Galagidaebushbabies and galagos(Also: dwarf bushbabies and dwarf galagos)

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These African primates are small, quick animals that are still relatively common in many areas. The family contains 4 genera and 11 species. It is often associated with -- and sometimes included as a subfamily within -- the Lorisidae (which, to make matters more confusing, is also sometimes known as Loridae).

Galagos and bushbabies have long hindlegs (noticeably longer than their forelimbs) and a long tail. Their bodies are lightly built compared to the heavier lorisids. The ears are large and mobile. Their fingers are well developed but more slender than in lorisids. They have terminal disk-pads, and the pollux (thumb) is not opposable. In contrast to lorisids, galagos and bushbabies do not have retia mirabilia in their hind limbs. As in most other strepsirhines, their hind feet include a modified " toilet claw." Galagos move rapidly through the trees, leaping from branch to branch (up to 12 meters!). This also contrasts with lorisids, which move slowly and rarely leap.

The smallest member of this family weighs only around 60 g, while the largest may weigh up to 1.2 kg. Their fur is soft and woolly, darker on the dorsal surface than the ventral, and ranging from gray to brown.

The skulls of galagos and bushbabies are lightly built with a globular braincase and without strongly developed temporal ridges. The facial region is reduced. The orbits are directed more to the sides than in lorids. Their postorbital processes and zygomatic arches are slender, and the bullae are considerably inflated. Unlike lorids, the zygomatic branch of the squamosal lies entirely anterior to the external auditory meatus; and the palate usually ends behind the second rather than the third upper molar.

As in the case of most other strepsirrhines, galagos and bushbabies have a toothcomb made up of lower incisors and canines. Their molars are similar to those of lorisids. The dental formula of bushbabies is 2/2, 1/1, 3/3, 3/3 = 36.

Male galagos have a baculum, a structure that male lorisids lack.

Galago and bushbaby species vary in food habits from being highly insectivorous to eating leaves, fruit, or gums secreted by trees. Some forage low in undergrowth; others are seen mainly in the canopy. The hands and feet of some species appear to be specialized for grasping small twigs and branches. Most of their activity is nocturnal; during the day, they can be found in thick vegetation or hollow trees.

As far as is known, galagos and bushbabies live in small groups of 7 to 9 individuals, but only a few species have been studied. Scent, vocalizations, and facial expressions all play a role in social communication.

Technical characters

Literature and references cited

Feldhamer, G. A., L. C. Drickamer, S. H. Vessey, and J. F. Merritt. 1999. Mammalogy. Adaptation, Diversity, and Ecology. WCB McGraw-Hill, Boston. xii+563pp.

Groves, C. P. 1989. A Theory of Human and Primate Evolution. Oxford Science Publications, Clarendon Press, Oxford. xii+375 pp.

Nowak, R.M. and J.L. Paradiso. 1983. Walker's Mammals of the World, Fourth edition. John Hopkins University Press, Baltimore, London.

Szalay, F. S., and E. Dodson. 1979. Evolutionary History of the Primates. Academic Press, New York. xiv+580 pp.

Thorington, R. W., Jr., and S. Anderson. 1984. Primates. Pp. 187-216 in Anderson, S. and J. K. Jones, Jr. (eds). Orders and Families of Recent Mammals of the World. John Wiley and Sons, N.Y. xii+686 pp.

Vaughan, T. A., J. M. Ryan, N. J. Czaplewski. 2000. Mammalogy. Fourth Edition. Saunders College Publishing, Philadelphia. vii+565pp.

Wilson, D. E., and D. M. Reeder. 1993. Mammal Species of the World, A Taxonomic and Geographic Reference. 2nd edition. Smithsonian Institution Press, Washington. xviii+1206 pp.

Contributors

Phil Myers (author), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

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

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.

motile

having the capacity to move from one place to another.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate