Galago gabonensisGabon bushbaby

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Geographic Range

Gabon bushbabies are found mainly between the Sanaga and Ogooue Rivers in Cameroon, as well as the Rio Muni mainland region of Equatorial Guinea. They have also been recorded south of the Ogooue River in Gabon. (Grubb, et al., 2003)

Habitat

Gabon bushbabies occupy tropical forests with high annual rainfall. Forest level occupation is unknown, although they are likely to be found in mid to low forest canopy levels because of their dietary niche. Gabon receives an average annual rainfall of 170 cm, most of which falls over only a third of the year. Two rainy seasons between September and December and March to June account for this rainfall. Temperatures range from a maximum of around 30 degrees C to a minimum of around 20 degrees C (Charles-Dominique, 1977a). The elevation of the documented occupation areas of Gabon range from 150 to 1000 m (Willamowius, 2008). Due to lower human populations in Gabon, the country is not thought to lose a large proportion of its forests due to deforestation each year (Barnes, 2008). (Barnes, 2008; Charles-Dominique, 1977a; Willamowius, 1999)

  • Range elevation
    150 to 1000 m
    492.13 to 3280.84 ft

Physical Description

Gabon bushbabies are small primates with long, fully furred tails and large ears (Kingdon, 2004). The tail is about 25.4 cm in length and the average body length is 21.6 cm (Grzimek et al., 2005). The closest relative of G. gabonensis is Galago alleni. Galago gabonensis has been described as browner in color than Galago alleni (Groves, 1989). Like other primates, Gabon bushbabies have opposable thumbs that can be used for gripping branches. They are nocturnal and have large eyes with a reflective tapetum lucidum. This improves vision in low-light conditions and is common among nocturnal carnivorous species (Gron 2008). Although ear morphology has not been specifically described in Gabon bushbabies, other bushbabies have ears that can move independently of one another and that are the largest relative to their body size among primates (Ankel-Simons, 2007). These extremely large and mobile ears likely aid G. gabonensis in hunting for insects. (Ankel-Simons, 2007; Gron, 2008; Groves, 1989)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    250 to 450 g
    8.81 to 15.86 oz
  • Average length
    21.6 cm
    8.50 in

Reproduction

Female Gabon bushbabies are likely capable of two birth seasons per year, based on the presence of visible estrus swellings. Females in other species of Galago mate with more than one male during a single estrus cycle (Pullen et al., 2002), it is possible that Gabon bushbabies do as well. Galago moholi copulations in the wild last on average 9 minutes, with 2 to 5 prolonged mounts punctuated with rest and grooming (Pullen et al., 2002). (Pullen, et al., 2000)

Although gestation length could not be found in the primary literature for Gabon bushbabies, gestation length in other Galago species can range from 111 days to 142 days (Charles-Dominique, 1977a), with smaller species exhibiting shorter gestational lengths. Since Gabon bushbabies are comparatively large, they are likely to have gestation lengths that fall along the longer end of the spectrum and birth masses towards the higher end of the range. Among Galago species, young develop fur between 2 and 3 weeks of age (Charles-Dominique, 1977a). Most Galago species give birth several times a year, with births often peaking at times when fruits and insects are abundant. Other aspects of their reproduction may be similar to their close relative, Galago alleni. (Charles-Dominique, 1977a)

  • Breeding interval
    Breeding intervals are not reported for G. gabonensis. Female Galago alleni generally breed once yearly.
  • Breeding season
    Galago species generally breed throughout the year, with births peaking when fruits and insects are abundant.
  • Range number of offspring
    1 to 2
  • Average number of offspring
    2
  • Range weaning age
    10 to 14 weeks
  • Average time to independence
    10 months
  • Average age at sexual or reproductive maturity (female)
    10 months
  • Average age at sexual or reproductive maturity (male)
    10 months

Female bushbabies "park" their infants on tree branches while they forage nearby. This parking sometimes lasts up to three hours, with the mothers intermittently checking on the infant or juvenile. If the offspring is in distress, it may emit a distress call, to which the mother quickly responds (Charles-Dominique, 1977a). Independent locomotion and exploration begins at around 2 to 3 weeks of age and consumption of solid food usually begins at around one month of age, when the infant starts taking food from its mother's mouth (Charles-Dominique, 1977a). Males don't seem to directly care for young, although they may keep other males away through territorial defense. (Charles-Dominique, 1977a)

  • Parental Investment
  • precocial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female
  • extended period of juvenile learning

Lifespan/Longevity

No long-term wild study of longevity in Gabon bushbabies has ever taken place, and specific information on lifespan is lacking. Other bushbabies have been documented living into their mid-teens (Ross, 1988). (Ross, 1988)

Behavior

Bushbabies are commonly described as primarily solitary animals, although this may not necessarily be the case due to the difficulty of observing them in the wild. In a population of closely related Galago alleni, individuals have been observed in association with one to several conspecifics about half the time. Congregation is most commonly observed in the very early morning before dawn (Ambrose, 2003). It is likely that Gabon bushbabies locomote mainly through vertical cling-leaping, which is the process of leaping between vertical supports. Galago alleni engages in vertical cling leap locomotion, which allows for very efficient leaping between tree trunks (Charles-Dominique, 1977a). (Ambrose, 2003; Charles-Dominique, 1977a)

Home Range

Data regarding the home range of Galago gabonensis is lacking. In the closely related Galago alleni, female ranges may overlap with one another and the ranges of males usually overlap with that of at least one female. Galago alleni male home ranges are large and may overlap with the ranges of more than 8 different females. Males are typically territorial of their home range towards other males (Charles-Dominique 1977a). (Charles-Dominique, 1977a)

