought to feed on blood, hence their common name, "False Vampire". It is thought that they may also eat fruit but a mated pair kept in captivity for 5 years refused any fruit offered to them. (Greenhall, 1968; Nowak, 1999; Navarro and Wilson, 1982)

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • birds
  • mammals
  • insects

Predation

Predation on V. spectrum has not been described, although it is likely that young in roosts can be taken by large, arboreal snakes and other arboreal predators, such as coatis and cat species. They may also be taken by large birds of prey, such as owls and eagles, while in flight.

Ecosystem Roles

Vampyrum spectrum are large, predatory bats which impact their prey communities, especially rodents, birds, and other bats.

Economic Importance for Humans: Positive

The economic importance of V. spectrum to humans is not known.

Economic Importance for Humans: Negative

There are no known adverse affects of V. spectrum on humans.

Conservation Status

Vampyrum spectrum has been designated as 'Lower risk / near threatened' by the IUCN. ("International Union for the Conservation of Nature and Natural Resources", 1996)

Contributors

David Hamman (author), Michigan State University, Barbara Lundrigan (editor), Michigan State University.

Glossary

Neotropical

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

World Map

acoustic

uses sound to communicate

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

echolocation

The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.

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.

female parental care

parental care is carried out by females

forest

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

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

male parental care

parental care is carried out by males

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

nocturnal

active during the night

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.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

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

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

IUCN Redlist. 1996. "International Union for the Conservation of Nature and Natural Resources" (On-line ). Accessed May 12, 2003 at http://www.redlist.org/.

Engstrom, M., F. Reid. 2003. What's in a Name?. Bats Magazine, 21/1. Accessed 05/24.03 at http://www.batcon.org/batsmag/feature.html.

Greenhall, A. 1968. Notes on the behavior of the false vampire bat. Journal of Mammalogy, 49: 337-340.

Navarro, D., D. Wilson. 1982. Vampyrum spectrum. Mammalian Species, 184: 1-4. Accessed 05/24/03 at http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/default.html.

Nowak, R. 1999. Walker's Mammals of the World. Baltimore: The Johns Hopkins University Press.

Vehrencamp, S., F. Stiles, J. Bradbury. 1977. Observations on the foraging behavior and avian prey of the neotropical carnivorous bat, Vampyrum spectrum. Journal of Mammalogy, 58: 469-477.