Greystoke Mahale Camp Primates of Mahale Mountains National Park, Tanzania

Thomas M. Butynski & Yvonne A. de Jong Drawings by Stephen Nash

May 2009

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Contents

Mahale Mountains National Park 5 Primates of the Mahale Mountains National Park 6 Greystoke Mahale Primate Walk 8

Southern Lesser Galago 10 Silver Greater Galago 15 Vervet Monkey 20 Silver Monkey 25 Red-tailed Monkey 30 Yellow Baboon 35 Angolan Colobus Monkey 40 Red Colobus Monkey 45 Robust Chimpanzee 50

Checklist, Primates of the Mahale Mountains National Park 57

Cover drawing: Ashy red colobus Procolobus rufomitratus tephrosceles.

Unless otherwise stated, all photographs were taken by Thomas M. Butynski and Yvonne A. de Jong in Mahale Mountains National Park. 3 4 Mahale Mountains National Park peak – Mt Nkungwe – is 2520 m above sea level. Mean annual rainfall at In 1985, the Mahale Mountains National Park became the 11th national park Greystoke Mahale Camp is roughly 1500 mm. There is one wet season of Tanzania. This Park was created for the purpose of protecting a part of (November – April) and one dry season (May – October). It rarely rains the Albertine (Western) Rift Ecosystem and its globally significant during June, July and August. Temperatures are highest during the wet biodiversity, in particular the primates, endemic fish and the mosaic of season. Average monthly maximum daily temperatures range from 25º C to 29º C. Average monthly daily minimum temperature range from about 18º C vegetation and habitat types. Mahale Mountains National Park is 1613 km² Mammals of Mahale Mountains National Park in size and is located on the eastern shore of Lake Tanganyika, about 130 to 21º C . km south of the town of Kigoma. The Park includes the Mahale Mountains, the pristine beaches of Lake Tanganyika and a sizable part of Lake The list of bird species known to occur with the Park stands at 355 (see Tanganyika itself (out to 1.6 km from the shoreline). Nomad’s Checklist of the Birds of Mahale Mountains National Park), while the list of mammal species now totals 81 (see Nomad’s Checklist of the Five main vegetation types are found in the Mahale Mountains National ). There are 1174 species of Park. About 75% of the Park is covered with ‘miombo’ woodland (which is plants known for the Park but the actual number present is thought to be at dominated by Brachystegia spp, Isoberlinia angolensis and Julbernardia least twice this. Many of the plant and animal species present in Mahale spp). Lowland evergreen forest (locally called ‘Kasoge’) covers the flat to Mountains National Park are threatened with extinction. As such, this Park is hilly area between Lake Tanganyika and the mountains (780 to 1300 m extremely important for their long-term survival. above sea level). Rivers and streams throughout the lower, drier, parts of the Park hold strips of riverine forest. The slopes of the mountains hold a mix of Primates of Mahale Mountains National Park bamboo Oxytenanthera abyssinica bushland and montane forest (which is The Order Primates is comprised of an interesting, charismatic, diverse and congesta, Macaranga capensis dominated by Podocarpus milanjianus , successful group of species that are, with few exceptions, confined to the and Croton spp). The highest areas (> 2300 tropics and subtropics. Primates occur in a wide variety of habitats, m above sea level) are covered by grassland and montane bushland. including forests, woodlands, savannahs and even deserts and mangroves. Bersama abyssinica, Nuxia There are about 175 species and subspecies of primates recognized for Lake Tanganyika is 780 m above sea level and is the longest (673 km) and Africa at this time. Tanzania is known to have 23 species of primates, second deepest (1470 m) lake in the world and, as such, holds about 17% of making it one of the most important countries in Africa for the conservation the world’s fresh water. A total of 128 species of fish are known for Lake of primates. Tanganyika. Of these, 96 % are found nowhere else, making Lake Tanganyika of great importance to the conservation of Africa’s fish species The main characteristics that make a primate a primate are: diversity. Although the terrain of Mahale Mountains National Park is flat to hilly near 1. Eyes that face forward for binocular vision. This enables depth perception the Lake, the interior is extremely rugged with numerous cliffs. The highest (three dimensional views).

