The recent IUCN report, Primates in Peril (2014-2016) lists the 25 most endangered primates. The list is provided below, with details on each species and their current plight.
Rondo dwarf galago, Tanzania
While searching for information on the rondo dwarf galago (Galago rondoensis), I came across the Dwarf Galago Project. The photo below is attributed to this project:
The Rondo Dwarf Galago, also called Rondo bushbaby, is tiny, adults weighing around 60 grams on average. These galagos can be found in only two areas of Tanzania. They are nocturnal and feed on insects and fruit, while they spend their days in nests in the tree canopy. Predators include owls, genets, civits and snakes.
The dwarf galago is greatly threatened due to loss of habitat from logging (deforestation).
Roloway monkey, Côte d’Ivoire, Ghana
Roloway Monkey at La Vallee de Singes at Romane (Vienne, Poitou-Charentes), France – Hans Hillewaert (Creative Commons attribution – share alike 3.0)
The Roloway monkey or Roloway guenon (Cercopithecus roloway) is found in the eastern Cote d’Ivoire and western Ghana – especially the Ankasa Resource Reserve, near the Ivory Coast. It is markedly characterized by a rather long, white, goat-like beard. Adult body size is from 40 to 55 centimetres, weight 4 to 7 kilograms. Social groups of 15 to 30 individuals are aboreal and feed on flowers, fruits, seeds and insects.
Deforestation and bushmeat hunting threaten this primate. See also: www.iws.org/species_roloway.html
Bioko red colobus, Equatorial Guinea (Bioko Is.)
The Bioko red colobus (Procolobus pennantii pennantii) is found mainly in the southwest corner of Bioko Island, Central West Africa. This extremely vocal, arboreal primate lives in large groups in rainforest and marsh forest areas – groups are multi-male and multi-female, with young. Diet comprises foliage, flowers, fruits and seeds, which are mainly eaten in the morning and in the evening. Upper parts are black or brownish. Arms, legs and head are a reddish or chestnut brown. There is no distinct thumb. Head and body length is about 53 to 63 centimetres, tail 60 to 70 centimetres, and weight is 7 to 11 kilograms.
The decline of the Bioko red colobus has been due to loss of habitat and extensive bushmeat hunting. See also: www.arkive.org/pennants-red-colobus/procolobus-pennantii
Tana River red colobus, Kenya
Found in southeastern Kenya, in a narrow corridor – gallery forest – near the Tana River, the Tana River red colobus or eastern red colobus (Procolobus rufomitratus) feeds mainly on leaves. Occasionally this diet is supplemented with unripe fruit, seeds and moss. At times soil, clay and charcoal are consumed to aid digestion of toxic leaves. Because of the poor nutritional quality of this food, this primate spends much of its time foraging. Large groups, often with more females than males, tend to be standard. The Tana River red colobus has a dark greyish face, lighter greyish-brown body fur and a reddish-brown crown.
A forest dependent primate, the numbers of Tana River red colobus have decreased due to major loss of habitat. See also: http://www.primate-sg.org/storage/PDF/Tana%20River%20Red%20Colobus.pdf
Grauer’s gorilla, DRC
Also known as the eastern lowland gorilla, Grauer’s gorilla (Gorilla beringei graueri) inhabits mountainous forests – often at lower elevations – of eastern Democratic Republic of the Congo. This gorilla is the largest of four gorilla subspecies and the largest of the primates. The characteristic jet black coat turns silver at the back as the male of the species ages (similar to other gorillas). Males average 163 kg or 360 pounds, although they can grow to over 500 pounds. Females are usually about half that weight. Males stand to about 1.76 metres or about 5 ft. 9 inches, females 1.60 metres or 5 ft. 3 in. or less. Due to their large size, gorillas eat often – large groups of up to 30 individuals may forage together for foliage, fruit, seeds, stems and bark, and occasional insects such as ants and termites.
This sociable, peaceful primate is threatened in general by habitat loss, and by civil unrest, mining activities, and bushmeat hunters. Violence in the area often prohibits research. See also: http://www.wcs.org/saving-wildlife/great-apes.aspx
Madame Berthe’s mouse lemur, Madagascar
The nocturnal Madame Berthe’s mouse lemur (Microcebus berthae), smallest of the mouse lemurs and smallest primate, attains a body length of about 92 millimetres (3.6 in.) and a seasonal weight of about 30 grams (1.1 oz.). It is found in dry, deciduous forest of western Madagasgar, especially in the Kirindy Mitea National Park. A solitary forager, diet includes sugary insect secretions, flowers, fruit, gum, arthropods and small vertebrates such as geckos and chameleons. Mainly solitary when sleeping, the mouse lemur does interact with others of its species.
