Galago 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. (Butynski, 2004)
Galago 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. ("Ngaramia Riverine Forest Conservation Project", 2003; Butynski, 2004)
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. ("An Age entry for Galagoides zanzibaricus", 2005; Butynski, 2004)
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. (Butynski, 2004; Nash, 1983; Nunn, 1999)
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. ("An Age entry for Galagoides zanzibaricus", 2005; Nash, 1983; Schulke, 2002)
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. (Nash, 1983)
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. Galago 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. (Butynski, 2004; Harcourt and Nash, 1986; Nunn, 1999)
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. (Butynski, 2004; Nash, 1983)
The diet of Galago 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. (Butynski, 2004; Nash, 1983)
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. (Butynski, 2004; Nash, 1983)
Zanzibar bushbabies may disperse the seeds of the fruits they consume.
Zanzibar bushbabies are important members of the ecosystems in which they live, they are also a potential draw for ecotourism efforts.
There are no negative impacts of Galago zanzibaricus on humans.
Galago 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. ("Ngaramia Riverine Forest Conservation Project", 2003; Butynski, 2004)
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. (Butynski, 2004; Masters and Brothers, 2002)
Galago 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. (Butynski, 2004; Masters and Brothers, 2002)
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.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
uses sound to communicate
Referring to an animal that lives in trees; tree-climbing.
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.
uses smells or other chemicals to communicate
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
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.
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
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.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
an animal that mainly eats all kinds of things, including plants and animals
having more than one female as a mate at one time
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
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
Living on the ground.
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
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
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.
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.
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. 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.
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.
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'.