5 6 2. A long period of development before and after birth. The mother invests smallest species of the Mahale primate community (the unidentified much time and energy in her (usually one) offspring and there is a long Galagoides sp.) weighs about 150 g, has a body that is about 150 mm long socialization period. and a tail that is about 230 mm in length. The largest species of primate at Mahale is the chimpanzee; adult males weigh about 42 kg and have a body 3. Large brain relative to body size. length of about 82 cm. Chimpanzees, being ‘apes’, have no tails. More than any other group of animals, it is the primates that make the Mahale 4. Fingers and toes that have flat nails (as opposed to claws). The skin of the Mountains National Park such a special and unique place. fingers and hands is hairless and has fingerprints. Greystoke Mahale Primate Walk 5. A shortened snout and, therefore, a reduction in the sense of smell. Besides ‘chimpanzee tracking’, Greystoke Mahale Camp offers ‘primate walks’ along trails that pass through the area’s various ‘primate hotspots’. 6. An opposable thumb that enables a precise, firm grip (although the The ‘Primate Walk’ (see map below) was designed primarily to increase the colobus monkeys do not have thumbs). chance of encountering the area’s two most difficult to find diurnal primates- --the silver monkey and the red colobus monkey---but also to take visitors In spite of the above ‘specialized’ features, anatomically, primates are through a diversity of forest types were a large number of species of birds, among the least specialized of today’s mammals. butterflies, wild flowers, trees, etc., can also be observed. A boat takes the visitors and their guides from Greystoke Mahale Camp to the Kasiha Primates play an important role in the survival of the natural habitats in TANAPA Camp (about a 10 minutes boat ride). From there the visitors walk which they live. For example, they comprise a high proportion of the slowly back to Greystoke Mahale Camp. The Primate Walk is about 5 km mammalian biomass in many habitats and are excellent dispersers of long and takes most visitors 4 to 5 hours to complete. This walk can be seeds. They are good indicators of the quality and health of an ecosystem, made shorter or longer if necessary. especially forest ecosystems. If primates were to disappear from the forest, the ecological community would greatly change and the viability of those forests would be seriously threatened. When forests are degraded or lost, humans loose numerous crucial benefits such as water catchment and soil protection, climate regulation, timber, firewood, foods and medicines. The diversity of primates in the Mahale Mountains is high, with at least 10 species of eight genera present. Nine of the species are profiled here. One kind of dwarf galago or bushbaby (Galagoides sp.) is present but has yet to be identified as to species. Mahale Mountains National Park has several major habitats, all of which support one or more species of primate. The

7 8 Southern Lesser Galago Galago moholi Kiswahili: Komba Kitongwe: Mung'anya

Taxonomy: The subspecies found in Mahale Mountains National Park is the moholi lesser galago Galago moholi moholi.

Photograph by Simon K. Bearder

Description: Medium-sized galago with white nose stripe. Ears large. Eyes orange. Body and tail mostly grey.

Body weight: Adult females = 155 (range 126 - 176) g. Adult males = 177 (range 145 - 212) g.

9 10 Distribution: From west Namibia, north into Angola and east through Botswana, Zimbabwe, Malawi, western and southern Tanzania, Mozambique, to northeastern South Africa.

Food: Eats mostly insects (insectivorous) and gum (gummivorous). They visit their favorite trees to forage by using specific trails which they mark with their scent. Their ears are mobile, eyes are big and they have a good sense of smell which helps to locate food.

Habitat: Mainly semi-arid, open woodland, riverine bush, scrub and forest fringe.

Abundance: From 13 to 31 individuals/km²

Activity pattern: Nocturnal and arboreal. They sleep alone or in small groups in tree holes or in dense and thorny bush.

Distance moved per night: About 2 km.

Size of area used (home range): Females: 4 to 12 ha. Males 9 to 23 ha.

Group size: From 1 to 3 individuals.

Age at sexual maturity: Females: 6 to 7 months. Males 10 to 11 months.

Gestation: 125 - 130 days

Birth weight: About 12 g

11 12 Social organization: Dispersed social network. The adult male’s territory Longevity: About 16 years. overlaps the territories of one to five adult females. Males leave their natal range to avoid inbreeding and sexual competition. Other: They are able to move rapidly through dense thorn bushes with ease.

Conservation status: Common and wide spread. Not threatened except locally.

Conservation threats: Major threat to this species is destruction of habitat.

Best viewing at Greystoke Mahale Camp: The southern lesser galago has not been encountered at Greystoke Mahale Camp. This species can be found in the woodlands of the lower Mahale Mountains.

Vocalizations: Since galagos are nocturnal and have limited vision, vocalizations are a highly important means of communication. Calls give information about location, sex, age, condition, behavioral intentions, etc. The southern lesser galago has at least 19 different calls. Males and females both produce loud calls (‘honks’) which can be in bouts that last for more than 1 hour and can be heard to a distance of > 200 m.

Predators: Small carnivores, birds (large owls) and large snakes. Photograph by Simon K. Bearder

13 14 Silver Greater Galago

Otolemur crassicaudatus Kiswahili: Komba Kitongwe: Mung'anya

Taxonomy: The subspecies found in Mahale Mountains National Park is the miombo silver galago Otolemur crassicaudatus monteiri.

Description: The largest galago (bushbaby). Muzzle robust and blackish. Ears large and pinkish inside. Silvery-grey above and off-white to grey below. Tail long, full, and silver-grey.

