Galago zanzibaricus

Geographic Range

Galagoides zanzibaricus , commonly known as Zanzibar bushbabies, can be found in the East African coastal forests from southern Somalia to Mozambique. As the name suggests, they are also native to the island of Zanzibar. However, this species cannot be found on Pemba and Mafia, two nearby islands. Some researchers maintain that the north boundary of this species is the Tana River in Kenya. They are also found up to a few hundred kilometers inland in the Udzungwa Mountains.

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

Galagoides zanzibaricus lives in tropical, lowland coastal forests. They are also found at higher elevations further inland. They have been found at elevations greater than 1,000 m in the montane forests of Tanzania and Malawi. Population densities are highest near rivers. There is little inter-group exchange among G. zanzibaricus as populations are extremely fragmented.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

• Other Habitat Features
• riparian riparian

Physical Description

Zanzibar bushbabies are generally brown in color. The underside is a lighter shade of brown. The fur is heavy and soft. They have stunningly large red eyes which help them to see at night. The ears are extremely large and the hind limbs are strong and significantly longer than the fore limbs. There is little dimorphism between males and females. The average weight of an adult is 146.8 g. The average weight of an infant at birth is 14.1 g. The body length from head to tail ranges from 14 to 15 cm and the tail length varies from 12 to 15 cm.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

This species is polygynous. Females form small, territorial groups. Upon entrance into such a group, a male usually mates with all members (usually 1-3 females). The females provide the vast majority of parental care. Young females stay within their natal groups and young males disperse. Details of their social behavior are not know because of their elusive behavior.

• Mating System
• polygynous polygynous

Reproduction is seasonal, and Zanzibar bushbabies give birth twice a year. Births occur in August to October and February to March. The average gestation period is 120 days. Females usually give birth to one offspring, although in captivity on a few occasions twins have been born. The average number of offspring in captivity is 1.3 but is probably much closer to 1.0 in the wild. Weaning of infants takes place at around four weeks of age. Weaning is done just before the food supply is the lowest (December to January) and directly after food sources are most abundant (May to June). Female G. zanzibaricus mature sexually at around 265 days of age. Males take about 100 days longer to mature (approx. 1 year). The vagina is sealed at all times except during estrus and birth.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous

Little is know about parental investment in Zanzibar bushbabies. Females primarily care for the young. Occasionally, male bushbabies will sleep with a female and what is thought to be their offspring. Female young remain in their natal group.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• post-independence association with parents

Lifespan/Longevity

Some reports estimate maximum longevity in the wild is 16.5 years. The longest lifespan of a captive G. zanzibaricus is 12.2 years.

Behavior

Zanzibar bushbabies are nocturnal, resting during the day and foraging at night. They are arboreal and spectacular climbers. These animals are agile and use their tail for balance. They have the ability to safely run and leap from limb to limb. Both males and females are territorial and maintain non-overlapping territories (occasionally minor overlapping is seen). Male G. zanzibaricus are rarely found in the same territory other males. Occasionally, however, two females occupy the same territory. They usually sleep together but go their different ways during active periods. Galagoides zanzibaricus typically travel between 1,500 and 2,000 meters per night. Young females remain in their natal ranges after males disperse. Male dispersal prevents incest from occuring.

• Key Behaviors
• arboreal arboreal
• scansorial
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• territorial territorial
• social social

Home Range

In one study, the average home range size was found to be about 2.2 ha. Range size varies from 1.6 to 2.8 ha.

Communication and Perception

The large eyes of Zanzibar bushbabies provide excellent vision at night and the large ears provide an acute sense of hearing. Both attributes are important for navigation in the dark. These animals have loud, distinctive calls about which little is known. They may be a sort of "advertising" call, but they also seem to be used as a warning to others when potential predators are nearby. Like most mammals, chemical cues are probably also important in communication.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

The diet of Galagoides zanzibaricus is mostly composed of fruits, insects, and tree gums. Seasonal variation in resource availability plays an important roll in determining what the animals eat. For example, when it rains a lot there may be an abundance of insects, but when no rain falls Zanzibar bushbabies must look to other resources. Occasionally a Zanzibar Bushbaby will prey on other small animals.

• Primary Diet
• omnivore omnivore

• Animal Foods
• mammals
• insects

• Plant Foods
• leaves
• fruit
• nectar
• sap or other plant fluids

Predation

Their arboreal lifestyle protects Zanzibar bushbabies from many potential predators. They produce warning calls in the presence of genets and puff adders , suggesting that they may be predators of G. zanzibaricus .

