Chlorocebus pygerythrus (F. Cuvier, 1821)

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 : 673-674

54.

Vervet Monkey

Chlorocebus pygerythrus

French: Vervet bleu / German: Stdliche Grinmeerkatze / Spanish: Vervet oriental

Other common names: Black-chinned Vervet Monkey (pygerythrus), Hilgert's Vervet Monkey (hilgerti), Pemba Vervet Monkey (nesiotes), Reddish-Green Vervet Monkey (rufoviridis), Wittu Islands Vervet Monkey (excubitor)

Taxonomy. [Simia] pygerythra F. Cuvier, 1821 ,

Africa (= South Africa).

Further taxonomic work is required to assess the validity of the proposed subspecies. C. pygerythrus hybridizes with C. ae thiops in south-western Ethiopia and with C. tantalus in Uganda and in DR Congo. In northern Tanzania, some C. pygerythrus have very pale hands and feet, leading to questions about the descriptive features of this species. Dwarf forms (nesiotes and excubitor) are found on islands in the Indian Ocean and Lake Victoria. Five subspecies recognized.

Subspecies and Distribution.

C.p.pygerythrusF.Cuvier,1821—Botswana,Zimbabwe,SMozambique,Namibia,SouthAfrica(Kwazulu-NatalandTransvaalprovinces),Swaziland,andLesotho,SoftheZambeziRiver.

C.p.excubitorSchwarz,1926—NEKenya(PateandMandaIsintheLamuArhipelago).

C.p.hilgertiNeumann,1902—SEthiopia(EthiopianRiftValleyandintopartsofthehighlandsEoftheRift),SWSomalia,EUganda,Kenya,andNTanzania.

C.p.nesiotesSchwarz,1926—ETanzania(PembaandMafiaIs).

C. p. rufoviridis 1. Geoffroy Saint-Hilaire, 1843 — SW Uganda (S of Lake Victoria), Rwanda, Burundi, W Tanzania, Malawi, N Mozambique, and E Zambia (E of the Luangwa Valley) to the Zambezi River.

Descriptive notes. Head-body 42-70 cm (males) and 30-62 cm (females), tail 45-76 cm (males) and 41-66 cm (females); weight 3.1-6.4 kg (males) and 1.5-4.9 kg (females). The Vervet Monkeyis grizzled-gray or olive above. This color extends to outer surfaces of limbs (which are not gray as they are in the Tantalus Monkey, C. tantalus ) and is darker (often black) on hands, feet, and tail tip. Cheek whiskers are very short and combine with a white brow band to completely encircle the otherwise black face, with the former grading into the greenish speckled crown and neck. Fur at base oftail and in perineal region is bright red and does not form tufts , as it does in most Tantalus Monkeys. Scrotum is turquoise-blue; this color has been found to vary in some study subjects, perhaps related to stress, nutrition, or dominance status. The “Black-chinned Vervet Monkey” (C. p. pygerythrus ) is ashy-gray to olive-green above, tending to be grayer in the west and more greenish in the east. “Hilgert’s Vervet Monkey” (C. p. hilgerti) is generally a paler brownish-yellow than other subspecies, often lacking the dark feet and hands of the other subspecies. The “Wittu Islands Vervet Monkey” (C. p. excubitor) resembles Hilgert’s Vervet Monkey, but is smaller. The “Reddish-Green Vervet Monkey” (C. p. rufoviridis) is a large subspecies, with orangey-yellow or fawn upperparts and (often) a reddish-infused underside. Cheek whiskers are long and speckled. A form from the Mahale Mountains region in western Tanzania is geographically close to the Reddish-Green Vervet Monkey, but lacks the reddish or orange tint that at least some Reddish-Green Vervet Monkeys have, and phenotypically is difficult to ascribe to a subspecies. The “Pemba Vervet Monkey” (C. p. nesiotes) resembles the Reddish-Green Vervet Monkey, but is smaller.

Habitat. Savanna, open woodland, forest-grassland mosaic, forest edge, cultivated areas, and highland regions to 1800 m above sea level. Vervet Monkeys are often associated with miombo woodland. They are generally absent from desert areas and deep forest. Vervet Monkeys in game parks have adapted well to tourist activities and are pests around some lodges.

Food and Feeding. Vervet Monkeys have a diverse diet and feed on leaves, fruits, seeds, gums, flowers, and small animal prey. They raid crops and orchards and readily acclimate to humans.

Breeding. Female Vervet Monkeys reproducefor the first time at 4-6 years of age. They may reproduce yearly, but in most habitats with reduced food availability, they reproduce at a slower rate. Phytochemical contents of some ingested flower species have been implicated in influencing the reproductive cycles of Vervet Monkeys. There is no sexual swelling in the female. Gestation lasts c.6 months, followed by a single birth. The neonatal hair is dark, gradually turning to the adult coloration by six months of age. The face is pale at birth, turning darker gradually over the first few months.