Body weight: Adult females = 1.1 kg (range 0.9 - 1.6) kg. Adult males = 1.3 kg (range 1.0 - 1.5) kg.

Distribution: South and east of the Congo Basin. Throughout most of Tanzania.

15 16 Food: Omnivorous. Eat mainly insects, fruit and gum. Individuals follow Activity pattern: Nocturnal and arboreal. Most active during the first few pathways to known food sources. hours after dusk and during the last few hours before dawn.

Habitat: Open woodland and savannah, especially miombo woodland. Also Distance moved per night: Unknown. in forests, thickets and well developed woodland of higher rainfall areas. Common sleeping sites are dense tangles of creepers and branches 5 to 12 Size of area used (home range): About 7 ha (one female with her young). m above the ground. At Greystoke Mahale Camp, this galago is most often seen and heard at night high in the oil palms. Group size: Often alone. Sometimes in small, dispersed, groups of two or three individuals. Mother with offspring, sometimes joined by an adult male Abundance: Locally common. at the sleeping site.

Age at sexual maturity: Females: 24 months. Males: 21 months.

Gestation: About 33 days.

Birth weight: About 40 g.

Social organization: Alone or in small, dispersed, groups. In areas where fruit is abundant, the young tend to stay longer with the mother. Young males disperse from the natal home range.

Vocalizations: Since galagos are nocturnal and have limited vision, vocalizations are a highly important means of communication. Calls give information about location, sex, age, condition, behavioral intentions, etc. The silver greater galago has a large number of different calls. The ‘loud call’ is as a series of complex, well-spaced, drawn out cries given at a constant rate. This call can be heard at a distance of at least 300 m.

Predators: Leopards, large owls, snakes, genets, chimpanzees and humans. Longevity: Live up to 15 years in captivity. Longevity in the wild is unknown.

17 18 Other: Territorial. The adult female occupies a territory with her offspring. Vervet Monkey Male territories are larger and overlap with those of females. Chlorocebus pygerythrus Conservation status: Common and widespread. Not threatened except Kiswahili: Tumbili Kitongwe: Ijanda locally. Taxonomy: The subspecies found in Mahale Mountains National Park the Conservation threats: There are no major threats to the survival of this russet-green vervet Chlorocebus pygerythrus rufoviridis. species. It may be locally threatened due to the loss of habitat.

Best viewing at Greystoke Mahale Camp: Most commonly seen and heard in the oil palms behind rooms 1, 2 and 3.

Description: Medium-sized monkey that is often on the ground. Olive-yellow above and white below. Face black with white cheek whiskers and brow, forming a ring around face. Hands, feet and tail tip black or blackish.

Body weight: Adult females = 4.1 (range 3.4 - 5.3) kg. Adult males = 5.5 (range 3.9 - 8.0) kg.

Distribution: Eastern and southern Africa. Over most of Tanzania.

19 20 Food: Omnivorous. Diet includes leaves, flowers, fruits, seeds, gums, invertebrates and, rarely, small vertebrates and eggs. Forages both in trees and on the ground.

Habitat: Savanna-woodlands and forest edges. Often close to watercourses, swamps, lakeshores and coast. Require a source of drinking water and tall trees in which to sleep.

Abundance: Widespread but patchily distributed. Usually occurs at densities of about 10 to 100 individuals/km².

Activity pattern: Diurnal. Most active during the first few hours after dawn and during the last few hours before dusk. The hottest hours of the day are usually spent resting. About 30 to 40 % of the time is spent feeding and about 15 to 20 % of the time is spent moving.

21 22 Distance moved per day: From 135 to 2558 m. Conservation status: Common and widespread. Not threatened except locally. Vervets occupy a wide range of habitats. Nonetheless, they are often Size of area used (home range): From 5 to 103 ha. patchily distributed due to their need to drink water and for suitably tall trees in which to sleep. Group size: Typically number 6 to 47 individuals. Conservation threats: Populations are declining in many regions, particularly Age at sexual maturity: Females: 4 years. Males: 5 to 6. where habitat change (including degradation of woodlands, water depletion and human encroachment) is taking place. Gestation: About 156 to 161 days. Best viewing at Greystoke Mahale Camp: One group visits camp on a daily Birth weight: 300 to 400 g. basis and sleeps regularly in the oil palms behind the buildings. They are often seen and heard foraging in the oil palms on the forest edge (with the Social organization: Multi-male, multi female groups. Males leave the natal beach) during the day. Vervets are not found deep in the forest like the other group once sexually mature. Females stay in their natal group. Females and monkeys. males both maintain dominance hierarchies within the group. Daughters tend to occupy a rank near their mothers rank.

