Chaerephon pumiluslittle free-tailed bat

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Geographic Range

Chaerephon pumilus, commonly known as the little free-tailed bat, is found from Senegal to Somalia and South Africa. They are also found in Yemen and Madagascar. (Aspetberger, et al., 2004; Bouchard, 1998)

Habitat

Chaerephon pumilus can be found in a variety of habitats, from the semi-arid regions of the African north to areas of cleared rainforest farther south. Specimens have been found widely distributed throughout savannah/woodland terrain of Zambia, Guinea, Sudan and Zimbabwe, as well as the forests of the Congo basin. In Cape Province, South Africa they may be found in the mountainous Cape Macchia Zone. Little free-tailed bats naturally roost in the hollows and crevices of trees and in the crowns of some types of palm trees, where large colonies can find safety. (Bouchard, 1998)

Physical Description

Chaerephon pumilus is a small species of bat. Most little free-tailed bats have a body that is covered with blackish brown fur, fading to pale tan or even white hairs on the ventral surface where the body meets the wings. However, much variation is present throughout their geographic range. Little free-tailed bats have rounded ears, which are over-sized for their heads. Average mass is 11.1 g, average length in observed specimens is 252 mm, and average wingspan is 255 mm. Males are slightly larger than females. Chaerephon pumilus is distinguishable from other members of its genus by its small size and the species’ lack of a lobe projecting between the inner bases of the ears. Males have a forehead crest that creates a recognizable silhouette even when in flight. (Aspetberger, et al., 2004; Bouchard, 1998; Kunz, 2006; Aspetberger, et al., 2004; Bouchard, 1998; Kunz, 2006)

  • Sexual Dimorphism
  • male larger
  • Average mass
    11.1 g
    0.39 oz
  • Average length
    252 mm
    9.92 in
  • Average wingspan
    255 mm
    10.04 in

Reproduction

Little free-tailed bats are social and gregarious, living in large multi-male, multi-female colonies. Group ratios range between 3 and 21 females per male in a harem. Heavier males have larger harems than smaller males. Few females make movements between harems. (Bouchard, 1998; Mickleburgh, et al., 2008)

In Ghana, female little free-tailed bats give birth 3 times per year in synchrony with other females. The breeding season in Chaerephon pumilus varies by location. Timing of pregnancies has been shown to have a loose correlation with rainfall patterns. They have single births as a rule, although twinning has been documented in one case. Gestation period varies by location, from 60 days in the south to 72 days in the northern portion of their range. Uteri in little free-tailed bats are bicornuate, but implantation almost always occurs in the right horn. Young are nursed for 2 to 3 weeks after birth, after which they rapidly attain the ability to fly and feed themselves. Females are sexually mature in the breeding season after their birth. Sexual maturity in males occurred about 5 months after birth in Ghana, but research is inconclusive in other geographical areas studied. (Bouchard, 1998; Vaughan, 1966)

  • Breeding interval
    Little free tailed bats breed at varying intervals dependent on geographic location.
  • Breeding season
    The breeding season for little free-tailed bats varies geographically.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    1
  • Range gestation period
    60 to 72 days
  • Range weaning age
    2 to 3 weeks
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Range age at sexual or reproductive maturity (male)
    5 (low) months

Lactation in little free-tailed bats lasts between 2 and 3 weeks, preceded by a 60 to 72 day gestation period. No paternal investment has been observed. Once the young are weaned, they become independent shortly afterwards. (Bouchard, 1998)

  • 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 information on lifespan in little free-tailed bats.

Behavior

Little free-tailed bats are nocturnal, leaving their roosts at dusk to begin hunting. These bats hunt by themselves and return to their roosts after feeding. Little free-tailed bats often roost with another species of molossid, the larger Mops condylurus. Little free-tailed bats are very social and make a lot of noise before leaving the roost to hunt. Migration has not been reported in this species. (Aspetberger, et al., 2004; Bouchard, 1998)

Home Range

Home range sizes are not reported for little free-tailed bats.

Communication and Perception

Little free-tailed bats primarily use echolocation in navigating their environment, as well as in hunting for food. Echolocation patterns vary geographically. Echolocation calls of Chaerephon pumilus in the Amani Nature Reserve of Tanzania were of a lower frequency and had longer gaps between pulses than in individuals of the same species living in South Africa. It is possible that echolocation calls vary with habitat or prey types. Little free-tailed bats, like most bats, have monochromatic vision. Vision in used in a secondary capacity to echolocation. It has recently been noted that many bats have elevated sensitivity to ultraviolet light, which is most abundant at dawn and dusk. Tactile and chemical cues may also be used extensively in social communication. (Aspetberger, et al., 2004; Bouchard, 1998)

Food Habits

Juvenile little free-tailed bats have been know to have milk and remains of large cockroaches in their stomachs. Adults are purely insectivorous. They eat a wide variety of soft-bodied insects. Food sources remain relatively stable throughout the seasons, but the average size of prey is greatly increased during the rainy season. (Aspetberger, et al., 2004; Bouchard, 1998; Kunz, 2006)

  • Animal Foods
  • insects

Predation

Known predators of little free-tailed bats include bat-hawks (Macheiramphis alcinus), hobby falcons (Falco subbuteo), Wahlberg’s eagles (Hieraaetus wahlbergi), and African goshawks (Accipiter tachiro). These prey birds successfully capture between 1 and 5 bats per night. Chaerephon pumilus may have developed its erratic flight pattern as an anti-predator tactic. Their nocturnal activity and cryptic coloration also help to protect them from some predators. (Aspetberger, et al., 2004; Bouchard, 1998)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Little free-tailed bats are preyed on by many larger African birds and are predators of insect populations. Little free-tailed bats coexist peacefully in roosts with the larger mollosid, Mops condylurus. (Bouchard, 1998; Kunz, 2006; Vaughan, 1966)

Mutualist Species

Economic Importance for Humans: Positive

Little free-tailed bats prey on insects, which help humans by limiting insect pests, such as agricultural pests or insect disease vectors. (Aspetberger, et al., 2004)

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

All bats can be carriers of diseases, such as rabies. Large colonies that roost in buildings are considered a problem as their droppings can create quite a smell. (Aspetberger, et al., 2004)

Conservation Status

Little free-tailed bat populations are large, widespread, and do not seem to be rapidly declining. They are considered "least concern" by the IUCN.

Contributors

Kelcey Mead (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

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal

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.

forest

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

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

polygynous

having more than one female as a mate at one time

riparian

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

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

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.

year-round breeding

breeding takes place throughout the year

References

Aspetberger, F., D. Brandsen, D. Jacobs. 2004. Geographic variation in the morphology, echolocation and diet of the little free-tailed bat, Chaerephon pumilus (Molossidae). African Zoology, 38(2): 245-254.

Bouchard, S. 1998. Chaerephon Pumilus. Toronto, Ontario, Canada: American Society of Mammalogists.

Koopman, K., R. Mumford, J. Heisterberg. 1978. Bat Records from Upper Volta, West Africa. New York, New York, USA: American Museum of Natural History.

Kunz, T. 2006. Bat Ecology. Chicago, IL, USA: University of Chicago Press.

Mickleburgh, S., A. Hutson, P. Racey, J. Ravino. 2008. "Tadarida pumila" (On-line). IUCN Red List. Accessed January 26, 2009 at http://www.iucnredlist.org/details/4317.

Vaughan, T. 1966. Morphology And Flight Characteristics of Molossid Bats. Journal of Mammalogy, 47: 249-260.