Ecosystem Roles

Zanzibar bushbabies may disperse the seeds of the fruits they consume.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Zanzibar bushbabies are important members of the ecosystems in which they live, they are also a potential draw for ecotourism efforts.

• Positive Impacts
• ecotourism ecotourism

Economic Importance for Humans: Negative

There are no negative impacts of Galagoides zanzibaricus on humans.

Conservation Status

Galagoides zanzibaricus is classified as vulnerable on the IUCN Red List. Although the species as a whole is widespread and fairly common, its fragmented range results in potential extinction of individual populations. The main threat to this creature is habitat loss due to urbanization and deforestization. Also, the indigenous forests used by G. zanzibaricus are being replaced with exotic conifers, which do not provide appropriate habitat for this species. Zanzibar bushbabies are protected by law in Kenya as well as in certain conservatories such as the Tanzania Forest Conservation Group. Despite these efforts, only about 12% of their total range is protected.

Other Comments

The phylogenetics of G. zanzibaricus has a complicated history. In recent years this creature's place within primate phylogeny has been anything but stable. Three major techniques have been utilized: morphological analyses, molecular analyses, and analysis of vocalization data. Analyses based on these data support different hypotheses of relationship and outgroup rooting seems to be a problem. This species was previously known as Galago zanzibaricus , it was then placed in the genus Galagoides as Galagoides zanzibaricus , and was recently returned to the genus Galago .

Galagoides zanzibaricus has been divided into two subspecies Galago zanzibaricus zanzibaricus and Galago zanzibaricus cocos . There are few morphological differences between the two, and experts cannot tell them apart visually. However, they have highly distinctive vocalizations and Galagoides zanzibaricus cocos was recently elevated to species status, Galagoides cocos .

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Ryan Satovsky (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.

References

Butynski, T. 2004. "Primates on Mt. Kasigau, Kaya Rabai and along the Tana River, Kenya: Preparing for Red List Assesments and Conservation Action" (On-line pdf). Accessed March 20, 2006 at http://www.cepf.net/ImageCache/cepf/content/pdfs/final_2eci_2eprimateskasigau_2epdf/v1/final.ci.primateskasigau.pdf .

Harcourt, C., L. Nash. 1986. Social Organization of Galagos in Kenyan Coastal Forests: I. Galago zanzibaricus. American Journal of Primatology , 10/4: 339-355.

Masters, J., D. Brothers. 2002. Lack of Congruence Between Morphological and Molecular Data in Reconstructing the Phylogeny of the Galagonidae. American Journal of Physical Anthropology , 117/1: 79-93.

Nash, L. 1983. Reproductive Patterns in Galagos (Galago zanzibaricus and Galago garnettii) in Relation to Climatic Variability. American Journal of Primatology , 5/3: 181-196.

Nunn, C., R. Barton. 1999. "Allometric slopes and independent contrasts: a comparative test of Kleiber’s law in primate ranging patterns" (On-line). Accessed March 19, 2006 at http://www.eva.mpg.de/primat/staff/charles_nunn/Nunn_Barton.htm .

Nunn, C. 1999. "Collective action, free-riders, and male extragroup conflict" (On-line). Accessed March 19, 2006 at http://www.eva.mpg.de/primat/staff/charles_nunn/Nunn2000-loudcalls.htm .

Primate Specialist Group, 2004. "IUCN Red List of Threatened Species" (On-line). Accessed March 20, 2006 at http://www.redlist.org/search/details.php?species=8790 .

Schulke, O. 2002. "Living apart together- Patterns, ecological basis, and reproductiv consequences of life in dispersed pairs of fork-marked lemurs" (On-line pdf). Accessed March 20, 2006 at http://opus.bibliothek.uni-wuerzburg.de/opus/volltexte/2003/502/pdf/Schuelke.pdf#search='galago%20zanzibaricus%20harcourt' .

2005. "An Age entry for Galagoides zanzibaricus" (On-line). Accessed March 20, 2006 at http://genomics.senescence.info/species/entry.php?species=Galagoides_zanzibaricus .

2003. "Ngaramia Riverine Forest Conservation Project" (On-line). Accessed March 19, 2006 at http://www.tfcg.org/docs/project_ngaramia.htm .