Vocalizations: Vervets produce at least 33 different vocalizations. Different alarm calls are used to identify different species of predators. The loud threat-alarm bark is given by adult and sub adult males and can be heard to at least 400 m.

Predators: Leopards, crowned eagles, martial eagles, pythons, yellow baboons and humans. Chimpanzees hunt vervet monkeys in the Mahale Mountains.

Longevity: At least 18 years in the wild.

Other: Vervets commonly live along narrow strips of suitable habitat near water sources and, therefore, no groups border the home ranges of more than two other groups.

23 24 Silver Monkey

Cercopithecus mitis Kiswahili: Kima Kitongwe: Nkima

Taxonomy: The taxonomy for this species is under debate. The subspecies found in Mahale Mountains National Park remains to be determined. This subspecies belongs to a group of monkeys that is commonly referred to as the ‘blue monkeys’.

Description: Medium-sized, arboreal monkey. Back silvery grey. Top of head, outer limbs, and tail blackish. Grey below.

Body weight: Adult females = 3.9 (range 2.3 - 5.3) kg. Adult males = 5.8 (range 3.7 - 7.8) kg.

Distribution: Widespread across tropical Africa and over south-east Africa. The most widely distributed forest monkey in Africa. Present in most of Tanzania’s forests.

25 26 Food: Omnivore. Main foods are fruit (ca. 40 %) and invertebrates, but also Distance moved per day: Average about 1100 m (range 500 - 1900 m) eats leaves, flowers, stems, galls, bark, gum, fungi and, occasionally, eggs and small vertebrates. Foods are fermented in both the fore- and the hind- Size of area used (home range): Typically 15 to 25 ha (range 8 - 253 ha). gut which gives this monkey dietary flexibility. Ranges overlap with neighboring groups. Home range overlap can be up to 98 % in high-density populations. Habitat: In primary and secondary moist lowland, mid-altitude and montane forest. Also riverine, swamp and coastal forests. Group size: Typically 10 to 25 individuals (range 3 - 65).

Age at sexual maturity: Females 6.5 years. Males 6 - 8 years.

Gestation: About 176 (162 - 190) days.

Birth weight: 400 to 700 g.

Social organization: Single-male, multi-female groups. Females remain in their natal group while sexually mature males leave the natal group.

Vocalizations: The vocal repertoire comprises at least 10 different calls. The adult male gives three loud calls: the resonant ‘boom’, given in response to varying disturbances; the ‘pyow’, 3 to 7+ sequences given as an intergroup spacing call and during intergroup encounters; and the ka-train, given most often in alarm to predators, especially crowned eagles. The ‘pyow’ is the loudest call and can be heard to a distance of about 1 km.

Predators: Crowned eagles, leopards, pythons, humans, domestic dogs and chimpanzees. Abundance: Usually from 7 to 153 individuals/km².

Longevity: About 20 years. Activity pattern: Diurnal and arboreal. Most active during the first few hours after dawn and during the last few hours before dusk. Tends to rest during Other: Territorial. Males compete for females by taking over groups as the the middle hours of the day. sole resident (‘harem’) male. Non-resident males on the periphery of the

27 28 group sometimes ‘sneak’ copulations. Also, there may be temporary multi- Red-tailed Monkey male influxes into groups during the breeding season. At Mahale, silver monkeys avoid baboons and chimpanzees but frequently associate with Cercopithecus ascanius red colobus and red-tailed monkeys. Kiswahili: Nyani mwenye mkia mwekundu Kitongwe: Ndugulugu

Conservation status: Common and widely distributed. Not threatened Taxonomy: The subspecies found in Mahale Mountains National Park is except locally. Schmidt’s red-tailed monkey Cercopithecus ascanius schmidti

Conservation threats: Degradation, destruction and fragmentation of forests. Many forests have been extensively logged and are now secondary forest. The silver monkey is able to survive, at least at low density, in these disturbed forests (better than most monkeys).

Best viewing at Greystoke Mahale Camp: Shy and often hard to observe in the Mahale Mountains. Not found in the immediate vicinity of Greystoke Mahale Camp. Occurs over much of the forest but most readily observed near the Kansyana Research Camp (see Primate Walk Map, page 9).

Description: Medium-sized, arboreal monkey with a heart-shaped, white nose spot. Upper parts brown. Under parts cream. Tail mostly reddish.

Body weight: Adult females = 2.8 (range 2.1 - 3.8) kg. Adult males = 3.7 (range 3.0 - 4.8) kg.

29 30 Distribution: Across equatorial Africa from the Atlantic Ocean to western Kenya and western Tanzania. Mahale is on the south-eastern extreme of the range of this species.

Food: Depends on fruit (35 to 61 % of diet) and insects (14 to 31 % of diet). Other foods are leaves, flowers, nectar, stems, gum, bark, fungi and small vertebrates. Raid crops in some areas.