Madame Berthe’s mouse lemur is seriously affected by deforestation and predators. See also: www.arkive.org/madame-berthes-mouse-lemur/microcebus
Sclater’s black lemur, Madagascar
This lemur (Eulemur flavifrons) has distinctive blue eyes. Otherwise, male and female look markedly different – the male has a black coat, the female is blonde or reddish-brown with paler brown underparts. Restricted to an area of northwestern Madagascar, this animal inhabits subtropical moist and dry forest – it lives in pairs (the female chooses its mate) or in groups of up to about 10 individuals. Head and body length are about 39 to 45 centimetres, tail is 51 to 65 centimetres and weight is 2 to 2.5 kilograms. Diet includes leaves, fruit, flowers, bark, and at times, insects.
Serious threats to this primate are deforestation and hunting – for the pet trade and for fur and meat. See also: www.madagascar-wildlife.com/mammals/sclaters-lemur/
Red ruffed lemur, Madagascar
Madagascar’s red ruffed lemur (Varecia rubra) is found in the rainforest of the eastern Masoala Peninsula. It is one of the island’s largest primates, with a body length of about 53 centimetres, a tail of 60 centimetres and a weight of 3.3 – 3.6 kilograms. This lemur has a reddish coat, black face, feet and tail, and a cream- or buff-colored spot at the nape of the neck. Diurnal – most active in the morning and the evening – it feeds mainly on fruit (especially figs), nectar and pollen, supplimented with leaves, shoots and seeds. Matriarchal groups of as many as 16 individuals may forage together. (Larger groups have been recorded.) The raucous, booming call of the red ruffed lemur may be heard for miles.
Because of habitat loss due to logging and mining, as well as capture for the illegal pet trade and hunting for meat and fur, this lemur is threatened – though animals outside the Masoala National Park may be more severely endangered. See also: www.bristolzoo.org.uk/red-ruffed-lemur
Northern sportive lemur, Madagascar
This lemur’s habit of taking a boxer-like stance when threatened, has led to its name. Lepilemur septentrionalis is also known as the sahafary sportive lemur or the northern weasel lemur. It can only be found in deciduous forest at the extreme northern tip of Madagascar. Coat is grey-brown, head and body length is about 28 centimetres and tail about 25 centimetres, weight about 700 to 800 grams. This arboreal, nocturnal lemur has binocular vision. Because its diet consists mainly of leaves, it is a cecotroph – that is, it must redigest its feces in order to ferment the leaves in its gut to allow bacteria to break down the cellulose in the leaves. In this way it is able to extract as much nutrition as possible. Though it is folivorous, this lemur does suppliment with some fruits and flowers. The males tend to be solitary except when mating, so a “group” consists of a mother and her offspring (she gives birth to one baby at a time). The extremely territorial males aggressively defend their territory. Their call is loud and crow-like.
Possibly one of the rarest, most endangered lemurs, the northern sportive lemur is severely threatened due to habitat loss and being hunted for food – it is also a favorite food of the local boas. See also: www.arkive.org/northern-sportive-lemur/lepilemur-septentrionalis/
Silky sifaka, Madagascar
A striking sifaka (Propithecus candidus) with long, white, silky-textured hair that contrasts sharply with a black face and deep orange eyes, is also known locally as the silky simpona. The name refers to the hiss-like, “shee-faak” alarm call. Restricted to the rainforest of northeastern Madagascar, it is one of nine sifaka species. A large lemur, total body length is about 93 to 105 centimetres, weight 5 to 6.5 kilograms (11-14 lbs.). Diurnal, groups of 2 to 9 individuals may feed, rest, play, groom and travel together. Diet is mainly leaves and seeds from a variety of plants, but supplimentary fruit, flowers, bark, and even soil, may be eaten. Sifakas tend to take care of infants communally.
Due to the illegal logging of precious hardwoods and the use of wood for fuel, the silky sifaka suffers loss of habitat. The animal is also hunted extensively for food. See also: www.simpona.org
One of the largest lemurs, the Indri (Indri indri) is found in rainforest on the eastern side of Madagascar. The Malagasy name is “babakoto”, which relates to mythology and translates as “father of a little boy”. Head and body length is between 64 and 72 centimetres, tail 4 to 5 centimetres and weight is about 6 to 9.5 kilograms. This is the only lemur with a vestigial tail – the coat is silky black and white. Diurnal tree-dwellers, indris may forage for food over long distances, diet composed chiefly of a variety of leaves, although fruits, flowers, seeds and, less often, soil are consumed. Family groups of two adults with young are common, although in some areas larger groups may be found. Monogamous, an indri will only find a new partner after a mate’s death. Characteristic howling calls unite individuals.
