Otolemur crassicaudatus
Greater Galago
Afrikaans : Bosnagaap
The thick-tailed bushbaby is the largest (length, including tail, 73 cm : mass 1,2 kg) of the three galago, or bushbaby, species which occur in southern Africa: the other two are the lesser bushbaby and Grant's bushbaby. Their heads are small for their bodies, and are rounded with huge eyes and large, labile, sensitive ears. There is a large colour variation, but they are predominantly grey, tinged with brown. The bushy tail is usually lighter than body. The throat and belly are a lighter grey. Their fur is long, fine and soft. Bushbaby's groom themselves before setting out at night by using their lower front teeth for combing, the long thin tongue for preening and the claw on the second digit of each hind foot for scratching.
They are sporadically active throughout the night, although they have periods of inactivity, and one of these appears to be around midnight. They wash the soles of their feet with urine: this assists in marking territory, as well as making their feet more adhesive for tree-climbing purposes. In the daytime, the bushbaby rests among thick foliage high above the ground; a habit that makes it vulnerable to fires.
The thick-tailed bushbaby has good sight, scent and hearing, and is well adapted to its habitat of trees. The sense of smell is useful for distinguishing tracks and territorial boundaries, which are marked with a secretion from glands in the middle of the chest. The ears are large and can be moved independently of each other. They often furl and unfurl their ears giving them a quizzical expression. The eyes are forward pointing and large. As with most galago species, there are flat disks of thickened skin at the ends of the fingers and toes useful in grasping limbs. The fingers are long, and the toes are flattened with flattened nails. Their good hearing not only helps warn this bushbaby of approaching owls and other predators, but it assists the creature to detect the delicate sounds of its own animal prey, which consists of lizards and small birds.
They form relatively stable groups, sleeping alone or in groups of 2 - 6, and then foraging at night either solitarily or in these groups. Groups may have up to 12 resting places within their home ranges. They are alert and agile, making leaps of up to 2 meters. They sleep in nests that are 5-12 meters off the ground. Adults sleep together during the day, but split up at night to forage. They have been found to move up to 1 kilometer through the night.
The composition of the group varies. It could be an adult pair with young, two adult females with young, or one adult female with young. The adult males are territorial and they seek home ranges that overlap several female home ranges.
Gender differences:
The males are significantly larger than females. The average body mass for the greater galago is around 1.2 kilograms for females and 1.4 kilograms for males.
Habitat:
The thick-tailed galago, or bushbaby, is found in East Africa from southern Sudan to eastern South Africa and through southern Angola. They live in forests and woodlands, including eucalyptus and other plantations ,from sea level up to 1 800 m.
Diet:
The thick-tailed bushbaby is mostly vegetarian: they eat fruit, nuts, leaves and the gum of certain trees; but they also eat a fair proportion of insects and other invertebrates, and occasionally even reptiles and birds. In a study in South Africa, approximately 62% of their diet was gums, supplemented by fruits and insects.
Reproduction:
The birth season of the thick-tailed galago varies according to locality, ranging from August to November. The female estrous cycle lasts approximately 44 days and gestation is 133 days. The young are born in nests which are relined with fresh green leaves and twigs shortly before their birth. Litter size is generally 2 individuals but can be 3. During the early part of their lives the mother will carry them in her mouth. Females produce a rich energy-dense milk. Suckling and carrying cease after about 10 weeks and the young move independently after 17 weeks. Females reach sexual maturity at 2 years of age.
Other:
Predators of the greater galago include leopards, eagle owls, snakes and genets.
The bushbaby's call is a harsh and repetitive wail which resembles the squalling of a baby in a tantrum. It is this sound that gives the bushbaby its name. It utters the call from tall trees and the body shakes rapidly while emitting the call This call is uttered most often during the mating season and is used for long distance communication.
The thick-tailed bushbaby is more than twice as large and eight times heavier then the lesser bushbaby; it has a more pointed face and a longer, bushier tail.
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