Habitat: Occurs in moist lowland, mid-altitude and montane forests, as well as in swamp, gallery and lakeshore forests. Able to live in secondary forest.

Abundance: Usually from 10 to 184 individuals/km². In the Mahale Mountains, about 116 individuals/km² in the forest and about 63 individuals/km² in woodland.

31 32 Activity pattern: Diurnal and arboreal. Forages and feeds 26 to 69 % of the Other: Territorial. Groups often form mixed-species (‘polyspecific’) day (feeding peaks in early morning and later afternoon), rests 9 to 59 % associations with other primate species (especially red colobus and silver and spends 1 to 8 % of the day in social behaviours. monkeys). Distance moved per day: From 1 and 2 km. Conservation status: Common and widespread. Not threatened except locally. Size of area used (home range): From 15 to 67 ha. Conservation threats: Major threats are habitat degradation and loss due to Group size: Typically 25 to 35 individuals (range 3 - 50). agriculture and forest exploitation.

Age at sexual maturity: Females about 4 years. Males about 6 years. Best viewing at Greystoke Mahale Camp: One group is often found between the office area and the mess tent. Frequently encountered during Gestation: Not known, but estimated to be about 5 months. chimpanzee viewing walks.

Birth weight: About 260 g

Social organization: Single adult-male, multi-female groups. Females remain in their natal troop while sexually mature males leave the natal group. Males leave natal group as sub-adults (> 4 years old).

Vocalizations: The vocal repertoire contains at least eight different calls. Adult males give three loud calls; ‘pop’, given during group disturbances or in response to other loud noises; ‘ka’, a low-pitched call given singly or in a rapid sequence of 2 to 7 calls; ‘ka train’, a response to predators, especially crowned eagles.

Predators: Crowned eagles, leopards, chimpanzees and humans.

Longevity: About 20 years.

33 34 Yellow Baboon Papio cynocephalus Kiswahili: Nyani Kitongwe: Nguje

Taxonomy: The subspecies found in Mahale Mountains National Park is the kinda yellow baboon Papio cynocephalus kindae.

Description: Large monkey that is often on the ground. Yellow-brown above and off-white below. Muzzle long and black. Bare pink skin around eyes.

Body weight: Adult females 13 (range 11 - 15) kg. Adult males 25 (range 22 - 30) kg.

Distribution: Occurs from Somalia southwards through eastern Kenya, most of Tanzania to the Zambezi Valley, then west through southern Democratic Republic of Congo and Angola to the Atlantic Ocean.

35 36 Food: Omnivorous. Eats seeds, fruits, flowers, grasses, tubers, shoots, fungi, Activity pattern: Diurnal and semi-terrestrial. Most active during the first few lichens, invertebrates (including termites, beetles), birds, bird eggs and hours after dawn and during the last few hours before dusk. Spends much small vertebrates (including infant antelope and galagos). Probably the time foraging on the ground but climbs well. Sleeps in the tallest available most eaten food at Mahale is the fruit of the oil palm---a common tree left trees and on cliffs. over from the days when humans lived in the area. Baboons and chimpanzees compete over some foods at Mahale (such as mangoes and Distance moved per day: From 8 to 10 km. guava fruits). Baboons take food from twice as many plant species as do chimpanzees and, unlike chimpanzees, are able to digest unripe fruits. Size of area used (home range): About 24 km².

Habitat: Miombo (Brachystegia) woodland, dry bushland, thicket, forest Group size: Typically number 30 to 80 individuals but which may reach 300 edge and mangroves. Seldom found deep (> 1 km) within forests. Persists in animals. secondary and/or fragmented habitats, including cultivated areas. Require a source of drinking water and tall trees or cliffs on which to sleep. Age at sexual maturity: Females about 4.5 years. Males 7 to 8 years. Males leave the group at about 8.5 years of age. Abundance: In the Mahale Mountains, 10 individuals/km² in forest and 80 individuals/km² in woodland. Gestation: About 6 months.

Birth weight: From 900 to 1000 g.

Social organization: Multi-male, multi-female groups. Females remain in their natal group. Sexually mature males leave their natal group. Females and males both maintain dominance hierarchies within the group. Mating success of the male is related to his dominance rank.

Vocalizations: Vocal repertoire includes at least 10 calls, including ’grunts‘ (during foraging) and ’screams’ (agonistic interactions). Adults produce the loud ‘wahoo’ contact call which can be heard to at least 1 km.

Predators: Leopards, lions, spotted hyenas, crocodiles, eagles, pythons, chimpanzees and humans. Chimpanzees hunt and eat baboons at Mahale. At Gombe chimpanzees hunt and eat olive baboons Papio anubis.