Though the indri has been considered sacred and figures in Malagasy myths, a deterioration of traditional beliefs has led to habitat loss and a decrease in numbers due to hunting. See also: www.arkive.org/indri/indri-indri/
Pygmy tarsier, Indonesia (Sulawesi)
A nocturnal and mainly arboreal primate, the pygmy tarsier (Tarsius pumilus) is found in mossy forest of central Sulawesi. Long considered extinct in the wild, in 2008 a research team from Texas A&M University discovered two males and two females (one escaped) in the Lore Lindu National Park. The head/body length of this primate is approximately 85 to 110 mm (about 4 inches) and its hairy tail is about 135 to 275 mm long. Its large eyes are about 16mm in diameter – it has a wide field of vision and the ability to rotate its head almost 360 degrees. This tarsier has nails on all five hand digits and on two digits of each foot. Not much is known about the social relationships and breeding of this tarsier, though based on data on other tarsiers it is thought monogamous pairs may remain together for about fifteen months and they may have two breeding seasons per year. Diet is wholly carnivorous – insectivorous. Deforestation could be a threat, but the pygmy tarsier lives in a remote area where human habitation is sparse – data is insufficient. See also: http://animaldiversity-ummz.umich.edu/accounts/Tarsius_pumilus/
Javan slow loris, Indonesia (Java)
Found only in western and central Java, the Javan slow loris (Nycticebus javanicus) is nocturnal and arboreal. It ranges through secondary forests and forests of bamboo and mangroves, moving slowly – rather than jumping – from tree to tree. Fur is brown to reddish brown – a distinctive white diamond shape marks the forehead, extending onto the snout. Head and body length is about 29 centimetres, weight is less than 2 kilograms. Though usually found alone or in pairs, small groups have occasionally been noted. The Javan slow loris usually gives birth to one offspring. Diet consists of fruit, tree sap, insects, bird eggs and at times lizards and small mammals. This primate is unique since it has a venomous bite.
Poaching for the exotic pet trade and use in medical research, as well as habitat loss are major threats. Existing wildlife laws are not strictly enforced. Those animals taken as pets often have their front teeth clipped or removed to avoid a possible toxic bite. This practice is cruel and often leads to infection, malnutrition and death. See: www.internationalanimalrescue.org/projects/25/saving+the+slow+loris.html
Pig-tailed langur, Indonesia (Mentawai Is.)
Also called the pig-tailed snub-nosed monkey (Nasalis or Simias concolor), the pig-tailed langur is found off the west coast of Sumatra, in the primary forests in the interior of the Mentawai Islands. It is diurnal and semi-terrestrial. Males and females may be a light buff or a dark grey color – both have a black face. The tail is rather short and hairless. An adult male averages 8 kilograms and a female, 7 kilograms. An adult male and one or more females with young comprise a breeding group. A female gives birth to one offspring and only between June and July. Diet includes leaves, fruits and berries. Small groups of up to about 8 individuals may feed together in the morning and in the late afternoon. Loud nasal barks followed by gasps distinguishes this primate.
Major threats are deforestation because of logging and human predation for food. See more on: http://www.iucnredlist.org/details/20229/0
Delacour’s langur, Vietnam
This langur (Trachypithecus delacouri) is found in tropical forests of north-central Vietnam, living among limestone cliffs, where it often sleeps in caves. It is diurnal and predominantly terrestrial. Mainly black fur is marked with distinctive creamy-white fur on rump and outer thighs and some white on the facial cheeks – a crest of long hair stands upright over forehead and crown. An adult male is about 57 to 62 centimetres in head/body length and weighs approximately 7.5 to 10.5 kilograms – an adult female is generally slightly smaller overall. The Delacour’s langur is often found in small groups with one male and a number of females with offspring – females give birth to one offspring at a time. Diet consists primarily of leaves, but may also be supplimented with shoots, fruit, flowers, seeds and bark.