Communication and Perception

The vocalizations of bushbabies (Galago species) have been divided into three categories: social contact calls, threat and distress calls, and attention and alarm calls (Charles-Dominique, 1977a). Great diversity exists between bushbaby species vocalizations and vocalizations of Gabon bushbabies have been described as croak calls. Croaks are used as calls between conspecifics over great distances and they are typically relatively short sequences (Grubb et al., 2003). (Charles-Dominique, 1977a; Grubb, et al., 2003)

Food Habits

Gabon bushbabies are omnivorous, eating primarily animal prey, fruit, and gums (Charles-Dominique, 1977a). Their animal prey consists mainly of arthropods. (Charles-Dominique, 1977a)

  • Animal Foods
  • insects
  • Plant Foods
  • fruit
  • sap or other plant fluids

Predation

Potential predators of Gabon bushbabies include long-nosed mongooses (Herpestes naso) and crested genets (Genetta cristata) (Mzilikazi et al., 2006). Potential primate predators include grey-cheeked mangabeys (Lophocebus albigena) and common chimpanzees (Pan troglodytes). Chimpanzees has been observed "fishing" for bushbabies by poking a large stick down a tree hole (Byrne, 2007). They are likely to also fall prey to forest raptors and arboreal snakes. Bushbabies are active at night, which lowers their risk of predation, and they are agile and alert. Their arboreal habits lowers their risk of predation as well. Bushbabies are generally cryptically colored. (Byrne, 2007; Milikazi, et al., 2006)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

It is likely that Gabon bushbabies disperse seeds and help to regulate insect populations.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Gabon bushbabies are occasionally found at bushmeat markets, although they are not commonly hunted and consumed by humans. They are also occasionally sold as pets for human entertainment (Bowen-Jones & Pendry, 1999). (Bowen-Jones and Pendry, 1999)

Economic Importance for Humans: Negative

There are no adverse effects of Galago gabonensis on humans.

Conservation Status

Galago gabonensis is recognized as "least concern" by the IUCN under the name Sciurocheirus gabonensis. It is possible that the Gabon Bushbaby faces similar conservation challenges as G. alleni. Deforestation is currently the biggest threat to Gabon's tropical forests (Gron 2008). (Gron, 2008)

Other Comments

Galago gabonensis is recognized under the name Sciurocheirus gabonensis by some authors. (Groves, 1989; Grubb, et al., 2003)

Contributors

Carolynn Fitterer (author), Michigan State University, Pamela Rasmussen (editor, instructor), Michigan State University.

Glossary

Ethiopian

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

World Map

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

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

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.

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.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

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

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

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.

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.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

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.

year-round breeding

breeding takes place throughout the year

young precocial

young are relatively well-developed when born

References

Ambrose, L. 2003. Three acoustic forms of Allen’s galagos (Primates; Galagonidae) in the Central African region. Primates, 44: 25-39.

Ankel-Simons, F. 2007. Primate Anatomy: an introduction. San Diego: Elsevier Acad Pr.

Barnes, R. 2008. Deforestation trends in tropical Africa. African Journal of Ecology, 28(3): 161-173.

Bowen-Jones, E., S. Pendry. 1999. The threat to primates and other mammals from the bushmeat trade in Africa, and how this threat could be diminished.. Oryx, 33(3): 233-46.

Byrne, R. 2007. Animal cognition: bring me my spear. Curr Biol, 17(5): 164-5.

Charles-Dominique, P. 1977a. Ecology and behavior of nocturnal primates: prosimians of equatorial West Africa. New York: Columbia U Pr.

Gron, K. 2008. "Primate Info Net" (On-line). Lesser bushbaby Galago sp. Accessed August 04, 2008 at http://pin.primate.wisc.edu/factsheets/entry/lesser_bushbaby/taxon.

Groves, C. 1989. A theory of primate and human evolution. New York: Oxford University Press.

Grubb, P., T. Butynski, J. Oates, S. Bearder, T. Disotell, C. Groves, T. Struhsaker. 2003. Assessment of the Diversity of African Primates. International Journal of Primatology, 24: 1301-1357.

Grzimek, B., N. Schlager, D. Olendorf, M. McDade. 2005. Grzimek's Animal Life Encyclopedia. Thomson Gale.

Kingdon, J. 2004. The Kingdon pocket guide to African mammals. Princeton, NY: Princeton U Pr.

Milikazi, N., J. Masters, B. Lovegrove. 2006. Lack of torpor in free-ranging southern lesser galagos, Galago moholi: ecological and physiological considerations. Folia Primatologica, 77: 465-476.

Ollivier, F., D. Samuelson, D. Brooks, M. Kallberg, A. Komaromy. 2004. Comparative morphology of the tapetum lucidum (among selected species). Vet Ophthalmol, 1: 11-22.

Pullen, S., S. Bearder, A. Dixson. 2000. Preliminary observations on sexual behavior and the mating system in free-ranging lesser galagos (Galago moholi).. Am J Primatol, 51(1): 79-88.

Ross, C. 1988. The intrinsic rate of natural increase and reproductive effort in primates. J Zool London, 214(2): 199-219.

Willamowius, J. 1999. "Map Generator" (On-line). Gabon Elevation Digital Map. Accessed August 04, 2008 at http://www.mapgenerator.us/shop/Maps-4865.html.