37 38 Longevity: Up to 27 years in the wild. Angolan Colobus

Other: Females show distinctive estrus swellings that are related to their Colobus angolensis reproductive state. Not territorial. Kiswahili: Mbega Kitongwe: Ndugurugu

Conservation status: Common and widespread. Not threatened except locally.

Conservation threats: Baboons crop-raid and forage in areas populated by humans. They are, therefore, treated as vermin in some areas and have become locally extinct. They have been displaced by intensive agriculture in many places.

Best viewing at Greystoke Mahale Camp: One group visits camp on a daily basis and sleeps regularly in the oil palms behind the buildings. Often seen and heard foraging on the beach and in the vegetation around the buildings.

Diani Beach, Kenya

Description: Medium size black-and-white arboreal monkey with long white hair on the cheeks and shoulders (‘epaulettes’).

Body weight: Adult females = 7 (range 5 - 8) kg. Adult males = 9 (range 6 - 12) kg.

Distribution: Found only in Equatorial Africa from northern Angola eastwards to the montane and coastal forests of Tanzania and Kenya. Present on the ridges of the northern Mahale Mountains.

39 40 Food: Primarily eats leaves and seeds, but also fruit, flowers and lichens.

Habitat: Restricted to forests and forest fragments. In the Mahale Mountains, this species is confined to the moist montane forests of the higher ridges.

Abundance: From 4 to 31 individuals/km²

Activity pattern: Diurnal and arboreal. Typically, feeding starts at sunrise and continues until mid-morning, followed by a period of rest and another bout of feeding in the late afternoon until dusk.

Distance moved per day: From 300 to 1900 m.

41 42 Size of area used (home range): From about 20 ha to > 400 ha. Best viewing at Greystoke Mahale Camp: None within a long day’s walk of Greystoke Mahale Camp. Can only be seen by making the long trek to the Group size: From 3 to 50 individuals. Groups of about 30 individuals on Mt highest ridges of the Mahale Mountains, including Mt. Nkungwe, and Nkungwe, Mahale Mountains. camping near the site.

Age at sexual maturity: Females: 5 to 6 years. Males 7 years.

Gestation: 24 weeks.

Birth weight: Not known, but estimated to be 450 g.

Social organization: Multi-male, multi female groups. Females remain in their natal troop while sub-adult males leave the natal group.

Vocalizations: Adult males produce a roaring call as part of a display and during agonistic encounters among males. The ‘roar’ can be heard to a distance of about 1 km.

Predators: Crowned eagles, leopards, chimpanzees and humans.

Longevity: About 36 years in captivity but likely much less in the wild.

Other: Commonly associate with silver monkeys, red-tailed monkeys and red colobus, and respond to their alarm calls.

Conservation status: Common at many sites but the population in the Mahale Mountains is small, occupying an area of < 50 km². Not threatened in Mahale but locally threatened at many other sites. Mrima Hill, Kenya

Conservation threats: Habitat degradation, loss and fragmentation as a result of forest exploitation and clearing for agriculture.

43 44 Red Colobus Procolobus rufomitratus Kiswahili: Mbega Kitongwe: Ndugurugu

Taxonomy: The subspecies found in Mahale Mountains National Park is the ashy red colobus Procolobus rufomitratus tephrosceles.

Description: Medium size arboreal monkey. Top of head rusty-red. Upper parts blackish. Underside light grey to off-white.

Body weight: Adult females about 6 kg. Adult males about 11 kg.

45 46 Distribution: Central and East Africa. In Tanzania, this species is Activity pattern: Diurnal. Feed throughout the day but most of the present in only a small number of areas in the western extreme of the feeding is early and late in the day. About 45 % the daylight time spent country. Mahale Mountains is close to the south-eastern extreme of feeding, alternating with periods of rest and travel. the range of this species. Distance moved per day: From 180 to 1185 m. Food: Folivorous (leaf-eater). Young leaves dominate the diet. Petioles (the stem at the base/bottom of a leaf which attaches to a twig or Size of area used (home range): From 40 to 60 ha in the Mahale branch) of mature leaves are also often eaten. Unripe fruits, flowers Mountains, and from 35 to 100 ha elsewhere. and bark sometimes eaten. A preferred food in the Mahale Mountains are the young leaves of ‘padouk’ (Pterocarpus tinctorius). Group size: Usually 8 - 82 individuals. Most groups in the Mahale Mountains are comprised of 30 to 50 animals. Habitat: In a variety of forest types, including gallery forest, miombo woodland, lowland forest, mid-altitude forest and montane forest. Able Age at sexual maturity: About 5 years both for males and females. to live in secondary forests and in raphia palm swamps. Red colobus of the Mahale Mountains are in all of the major habitat types present Gestation: Between 6 and 7 months in the Park, from the shores of Lake Tanganyika up to the higher altitudes. Birth weight: Unknown but probably 400 to 500 g.

