Rhinolophus dentiDent's horseshoe bat

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Geographic Range

Rhinolophus denti is found in arid savanna regions of western and southern Africa. In West Africa they range from southeastern Senegal to northeastern Ghana. In southern Africa they are found primarily in Namibia, Botswana, and northwestern South Africa. A subspecies, R. d. knorri, is found only in Guinea and has an average forearm length of only 37.5 to 40.5 mm. Populations seem to be patchily distributed and western and southern populations seem to be disjunct, although this may reflect insufficient sampling. (Jacobs, et al., 2008; Churchill, et al., 1997; Jacobs, et al., 2008; Churchill, et al., 1997)

Habitat

Dent's horseshoe bats prefer arid savanna climates and roost in caves and cave-like structures, such as abandoned mine shafts and hollow trees. In winter, when the temperature drops below 11 degrees Celsius, they conserve energy by entering hibernation deep inside of caves. (Jacobs, et al., 2008; Mills, 1997)

  • Other Habitat Features
  • caves

Physical Description

Rhinolophus denti is one of the smallest species in the Rhinolophidae family, with an average weight of 6 grams. Their average total length is 70 millimeters with a forearm length between 41 and 43 millimeters. Their fur is long and soft. The color of their fur tends to be light brown or grey on the upper part of their body, with an off white or cream color at the base. The wings are brown with white edges. (Mills, 1997; Watson, 1998; Mills, 1997; Watson, 1998; Mills, 1997; Watson, 1998; Mills, 1997; Watson, 1998)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    6 g
    0.21 oz
  • Range length
    4.3 to 5.7 mm
    0.17 to 0.22 in
  • Average wingspan
    70 mm
    2.76 in

Reproduction

Nothing is truly known about reproduction in Dent's horseshoe bats. However, they may be similar to other species of Rhinolophus, in which males mate with as many females as possible during hibernation. (Mills, 1997)

There is little reported information on reproduction, however, Dent's horseshoe bats may be similar to closely related Rhinolophus species. In Rhinolophus females generally have a single offspring yearly and temperate species tend to reproduce seasonally. Many temperate species experience delayed implantation. They breed once a year and young are thought to be independent at about 2 months old. (Wilson and Reeder, 2005)

  • Breeding interval
    Rhinolophus denti breeds once yearly.
  • Average number of offspring
    1
  • Average time to independence
    2 months

Little is known about parental investment in this species. However, like other Rhinolophus species, mothers give birth to live young and nurse and carry them until they are able to fly, usually after approximately two months. (Mills, 1997)

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

Lifespan/Longevity

There is no available information on longevity in Dent's horseshoe bats. Other small Rhinolophus species can live up to 20 years old. (Wilson and Reeder, 2005)

Behavior

Dent's horseshoe bats roost in colonies. Colonies may have only a few individuals or several hundred. Individuals cluster closely together, both by hanging suspended from the ceiling or clinging to the walls. They seem to prefer humid and cool caves. Dent's horseshoe bats have the ability to enter torpor; an energy saving state by cooling their body temperatures. Torpor allows them to conserve energy while inactive in their roost. Dent's horseshoe bats do not appear to migrate locally or seasonally. (Churchill, et al., 1997; Mills, 1997)

Home Range

There is no information on home ranges in Dent's horseshoe bats. (Mills, 1997)

Communication and Perception

Dent's horseshoe bats have a superb sense of hearing and good eyesight similar to other species in the family. The large fleshy pad around the nose of the animal helps to amplify the ultrasonic calls it emits for echolocation. Echolocation allows them to navigate in total darkness, as well as find and capture insect prey at night. Like other mammals, it is also possible that chemical cues and tactile cues play a role in social communication. (Mills, 1997; Wilson and Reeder, 2005)

Food Habits

Dent's horseshoe bats are nocturnal insectivores, feeding on a variety of small, soft-bodied insects. Insect populations are relatively scarce in the arid habitats these bats occupy and more research is needed to understand their foraging strategies. (Mills, 1997)

  • Animal Foods
  • insects

Predation

There are no specific reports of predation on Dent's horseshoe bats. In general, bats are preyed on by owls and other raptors in flight and by scansorial predators in their roosts. Like other bats, Dent's horseshoe bats use their cryptic coloration, nocturnal activity, and difficult to access roosts to escape much predation. (Wilson and Reeder, 2005)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Dent's horseshoe bats are important predators of insects in their native ecosystems.

Economic Importance for Humans: Positive

Dent's horseshoe bats are important members of native ecosystems. Their predation on flying insects can impact agricultural pest populations, providing a benefit to farmers.

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of Dent's horseshoe bats on humans.

Conservation Status

Rhinolophus denti is considered least concern on the IUCN red list. Roosts may be persecuted sometimes, but populations are considered large and widespread, although patchily distributed, currently. (Watson, 1998)

Other Comments

Rhinolophus swinnyi may be best recognized as a part of Rhinolophus denti. (Jacobs, et al., 2008)

Contributors

Jared Strzelec (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon, Tanya Dewey (editor), Animal Diversity Web.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

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.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

insectivore

An animal that eats mainly insects or spiders.

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

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

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

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.

ultrasound

uses sound above the range of human hearing for either navigation or communication or both

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

Churchill, S., R. Draper, E. Marais. 1997. Cave utilisation by Namibian bats: population, microclimate and roost selection. SOUTH AFRICAN JOURNAL OF WILDLIFE RESEARCH, 27 (2): 44-50.

Jacobs, D., F. Cotterill, P. Taylor, M. Griffin. 2008. "Rhinolophus denti" (On-line). IUCN Red List of Threatened Species. Accessed January 25, 2009 at http://www.iucnredlist.org/details/19538.

Mills, L. 1997. The Complete Book of Southern African Mammals. Struik South Africa: Struik. Accessed January 25, 2009 at http://books.google.com/books?id=CavgCweI1nMC.

Watson, J. 1998. New distributional records for three microchiropteran bats (Vespertillionidae, Rhinolophidae) from the Free State Province, South Africa. SOUTH AFRICAN JOURNAL OF WILDLIFE RESEARCH, 21 (4): 127-131.

Wilson, D., D. Reeder. 2005. Mammal Species of the World: A Taxonomic and Geographic Reference. Baltimore: JHU Press. Accessed January 25, 2009 at http://books.google.com/books?id=JgAMbNSt8ikC.