Loss of habitat and being hunted for traditional medicine are major threats to this primate. More recently the development of the tourist trade appears to be another possible danger. See also: www.arkive.org/delacours-langur/trachypithecus-delacouri/image-G17005.html
Golden-headed or Cat Ba langur, Vietnam
A handsome primate, the Cat Ba langur (Trachypithecus poliocephalus) – formerly known as the golden-headed langur – is marked with golden to yellowish-white fur from head and neck to shoulders. The face is black – much of the body is dark brown, with a band of grey fur on thighs to back. The tail (about 85 centimetres long) is longer than the head and body (about 50 centimetres). This diurnal primate is only found on Cat Ba Island, where it inhabits limestone cliffs, sleeping – well sheltered – in caves. Groups usually consist of one male with a number of females and their young. Much of each day is spent foraging and then resting. Diet is primarily leaves, though some fruits, flowers, shoots and bark are also eaten.
Approximately 65 Cat Ba langurs may survive in the wild. In the past these animals were hunted for traditional medicine – “monkey balm”. Now, because the remaining langurs live in fragmented groups, and because of low reproductive output (females give birth to a single baby every two to three years), numbers may decline rapidly. See also: http://www.catbalangur.org/Langur.htm
Western purple-faced langur, Sri Lanka
The western purple-faced langur, or purple-faced leaf monkey (Trachypithecus or Semnopithecus vetulus nestor), found in Sri Lanka, is seen in a variety of habitats such as tropical rainforest, monsoon scrub and dry evergreen forest – often near a good source of water. But if the natural habitat is disturbed, this primate can also be found in semi-urban areas and other areas with good canopy cover. And if trees are lacking, it can even be found on the ground. Body and limbs are usually brownish-black, face is actually greyish-black with rather bushy facial whiskers coloured from white to pale brown. The tail is long and the thumb is much reduced. Head and body length of an adult male is about 50 to 65 centimetres, tail is about 67 to 85 centimetres long and weight is about 3.4 to 9.4 kilograms. Females are slightly smaller. Groups usually include one male (possibly two), one to seven adult females and various subadults, juveniles and infants. Females give birth to one baby at a time. Diet is mainly leaves, but supplemented with fruit, flowers and seeds.
Threats to this primate include deforestation, poisoning to prevent raiding of crops and hunting for traditional medicine and food. See also: http://www.arkive.org/purple-faced-langur/trachypithecus-vetulus/image-G16590.html
Grey-shanked douc monkey, Vietnam
Apparently restricted to the central highlands of Vietnam – to primary and disturbed semi-evergreen and evergreen rainforests, the grey-shanked douc monkey or langur (Pygathrix cinerea) is very distinctive. Face is yellow-orange to light brown with a white mouth, white whiskers tinged with red-orange fur. The body is a light grey, with dark grey legs and a long white tail (almost body length) ending in a tassel. Males, at about 10.9 kilograms, are slightly larger than females. This primate is usually found in very social groups of four to fifteen individuals who play and groom together and jointly care for infants. The females give birth to one offspring at a time. Diurnal, the monkey sleeps and feeds in treetops. Diet is mainly young, tender leaves, but also fruits, flowers, buds and seeds.
The population in Vietnam is fragmented due to habitat loss and being hunted for bush meat and for traditional medicine (“monkey bone balm”) and for the exotic pet trade – infants are especially prized. The Vietnam War greatly impacted the population, since these primates were used for target practice! See also: www.arkive.org/grey-shanked-douc/pygathrix-cinerea
Tonkin snub-nosed monkey, Vietnam
A distinctive primate, the Tonkin, snub-nosed monkey (Rhinopithecus avunculus) was thought extinct until a small population was found in North Vietnam. The cream-coloured, flattened face and upturned nose and a cream-coloured chest contrast sharply with a black/brownish back and outer limbs. The long tail – 66 to 92 centimetres – looks greyish. Head and body length are about 51 to 65 centimetres and the weight of an adult male is 13.8 to 14 kilograms – females weigh a bit less. Arboreal and diurnal, and found in tropical evergreen forest, this primate eats various leaves, as well as flowers, fruits and seeds.
Fragmentation of habitat and hunting – poaching – for the illegal wildlife trade has decimated numbers. See also: http://www.arkive.org/tonkin-snub-nosedmonkey/rhinopithecus-avunculus/image-G75495.html
Cao-Vit or Eastern black-crested gibbon, Vietnam, China
Also known as the Cao-Vit black-crested gibbon, the Eastern black-crested gibbon (Nomascus nasutus) was thought to be extinct until a small population was found in northeastern Vietnam in 2002 – the range of this primate is northeastern Vietnam to an adjacent area in China. Habitat is mainly limestone forest. Overall black fur distinguishes this gibbon. Diet consists mainly of fruit, although leaves and animal matter may also be eaten.