Abundance: Densities range from 25 to 300 individuals/km². Present Social organization: Multi-male, multi-female groups. Males remain in at 80 to 105 individuals/km² in the Mahale Mountains forests and at 27 their natal group while sexually mature females transfer from their individuals/km² in the woodlands. natal group. Males maintain a dominance hierarchy and form coalitions.

Vocalizations: The vocal repertoire is complex and may contain more than 25 different calls. Unlike other monkeys in the Mahale Mountains, red colobus do not have a loud call.

Predators: Crowned eagles, leopards, chimpanzees, and humans. Chimpanzee predation on red colobus varies greatly among sites and over time, with from 1 % to as much as 40 % of red colobus killed during some years. In the Mahale Mountains, the annual kill rate of

47 48 red colobus by chimpanzee varies from 1 to 4 %. This rate is similar to Robust Chimpanzee the annual replacement rate within this population of red colobus. Pan troglodytes Longevity: Unknown, but wild individuals live to at least 20 years of Kiswahili: Sokwe Kitongwe: Ikuku age. Taxonomy: The subspecies found in Mahale Mountains National Park Other: Females have estrus swellings that are related to their is the eastern robust chimpanzee Pan troglodytes schweinfurthii. reproductive state. Not territorial. Home ranges of groups often overlap, sometimes extensively.

Conservation status: An ‘Endangered’ species. Ashy red colobus are common in some areas, including Mahale Mountains National Park, but rare at some sites and inexplicitly absent from many of East Africa’s forests. The subspecies of red colobus in Tana River Primate National Reserve, Kenya, P. r. rufomitratus, is ‘Critically Endangered’. Red colobus are sensitive to habitat degradation and hunting. Therefore, healthy populations of red colobus generally indicate healthy forest ecosystems.

Conservation threats: The most serious threats are habitat degradation, loss and fragmentation due primarily to clearing for agriculture and the extraction of forest products by local people. A Description: Large, robust ape. Ears and face hairless. Pigmentation of threat to populations which co-exist with chimpanzees is predation by facial skin ranges from pale brownish-pink to brown to grayish-black. chimpanzees. Body covered with medium-long grey, blackish, or black hair. Tail Best viewing at Greystoke Mahale Camp: Groups can be seen absent. Walks on knuckles of hands. throughout the Park, but are most readily seen in the vicinity of Kansyana Research Station (see Greystoke Mahale Primate Walk). Body weight: Groups are often encountered close to chimpanzees. Adult females = 42 (range 28 - 56) kg. Adult males = 34 (range 20 - 46) kg.

49 50 Food: Omnivorous. About 60 % of the diet is ripe fruit. Leaves and piths are major supplemental foods, particularly during months of low ripe fruit availability. Other food items are unripe fruit, seeds, flowers, bark, wood, shoots, sap, honey, insects, eggs and vertebrates. Red colobus is the most often hunted prey but black–and-white colobus, silver monkey, red-tailed monkey, baboon, vervet, galago, bushbuck, florida bushpig, suni, duiker, mongoose, hyrax, birds, rodents and tadpoles are also eaten. Hunting of the larger mammals is undertaken almost exclusively by parties of adult males.

In the Mahale Mountains, chimpanzees have thus far been recorded to consume 198 species of plants. They depend largely on saba Saba fruits (a liana), which is available in high densities from August to January. About 20 % of their annual feeding time is spent eating saba fruits.

Chimpanzees use a variety of tools that gives them access to food items. Mound-building termites are ‘fished’ with twigs. Hard-shelled nuts are smashed with a stone or log.

Habitat: Mature forests and colonizing forests are the most common habitats but swamp forest, savannah woodlands, miombo and grasslands are also used.

Abundance: Density is less than 1 individual/km² in most areas, with 2 to 8 individuals/km² in some areas. Density varies positively with the density of large trees bearing fleshy-fruit (most notably fig trees). With about 700 chimpanzees, Mahale Mountains National Park has the largest populations of chimpanzees in Tanzania and is of world-wide importance for the long-term conservation of this species.

51 52 Group size: Most communities contain 20 to 60 individuals but some are as large as 140 individuals. Size of parties varies with food availability, number of cycling females with sexual swellings and with social affinities of community members. Communities in the Mahale Mountains vary from 45 to 101 individuals.

Age at sexual maturity: Females average about 14 years (range 9 - 23 years). In Mahale, the median age at sexual maturity is 10 years for females and 15 years for males. First birth occurs, on average, at 13.1 years in Mahale.

Gestation: About 230 days (range 202 - 261 days).

Birth weight: About 1.7 kg (range 0.9 - 2.4 kg).

