It is easy to underestimate Tanzania’s primate diversity, which stands at around 20 species, including bushbabies. This is because most primates are essentially arboreal, and are thus better adapted to forested habitats than to the savannah country focussed on by most safaris. Even so, it is possible to see half-a-dozen primate species on a standard northern circuit safari, and enthusiasts might also want to travel to the Lake Tanganyika region, where Gombe Stream and Mahale Mountains support western rainforest primates, including populations of habituated chimpanzees.
Mangabeys & allies
This unmistakeable black ape is essentially a West African forest species, but its range extends to the eastern shore of Lake Tanganyika, where Jane Goodall initiated her celebrated behavioural study in 1960. Although Tanzania supports a relatively small population of around 2,000 chimps, it offers the best opportunity anywhere to track then in the wild.
- Chimps and humans are more closely related to each other than to any other living creatures. They share 97% of their genes, and taxonomists place them both in the family Hominidae.
- Chimpanzees live in extended communities of up to 100 individuals, which roam the forest in small subgroups. Males stick with their birth community, but post-adolescent females often emigrate.
- The common notion of chimps as strict vegetarians was rocked when Jane Goodall witnessed them hunting monkeys in Gombe Stream. This is now known to be a regular occurrence in the dry season.
Viewing tip: First contact is usually aural, in the form of the ‘pant-hoot’ call, which consists of several chimps hooting in exited unison, rising to frenzied crescendo before abruptly fading away.
Top sites: Gombe, Mahale and less reliably Rubondo Island.
The most terrestrial of primates, baboons, can be distinguished from other monkeys by their greater bulk (up to 45kg), inverted U-shaped tail and doglike head. Two species are present in Tanzania: the bulkier green-brown olive baboon of the northwest and the slighter yellow-brown yellow baboon of the south and east. Both are versatile omnivore, and are at home in almost any habitat other than desert or rainforest interiors.
- Baboons live in large, busy, socially complex troops characterised by rigid matriarchal lineages. Males regularly move between troops to in a bid to improve their social ranking.
- When baboons start to see people as a food source, which occasionally happens in the vicinity of lodges and campsites, they can become very aggressive and should be treated with great caution.
- Baboons don’t only look rather doglike – their loud alarm call (often indicating the presence of a leopard or lion) is reminiscent of an angry bark.
Viewing tip: Baboons seldom generate the interest they deserve – anybody who has sat watching a troop for an hour or two will know how rewarding it can be in terms of observing animal interaction.
Top spot: Gombe and Manyara for interaction, but they are present in most other national parks.
The thumbless forest-dwelling colobus monkeys have a rather streamlined appearance, created by their small heads, very long tails and spidery limbs. Strongly arboreal, they seldom venture to the ground and subsist almost entirely on leafy leguminous matter, processed by a ruminant-like digestive system.
- The acrobatic black-and-white colobus has a luxuriant black coat with bright white facial and flank markings and a flowing white tail that streams behind it spectacularly when it leaps between trees. It is typically seen in parties of up to 10 adults, sometimes with a couple of albino-like babies in tow. A resident of highland and mid-altitude forests, it is regularly observed in Arusha, Kilimanjaro and the Serengeti’s western corridor.
- Similar in appearance but with a less flowing tail, the Angola colobus inhabits forested habitats along the Indian Ocean coastline and the Eastern Arc Mountains. Mahale supports an endemic race. It might be seen in Amani, Udzungwa and (with greater effort) Mahale.
- The Central African red colobus is a widespread but nondescript rainforest species whose range extends to the eastern shores of Lake Tanganyika, where it is sometimes hunted by chimps in Mahale and Gombe.
- Kirk’s red colobus, distinguished by its unkempt white crest (recalling a colobine Einstein), is endemic to Zanzibar Island. This endangered species can be observed closely in Jozani Forest Reserve, the main stronghold for the estimated population if 2,000.
- The critically endangered Iringa red colobus is endemic to the Udzungwa Mountains and probably numbers no more than 1,000 in the wild.
The guenons of the genus Cercopithecus are the most diverse of the check-pouch monkeys, a family that also includes baboons and mangabeys (but not colobuses). All members of this family possess an inner cheek pouch, and certain species can holds as much food in this pouch as they can in their stomach. Guenons are a more varied bunch than the colobus monkeys, and occupy a greater range of ecological niches, from dry savannah and montane moorland to evergreen forest.
- The vervet monkey is the world’s most numerous primate, apart from humans. It a familiar sight on African safaris, with its grizzled olive-grey coat offset by a black face, white ruff, pale belly and show-off blue scrotum. An adaptable and gregarious omnivore, it might be seen in any habitat other than desert and forest. It is generally unmistakeable, though in it does occur alongside the more spindly and russet patas monkey in the northern Serengeti.
- The blue (or Sykes’) monkey is the most widespread forest guenon, reflecting its willingness to follow riverine woodland and similar corridors through savannah habitats. It live in small troops, and has a uniform dark blue-grey coat broken by a white throat. Reliable spots include the forested slopes of Ngurdoto Crater (Arusha), and the groundwater forest in Manyara.
- The red-tailed monkey is a western forest species with a coppery tail and a distinctive white nose-blob. Its occurs in Gombe or Mahale on the eastern shores of Lake Tanganyika, where it might be seen singly or in pairs, though larger groups might congregate at seasonal food sources.
Smaller than baboons but larger than guenons, mangabeys are dull arboreal monkeys associated primarily with low-altitude rainforest in central Africa. Tanzania supports one very localised endemic species in the form of the Sanje crested mangabey, which was unknown to science until 1979. Unique to the Udzungwa Mountains, it is thought to number around 2,000 in the wild.
Remarkably, two populations of a previously undescribed grey-brown monkey were discovered in southern Tanzania in 2003. Originally thought to be a type of mangabey, this shaggy and exclusively arboreal monkey is now assigned to a monotypic genus, the first primate discovery of comparable magnitude in 83 years. Known by its local name of kipunji, it is thought to number about 500 in the wild, split between Mount Rungwe and Udzungwa.
Seldom observed due to their nocturnal habits, the bushbabies (or galagos) are more closely related to the lemurs of Madagascar than to the monkeys and apes of the African mainland. They are endearing creatures, with wide round eyes, agile bodies and peculiar skinny fingers. Two species are widespread in the Tanzania: the 1kg greater galago, which emits a terrifying scream that you could be forgiven for associating with a misplaced chimpanzee, and the 150g lesser galago, which is also heard more often than its seen. Both species might be picked out by spotlight on night drives. Several localised forest galagos also occur in Tanzania, many of them recent discoveries.