Major loss of habitat and poaching are primary threats. See also: www.primate-sg.org/storage/PDF/Eastern%20Black%20Crested%20Gibbon.pdf
Variegated spider monkey, Colombia, Venezuela
Found in northern Columbia and northwestern Venezuela, the variegated spider monkey, or brown spider monkey (Ateles hybridus) is unique among spider monkeys for it often has blue eyes. Colour of back and limbs ranges from light to dark brown, with lighter chest and belly and a white mark on the forehead. This primate has long, spindly limbs and a long prehensile tail with a hairless pad on the end for gripping branches. Height is about 50 centimetres – the tail can be up to 75 centimetres long. Weight is 7.5 to 9 kilograms. Groups usually consist of very social multiple males and females. Females give birth to one offspring at a time. Diet is mainly ripe fruit, supplemented with leaves, flowers and seeds.
Probably the major threat to this primate is habitat loss – approximately 98% of the habitat is gone and this is an ongoing problem. Variegated spider monkeys are also hunted for food and for the wild animal trade. See also: http://www.twycrosszoo.org/brown-spider-monkey.aspx
Ecuadorian brown-headed spider monkey, Ecuador
Found in northwest Ecuador, in tropical and subtropical humid forests, the Ecuadorian brown-headed spider monkey (Ateles fusciceps fusciceps) is a large spider monkey with a prehensile tail. The adult male and adult female have a black or dark brown body, and a brown head. Head and body length is 39.3 to 58.3 centimetres, tail is 71.0 to 85.5 centimetres in length, an adult male weight is about 8.8 kilograms and an adult female weighs about 8.89 kilograms. Groups are composed of numerous males and females with young. Mainly arboreal and diurnal, diet includes primarily ripe fruit, supplemented with leaves, flowers, seeds, bark, honey, and at times, insects.
Habitat loss, impacted by copper mining, is a serious threat. See also: http://www.ptes.org/files/405_ecuador_brown-headed_spider_monkey.pdf
Ka’apor capuchin monkey, Brazil
The Ka’apor capuchin monkey (Cebus kaapori) is found mainly in the northeastern state of Maranhao, Brazil, in lowland Amazonian high forest. Body – back and outer limbs – are reddish brown, the face is whitish to a flesh-like colour, head has a black crown. hands and feet are blackish – it has a prehensile tail. This active, mischievous primate is arboreal and diurnal, living in groups of about several dozen individuals, with numerous adult males and females and young. The average weight is about 2 to 3 kilograms. Diet consists largely of fruit, although nuts – especially palm fruit nuts – flowers and insects are also eaten.
Deforestation is a major threat. See also: http://www.animalinfo.org/species/primate/cebukaap.htm#status
San Martín titi monkey, Peru
The San Martin titi monkey or Rio Mayo titi monkey (Callicebus oenanthe) is found in the upper Rio Mayo Valley of north-central Peru and areas to the south. Arboreal and diurnal, this primate inhabits some dense forest, bamboo stands, vine thickets and areas dense with palms, often near water. Distinguished by thick, light brown fur on back, reddish-orange chest and belly, whitish face with black fur around eyes and mouth, this monkey has a compact body and non-prehensile tail. The head and body length of an adult male is 30 to 30.6 centimetres, a female is 31.3 to 38.5 centimetres long and the tail is 36.9 to 40 centimetres in length. Weight is about 1.2 kilograms. Small family groups include a well bonded male and female and their young – individuals are very social and affectionate. Diet consists of a large quantity of insects, as well as fruit, leaves, flowers and seeds.
The major threat to this primate is deforestation – approximately 80% of its habitat has been destroyed. See also: www.captiveanimals.org/news/2013/08/conservationists
Northern brown howler monkey, Brazil
Tropical forests in southeastern Brazil are home to the northern brown howler monkey (Alouatta guariba guariba) – it may be found only north of the Jequitinhonha River. Arboreal and vegetarian, this primate has a stocky body with thick brown fur that may vary to a dark red or black colour. The face is dark greyish to blackish and the tail is long and prehensile. Males are larger than females – an adult male is 54 to 59 centimetres in head/body length, while the female is 45 to 49 centimetres. An adult male has a tail length of 52 to 67 centimetres and weighs from 5.3 to 7.15 kilograms and an adult female has a tail 48 to 57 centimetres in length and weighs in at 4.1 to 5.0 kilograms. Social groups are usually composed of 15 to 20 individuals. The loud howls of this primate can be heard over a kilometer away. Diet includes leaves, flowers and fruit, according to the season.
Decline in numbers may be due largely to loss of habitat. See also: www.arkive.org/brown-howling-monkey/alouatta-guariba