Activity pattern: Diurnal and semi-terrestrial. Chimpanzees are active Social organization: Fission-fusion social organization. Members of a 10 to 13 hours per day. They forage about 55 % of the day, mainly in chimpanzee community break up to form temporary parties. Average trees, but travel mostly on the ground. Traveling takes up about 14 % party size in the Mahale Mountains is six individuals. Females usually, of the day. Grooming (6 %) and resting (25 %) often occur on the but not always, move out of their natal communities. Average age at ground. Adults construct nests in trees for day and night resting. Males which females depart their natal community is about 11 years in often nest at lower heights than females, perhaps due to their heavier Mahale. Males form linear dominance hierarchies. High-ranking body weight. males are more aggressive than low-ranking males. To maintain their rank in a community, adult males often form strategic alliances with Distance moved per day: Average varies from 1.0 to 4.8 km/day, one or more other adult males. depending on the site. At Mahale, the average day range is 4.8 km. Grooming is an important social behaviour. Among males, grooming Males range farther than females. may be exchanged for support in agonistic interactions. All

chimpanzees are playful to a certain extent but play is most frequent Size of area used (home range): Varies from 6 to 32 km². Communities among individuals that are 2 to 4 years of age. in savanna woodlands typically have a larger home range and a lower population density than communities in moist forests. Vocalizations: Broad vocal repertoire. The most impressive

vocalization is the ‘pant-hoot’ (a loud, low booming sound that builds

53 54 up and is followed by high-pitched whoops). The ‘pant-hoot’ is given Uganda from countries where primates are frequently hunted and in situations of excitement and can be heard at a distance of > 1 km. eaten. Many chimpanzees are incidentally maimed or killed by traps During ‘pant-hoot’ displays, males often drum on a tree with their intended to capture other species. hands and feet. The ‘pant-grunt’ is given as a signal of deference when a higher-ranking individual approaches or threatens. High- Best viewing at Greystoke Mahale Camp: Greystoke Mahale Camp is pitched screaming is used against an aggressor. ‘Hoos’ are given located within the home range of M-community (about 55 individuals). when curious or in mild distress. ‘Wraah’ barks indicate alarm. The guides and trackers of Greystoke Mahale Camp will brief you on the chimpanzee viewing protocols and take you to the closest party of Predators: Leopards, lions, crocodiles and humans. Lethal aggression M-community. Occasionally, members of M-community visit of males towards neighboring groups occurs and is linked to improve Greystoke Mahale Camp. access to food and females.

Longevitymossambicensis.: About 60 years.

Other: ‘Self-medication’ frequently occurs. For example, in Mahale, chimpanzees swallow folded leaves of Aspilia These are covered with minute spines that hook and remove intestinal worms. Chimpanzees also chew the bitter pith of Vernonia amygdalina to control gut pathogens.

The most common cause of death in Mahale is disease, accounting for 48% of all deaths. At Mahale, 50 % of the infants die before they are weaned (which occurs at about 3.5 to 4.5 years of age).

Conservation status: An ‘Endangered’ species.

Conservation threats: Habitat degradation, loss and fragmentation due to agricultural and logging activities. A major threat to chimpanzees in Central Africa and West Africa is hunting for the bush meat trade. Although the consumption of primates is rare in East Africa, chimpanzees are killed while crop-raiding and, increasingly, by immigrant hunters who have moved eastward into Tanzania and

55 56 Checklist Primates of the Mahale Mountains National Park

Red-tailed Monkey □ Seen!

Southern Lesser Galago □ Yellow Baboon □

Angolan Colobus □ Monkey Silver Greater Galago □

Red Colobus Monkey □ Vervet Monkey □

Robust Chimpanzee □

Silver Monkey □

57 58 Primates of Mahale Mountains National Park, Tanzania

Thomas M. Butynski (PhD) has worked on primates and other mammals across equatorial Africa since 1970. He has developed and implemented many projects for the conservation of biodiversity, primarily in tropical forests. For many years he served as the Vice- Chair of the Africa Section of the IUCN/SSC Primate Specialist Group and as Senior Editor of the journal, African Primates. At present he is Co-Leader of the Eastern Africa Primate Diversity and Conservation Program.

Yvonne A. de Jong (MSc) has worked on primates in Southeast Asia and East Africa since 1995. Her primary research focus as a field scientist is on the diversity, ecology, distribution, taxonomy and conservation status of African primates. At present she is Co-Leader of the Eastern Africa Primate Diversity and Conservation Program.

Stephen Nash is a scientific illustrator with Conservation International. He has drawn hundreds of primates for various field guides and articles. He is based at Stony Brook University, in the State of New York, USA, where he is a Research Associate in the Department of Anatomical Sciences and an Adjunct Associate Professor in the Department of Art.

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