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)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,
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)
- Terrestrial Biomes
- savanna or grassland
- Other Habitat Features
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)is one of the smallest species in the
- 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
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)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- breeds once yearly.
- Average number of offspring
- 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
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)
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)
- Communication Channels
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
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
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.
Rhinolophus swinnyi may be best recognized as a part of (Jacobs, et al., 2008).
Jared Strzelec (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon, Tanya Dewey (editor), Animal Diversity Web.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
uses sound to communicate
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.
an animal that mainly eats meat
uses smells or other chemicals to communicate
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.
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.
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.
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.
An animal that eats mainly insects or spiders.
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).
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.
active during the night
- seasonal breeding
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
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).
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.
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.
uses sound above the range of human hearing for either navigation or communication or both
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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.