Anoura geoffroyiGeoffroy's tailless bat

Geographic Range

Anoura geoffroyi, Geoffroy's tailless bat, is found from central Mexico to central South America and in Trinidad and Grenada. (Nowak, 1999; Wilson and Reeder, 1993)

Habitat

Habitat requirements of A. geoffroyi have not been described. Caves where A. geoffroyi have been reported occur in tropical rain forests and in savanna-like cerrado near trees. (Baumgarten and Vieira, 1994; Heideman, et al., 1992; Zortea, 2003)

  • Other Habitat Features
  • caves

Physical Description

Geoffroy's tailless bats have a dull-brown color when viewed from above and a gray-brown color when viewed from below. They usually have a silvery-gray color on the shoulders and neck. No tail is present. Nowak (1999) describes the calcar as rudimentary and the cheek teeth as narrow and elongate. The tongue is long and has papillae, and the muzzle is elongate. The average mass for A. geoffroyi is 15.2 g. In Peru body length ranges from 61 to 71 mm, skull length ranges from 24.3 to 26.6 mm, and forearm length ranges from 41 to 45 mm. (Nowak, 1999)

In central Brazil, males and females were reported to be about the same size. Mean male mass, forearm length and wing area were 14.9 g, 42.1 mm and 91.43 cm2 respectively; mean female mass, forearm length and wing area were 14.7 g, 42.3 mm and 91.77 cm2 respectively. However, in central Trinidad, Heideman observed that “females had slightly longer forearms than males (females 42.3 ± 0.1 mm, males 39.9 ± 0.3 mm).” This difference in forearm length may be related to reproduction, since females carry a single pup until it is ready to fly on its own. (Baumgarten and Vieira, 1994; Heideman, et al., 1992)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    15.2 g
    0.54 oz
  • Average mass
    15.2 g
    0.54 oz
    AnAge
  • Range length
    61 to 71 mm
    2.40 to 2.80 in

Reproduction

No information is available about mating systems of A. geoffroyi. In fact, data are lacking on the mating system of most bats in the family Phyllosomidae. This may be because they are small, nocturnal, and fly--making it difficult to observe mating and courtship.

More research is needed to understand reproductive strategies of A. geoffroyi across its range. Heideman et al. (1992) suggested that Geoffroy's tailless bats have a seasonal cycle “with geographic variation in timing.” In Trinidad mating occurs from July to August. Females give birth to one pup in late November or early December, after a gestation of four months. Births occur between the wet and dry seasons, and lactation occurs in the early dry season. Flowering peaks occur in the dry season, resulting in nectar and pollen abundance. Synchronization of lactation with food abundance may help female bats during a time of high energy demand. Heideman et al. (1992) suggested that reproductive timing of A. geoffroyi in Trinidad may have evolved to accommodate the simultaneous occurrence of lactation and food abundance. (Heideman, et al., 1992; Zortea, 2003)

Two studies carried out in different parts of central Brazil found that A. geoffroyi had a seasonal monoestrous cycle. However, birthing and pregnancy timing differed between the two study sites. Both study sites had wet and dry seasons, but the sites experienced the seasons in different months. Nowak (1999) stated that pregnant A. geoffroyi have been collected in Nicaragua during July, in Costa Rica during March, and inPeru during June, and that lactating females have been collected July, November and December in Mexico. Unless lactation lasts for more than 6 months, this may indicate that in some places the bats undergo two reproductive cylces per year, having young both in summer and late autumn months. (Baumgarten and Vieira, 1994; Nowak, 1999; Zortea, 2003)

  • Breeding interval
    Anoura geoffroyi likely breeds once a year, although females in some populations may have two young per year.
  • Breeding season
    Breeding season varies greatly with geography.
  • Average number of offspring
    1
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    4 months

More research is needed to understand parental care of A. geoffroyi across its range. Females carry pups in flight until the pups can fly on their own. They presumably provide the young with food and protection as well as transportation during this period. The first growth phase of young bats in Brazil involves rapid forearm growth. A young bat’s forearm in Brazil must grow to about 95% of its mother’s forearm length before it flies independently. The second growth phase involves more rapid weight gain. In Brazil, the wing areas of adult females were not greater than the wing areas of males. An increase in forearm length that is faster than weight gain likely enables young bats to fly alone sooner. In Trinidad, Heideman et al. (1992) reported that females had somewhat longer forearms than males (females 42.3 ± 0.1 mm, males 39.9 ± 0.3 mm). (Baumgarten and Vieira, 1994; Heideman, et al., 1992)

More research is needed to understand the father’s role (if any) in postpartum care of offspring. Adult males may sometimes use different roosts than females and young. Baumgarten et al. (1994) found that the number of adult male bats decreased in the cave when pregnant females or females with young were present. (Baumgarten and Vieira, 1994)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

It is likley that like all microchiropterans, these bats live longer than other mammals of similar size. Although there are no data on maximum lifespan, or population age composition, one member of this species in captivity is known to have lived longer than 10 years. (Nowak, 1999)

  • Range lifespan
    Status: captivity
    >10 (high) years
  • Typical lifespan
    Status: captivity
    10 (high) years

Behavior

Anoura geoffroyi is a dexterous flier and is able to hover. Members of this species may roost alone or in groups. Roosting groups may include both sexes or may seasonally include colonies of different sexes. Heideman et al. (1992) reported A. geoffroyi in a cave in Trinidad that left the cave “within 40 minutes of sunset” and “returned from midnight to about dawn.” (Heideman, et al., 1992; Nowak, 1999; Tamsitt and Nagorsen, 1982)

Anoura geoffroyi have been found roosting with other bat species including Anoura cultrata and Anoura caudifer. A tracking study in central Brazil suggests that individual bats roost in the same cave for more than a year. (Tamsitt and Nagorsen, 1982)

Home Range

The size of the home range of these bats has not been reported.

