Allochrocebus preussi (Matschie, 1898)

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cercopithecidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 550-755 : 675-676

57.

Preuss’s 9 Monkey

Allochrocebus preussi .

French: Cercopitheque de Preuss / German: Preuss-Meerkatze / Spanish: Cercopiteco de Preuss

Other common names: Black Monkey, Preuss’s Guenon; Bioko Preuss’s Monkey (insularis), Cameroon Preuss'’s Monkey (preussi)

Taxonomy. Cercopithecus preussi Matschie, 1898 ,

Cameroon, Victoria.

Two subspecies are recognized.

Subspecies and Distribution.

A. p. preussi Matschie, 1898 — SE Nigeria and SW Cameroon highlands (Cross River Highlands, Korup National Park, Bamenda Highlands, and Mount Cameroon).

A. p. insularis Thomas, 1910 — Bioko I (Equatorial Guinea).

Descriptive notes. Head—body 42-70 cm (males) and 37-55 cm (females), tail 50-76 cm (males) and 41-67 cm (females); weight 4.7-10 kg (males) and 2.9-4.3 kg (females). Preuss’s Monkey is similar to L'Hoest’s Monkey (A. lhoesti ), but it has only a small amount of white fur on its upper chest and throat, merging upward with gray cheek whiskers. Hairs on crown and nape are black, ticked with gray. It has a saddle ofsolid chestnutred. Flanks are gray with buff banding, underside is dark gray, and limbs are entirely black. Although tail is like the back proximally, it grades into a dark gray, with its terminal one-fourth being black. Preuss’s Monkey usually holds its tail with a hook or loop at the end, often described as a question mark. Face is uniformly gray, and ears are hidden by crown hairs. Eyes appear very dark reddish-brown. Gray hairs have only two pairs of white and black bands (unlike I'Hoest’s Monkey, which has four pairs). Scrotum is light blue. Female Preuss’s Monkeysare similar to males, but slightly smaller. The “Cameroon Preuss’s Monkey” (A. p. preussi ) is the larger of the two subspecies, with a tail that is longer than head-body length. Dorsal saddle is a brighter chestnut than in the “Bioko Preuss’s Monkey” (A. p. insularis), and it extends more posteriorly. Tail is a lighter gray. The Bioko Preuss’s Monkey is smaller than the Cameroon Preuss’s Monkey, with a darker gray tail that is relatively shorter (i.e. about equal to head-body length). Dorsal saddle is less bright and does not extend as far on to the tail.

Habitat. Primary and secondary submontane and montane forest, preferring elevations of 800-2500 m. The Cameroon Preuss’s Monkey is found in highland forests of the Cameroon-Nigeria border regions. It may also occur in isolated forest patches in mountainous grasslands. On Bioko Island, the Bioko Preuss’s Monkey shows a preference for Schefflera (Araliaceae) forest above 1500 m, but it is also found in lowland forest (e.g. at 450 m in the Caldera on Bioko Island).

Food and Feeding. Although there has been little systematic study of their feeding behavior, Preuss’s Monkeys are known to eat fruits, seeds, leaves, flowers, small aquatic animals, and termites. In the study at Kilum, 52% of the diet of the Cameroon Preuss’s Monkey was fruit and seeds. As with other primates with diets of largely seasonally available foods, varied diets likely have important influences on movements and behavioral habits. The terrestrial nature of Preuss’s Monkeys probably serves them well in their high-elevation habitats, where the terrain is often broken by rocky outcrops.

Breeding. There is no specific information for this species, but Preuss’s Monkey is assumed to have similar patterns to those of the Sun-tailed Monkey (A. solatus ).

Activity patterns. Preuss’s Monkey is diurnal and largely terrestrial, spending most of its ime on the ground or in lowerlevels of the forest. The degree of terrestriality varies by study site, which may indicate a difference between the subspecies. On Bioko Island, more than 60% of observations of the Bioko Preuss’s Monkey were on the ground or in the shrub layer. In contrast, a study in Cameroon recorded the Cameroon Preuss’s Monkey spending most of its time in trees but traveling on the ground to cross open spaces.

Movements, Home range and Social organization. A number of factors contribute to the lack of information for Preuss’s Monkeys. They are rare and of a very shy and secretive nature. Moreover, they live in areas that are often difficult to reach because of physical constraints or political restrictions. Consequently, home range size is not yet known. A study in Cameroon found variation in the composition of groups on different days in the same location (at similar times of day). This suggested either a flexible grouping pattern or overlap of home ranges. Nevertheless, Preuss’s Monkeys are normally found in unimale-multifemale groups of 2-19 individuals. On occasion, more than one adult male may be seen in the group. Single males are often seen, but never single females. Unlike many other guenons, Preuss’s Monkey rarely interacts with other primates. At dusk, adult males give one loud call, which is answered by neighboring males as the groups settle down for the night. This call is apparently absent in the other species of Allochrocebus . Alarm calls take the form of chirps in females and “hacks” in males.

Status and Conservation. CITES Appendix II. Classified as Endangered on The IUCN Red Lust (as Cercopithecus preussi ), including both subspecies. Preuss’s Monkey is listed as a Class B species of the African Convention on the Conservation of Nature and Natural Resources. Populations have been severely affected by habitat destruction and bushmeat hunting. Cameroon’s forests, for example, have been severely degraded by cultivation, fire, and the collection of wood for fuel. As a result, little montane forest remains in the mainland part of its range, and this forest area is not protected. Preuss’s Monkey is highly susceptible to hunting because it is semi-terrestrial and relatively large. Hunting has led to a decline in its population across its distribution, but particularly on Bioko Island where the estimated decline exceeds 50% over a 20year period. Recent reports indicate a steady increase in the number of carcasses of Bioko Preuss’s Monkeys found in the bushmeat market of Malabo on Bioko Island. In mainland Cameroon, Preuss’s Monkey is uncommon, and its populations are highly fragmented. Surveys of its status and distribution across its entire distribution are needed. Improved protection of montane forest, increased law enforcement, and banning of bushmeat hunting are urgently required. The Cameroon Preuss’s Monkey occurs in Takamanda, Mount Cameroon, and Ebo national parks in Cameroon and the Okwangwo Division of Cross River National Park and on the still unprotected Obudu Plateau in Nigeria. The Bioko Preuss’s Monkey occurs in Basilé National Park and Southern Highlands Scientific Reserve in Equatorial Guinea.

Bibliography. Beeson et al. (1996), Cronin et al. (2010), Gautier et al. (2002), Gonzalez-Kirchner (2004), Groves (2001), Hearn et al. (2006), Kaplin (2002), Oates (2008, 2011).

Figures

On following pages: 50. Grivet Monkey (Chlorocebus aethiops); 51. Tantalus Monkey (Chlorocebus tantalus); 52. Green (Chlorocebus pygerythrus); 55. Bale Mountains Monkey (Chlorocebus djiamdjamensis); 56. L'Hoest's Monkey (Allochrocebus Monkey (Chlorocebus sabaeus); 53. Malbrouck Monkey (Chlorocebus cynosuros); 54. Vervet Monkey Ihoest): 57. Preuss's Monkey (Allochrocebus preussi); 58. Sun-tailed Monkey (Allochrocebus solatus).

Subspecies and Distribution. A. p. preussi Matschie, 1898 — SE Nigeria and SW Cameroon highlands (Cross River Highlands, Korup National Park, Bamenda Highlands, and Mount Cameroon). A. p. insularis Thomas, 1910 — Bioko I (Equatorial Guinea).