Galago thomasi
Thomas's bushbaby

The range of Thomas’s bushbabies extends from Cote d'Ivoire through Cameroon, Angola, and Congo-Zaire to Uganda, Tanzania, and Zambia, and possibly northern Kenya around Mount Marsabit. They may occur in several other African countries but due to recent taxonomic changes this has yet to be clarified. ("The IUCN Red List of Threatened Species", 2008; Groves, 2001; Perkin and Bearder, 2004)

Thomas’s bushbabies are found in a variety of different habitats, including primary and secondary forests, marshy areas, gallery forest, savanna, and open woodlands such as miombo. They inhabit both lowland forests and highland forest and wooded areas up to 2000 meters. ("The IUCN Red List of Threatened Species", 2008; Rowe, 1996)

Thomas’s bushbabies are brownish-grey with grey underparts, prominent dark eye patches, narrow faces, and dark rostra. Thomas’s bushbabies resemble Prince Demidoff’s bushbabies (Galago demidoff). Although not typically visible in the field, a distinguishing feature is the genital morphology of Thomas’s bushbabies, which differs from all other members of the Galagidae family. The body length of Galago thomasi averages 146 mm, with a range of 123 to 166 mm, tail length averages 261 mm, ranging from 150 to 233 mm. Thomas’s bushbabies weigh, on average, 99 g, but varies in weight from 55 to 149 g. Males are larger than females. (Rowe, 1996)

The lifespan of Galago thomasi is not reported in the literature. The closely related Galago demidoff has been known to live 13 years in the captivity. (Rowe, 1996)

Thomas’s bushbabies are both nocturnal and arboreal. They spend much of their waking time foraging solitarily. They inhabit higher levels of the forest, usually above 20 meters. After foraging for the night individuals usually come together in the early morning hours before dawn. They have been found sleeping together as well. Group dynamics are considered complex, but groups are highly dispersed during foraging periods. They have been observed allogrooming when meeting one another and they make many postural motions with their bodies. Compared to Galago matschei, G. thomasi uses arboreal quadrupedalism more, although both species make much use of leaping. Thomas’s bushbabies primarily use small, oblique, mid-canopy branches. In Kibale Forest, Uganda, Thomas’s bushbabies were reported nesting in the night nest of a common chimpanzee Pan troglodytes, despite the fact that chimpanzees regularly prey upon galagos. (Macdonald, 2001; Off and Gebo, 2005)

Home Range

Home range size in Thomas’s bushbabies is not known. In another species, Galago demidoff, the home range was found to be 0.6 to 1.4 ha. (Rowe, 1996)

The facial markings of the different species in the family Galagidae may help them distinguish one individual from another when they come into contact. Galago thomasi individuals use chemical cues extensively. They have a scent gland near the anal region that is used in scent marking to communicate with conspecifics. They also urinate on their cupped hands, then spread the urine on their feet, so it is spread when they walk. This behavior, urine-washing, is more frequent in males than females, and is carried out in a variety of situations. Thomas’s bushbabies also have species-specific calls: they have a rolling call that rises to a crescendo and is then repeated several times. These calls can be used to communicate position to one another as well as to indicate mood. Tactile communication takes the form of nose-to-nose sniffing then nose-to-face contact when conspecifics first encounter each other. They also reciprocally lick each other, depositing saliva and sometimes urine. ("Thomas's Galago (Galago thomasi)", 2007; Macdonald, 2001)

Like other galagos, Thomas’s bushbabies eat a variety of foods, but are primarily insectivorous. They consume small vertebrates and insects, fruit, tree buds and leaves, as well as tree gums. They use their large ears to listen for insects and small vertebrates and have been known to catch insects in mid-air. ("Thomas's Galago (Galago thomasi)", 2007; Macdonald, 2001; Rowe, 1996)

Because of their small size, Thomas’s bushbabies are likely to be preyed on by nocturnal predators such as small carnivores and owls. During the daytime, even though they sleep in small tree hollows or crevices, galagos are not always safe from predators. Common chimpanzees Pan troglodytes have been observed using a stick as a spear in order to reach a sleeping Galago demidoff in its nest and it seems likely they would prey upon G. thomasi as well. Arboreal snakes may also be a threat. ("Predation on Mammals by the Chimpanzee", 1997; Macdonald, 2001)

Thomas’s bushbabies help to disperse seeds of the fruits that they eat. They also presumably serve as prey for smaller forest carnivores and regulate arthropod communities through their predation. Trypanosomes have been found in the blood of Thomas’s bushbabies in Kivu Province, Democratic Republic of Congo. ("Predation on Mammals by the Chimpanzee", 1997; Van Den Berghe and Peel, 2007)

There are no known negative impacts of Thomas’s bushbabies on humans.

Thomas’s bushbabies do not play any major economic roles for humans. They may provoke some interest by ecotourists, but they are active at night and rarely observed.

The IUCN lists Galago thomasi as lower risk/least concern. This status is due to their adaptability to different types of environments rather than reliance on primary and secondary rainforests that are being destroyed by humans in Africa for agriculture. With education both for the local people where the animals live and educating the general public on the importance of natural ecosystems Galago thomasi may be able to stay listed as lower risk least concern. ("The IUCN Red List of Threatened Species", 2008)