Communication and Perception

Phyllostomids use calls for echolocation and communication. Heideman et al. (1992) described the eyes of A. geoffroyi as large and suggested that the bat relies on vision in addition to echolocation. In addition to use of echolocation, these bats likely have some vocal communication, as is common in the family. Scent probably plays some role in communication, as it does in most mammals, during reproduction. Tactile communication undoubtedly occurs between mothers and their offspring as well as between mates. This for of communication may occur between bats in the roost. (Gould, 1977; Heideman, et al., 1992)

Food Habits

Anoura geoffroyi eats insects, fruit, nectar and pollen. Although this bat is a generalist, it prefers fruit and arthropods in central Brazil. Anoura geoffroyi can be considered a foliage gleaner because it eats insects that are on leaves, nectar and flowers. (Nowak, 1999; Tamsitt and Nagorsen, 1982; Zortea, 2003)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • fruit
  • nectar
  • pollen

Predation

More research is needed to understand predation on A. geoffroyi. It is likely that small mammals, snakes, and birds of prey could take these bats as prey items. Because they are gleaners, taking isects from surfaces, and feeders on fruit and nectar, they are relatively slow in flight, making them more susceptible to aerial predators.

Ecosystem Roles

Anoura geoffroyi eats insects and pollinates plants. In Brazil it is sympatric with two other nectarivorous bats, Glossophaga soricina and Anoura caudifer, with which it may compete. (Baumgarten and Vieira, 1994; Zortea, 2003)

Members of the genus Anoura host macronyssid mites that cause periodontal disease. This may result in the first premolars being lost. (Tamsitt and Nagorsen, 1982)

  • Ecosystem Impact
  • pollinates
Commensal/Parasitic Species
  • macronyssid mites

Economic Importance for Humans: Positive

Anoura geoffroyi eats insects and pollinates plants. However, whether it polinates crops or controls pest populations is not known. (Baumgarten and Vieira, 1994)

Economic Importance for Humans: Negative

No known negative effects on humans.

Conservation Status

Anoura geoffroyi does not appear on the IUCN Red List. No data were returned on searches for Anoura geoffroyi or Anoura at the CITES website. No data were returned on searches for Anoura geoffroyi at the US Federal List website.

Other Comments

Another common name for A. geoffroyi is Geoffroy’s hairy-legged long-tongued bat. (Heideman, et al., 1992)

Contributors

Kim Fackler (author), University of Alaska Fairbanks, Link Olson (editor, instructor), University of Alaska Fairbanks, Nancy Shefferly (editor), Animal Diversity Web.

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

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

crepuscular

active at dawn and dusk

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.

fertilization

union of egg and spermatozoan

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).

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.

nocturnal

active during the night

omnivore

an animal that mainly eats all kinds of things, including plants and animals

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.

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

tactile

uses touch to communicate

tropical

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

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.

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

Baker, R., K. Jones, Jr., D. Carter. 1976. Biology of Bats of the New World Family Phyllostomatidae. Part I. Lubbock, Texas: Texas Tech Press.

Baker, R., K. Jones, Jr., D. Carter. 1977. Biology of Bats of the New World Family Phyllostomatidae. Part II. Lubbock, Texas: Texas Tech Press.

Baker, R., K. Jones, Jr., D. Carter. 1979. Biology of Bats of the New World Family Phyllostomatidae. Part III. Lubbock, Texas: Texas Tech Press.

Baumgarten, J., E. Vieira. 1994. Reproductive seasonality and development of Anoura geoffroyi (Chiroptera: Phyllostomidae) in central Brazil. Mammalia, 58/3: 415-422.

Gould, E. 1977. Echolocation and Communication. Pp. 247-279 in R Baker, K Jones, Jr., D Carter, eds. Biology of Bats of the New World Family Phyllostomatidae. Part II. Lubbock, Texas: Texas Tech Press.

Heideman, P., P. Deoraj, F. Bronson. 1992. Seasonal Reproduction of a tropical bat, Anoura-geoffroyi, in relation to photoperiod. Journal of Reproduction and Fertility, 96/2: 765-773.

Nowak, R. 1999. Walker’s Mammals of the World: Sixth Edition; Volume 1. Baltimore: The John Hopkins University Press.

Tamsitt, J., D. Nagorsen. 1982. Anoura cultrata. Mammalian Species, 179: 1-5.

Wilson, D., D. Reeder. 1993. Mammal Species of the World: A Taxonomic and Geographic Reference; Second Edition. Washington: Smithsonian Institution Press.

Zortea, M. 2003. Reproductive patterns and feeding habits of three nectarivororus bats (Phyllostomidae: Glossophaginae) from the Brazilian Cerrado. Brazilian Journal of Biology, 63/1: 1-9.