Activity patterns. Vervet Monkeys are diurnal and mainly terrestrial. In general, they spend 30-40% of their time feeding and a similar amount of time scanning for predators and conspecifics. These figures are subject to variation based on season, locale, and a variety of other factors. Most importantly, the effect of group size on activity patterns provides clear evidence that Vervet Monkeys derive benefits from living in larger groups.

Movements, Home range and Social organization. Vervet Monkeys live in multimale— multifemale groups of up to 75 individuals. Many unrelated males can be present in a group at any given time. Males transfer among groups, whereas females remain in their natal group (philopatric) and maintain fairly strict matrilineal relationships. This provides ample opportunity for allomaternal care and complex relationships among siblings—social behaviors that are also seen in other species of Chlorocebus . Often aggressively territorial, Vervet Monkeys have been observed to shift their home ranges away from other groups. On other occasions, they have moved home ranges in response to habitat deterioration. Such shifts have been observed to result in group fusion in some cases. The home rangesize is ¢.23 ha, but varies by location and habitat type. Although considered a “savanna species,” their home ranges are typically restricted to areas with an ample number of trees. The vocal repertoire of Vervet Monkeys has been well studied. It includes a variety of predator-specific alarm calls that are used to communicate danger to conspecifics. Vervet Monkeys are favored prey of Leopards (Panthera pardus) in some regions. Pythons and martial eagles (Polemaetus bellicosus) also prey on them to a lesser extent.

Status and Conservation. CITES Appendix II. Classified as Least Concern on The IUCN Red List. The subspecies have not been assessed. The Vervet Monkeyis listed as Class B in the African Convention on the Conservation of Nature and Natural Resources. It is widely distributed and often common; however,it is very patchily distributed, probably because of its need to drink water daily. There are no major threats. Vervet Monkeys are considered vermin in parts of their distribution, and they are actively persecuted (shot and hunted) by landowners in areas where they raid crops or interact with humans. They are also hunted for their meat in some areas (e.g. the Turkana district of Kenya). Vervet Monkeys occur in most protected areas in their range. The Black-chinned Vervet Monkey occurs in at least eleven protected areas: Maputo Game Reserve in Mozambique; Addo Elephant, Kruger, Mountain Zebra, Richtersveld, and Tsitsikamma national parks, Burman Bush and Oribi Gorge nature reserves, and Ndumu and Hluhluwe-Umfolozi game reserves in South Africa; and Zimbabwe National Park in Zimbabwe. Hilgert’s Vervet Monkey occurs in Samburu and Amboseli national parks in Kenya and Lake Manyara and Serengeti national parks in Tanzania. The Pemba Vervet Monkey occurs in Ngezi Forest Reserve in Tanzania. The Reddish-Green Vervet Monkey occurs in Gombe Stream, Mahale Mountains, Mikumi, Ruaha, and Udzungwa Mountains national parks in Tanzania and Lower Zambezi National Park in Zambia. The Wittu Islands Vervet Monkey is not found in any protected areas. A lack of updated records that take into account this most recent classification of subspecies of Vervet Monkeys suggests that this list may need careful reassessment.

Bibliography. Butynski & de Jong (2011), Cheney et al. (1988), Gerald et al. (2010), Groves (2001), Henzi (1985), Henzi & Lucas (1980), Isbell (1990, 1995), Isbell & Young (1993), Isbell, Cheney & Seyfarth (1990, 1991), Isbell, Young et al. (2009), Kingdon, Gippoliti, Butynski & de Jong (2008), Lee (1984, 1987), Struhsaker (1967a, 1967b, 1973, 1976), Turner et al. (1997), Whitten (1983, 1988).

Figures

49. Patas Monkey (Erythrocebus patas), 50. Grivet Monkey (Chlorocebus aethiops), 51. Tantalus Monkey (Chlorocebus tantalus), 52. Green Monkey (Chlorocebus sabaeus), 53. Malbrouck Monkey (Chlorocebus cynosuros), 54. Vervet Monkey (Chlorocebus pygerythrus), 55. Bale Mountains Monkey (Chlorocebus djamdjamensis), 56. L’Hoest’s Monkey (Allochrocebus lhoesti), 57. Preuss’s 9 Monkey Allochrocebus (null), 58. Sun-tailed Monkey (Allochrocebus solatus)

Subspecies and Distribution. C.p.pygerythrusF.Cuvier,1821—Botswana,Zimbabwe,SMozambique,Namibia,SouthAfrica(Kwazulu-NatalandTransvaalprovinces),Swaziland,andLesotho,SoftheZambeziRiver. C.p.excubitorSchwarz,1926—NEKenya(PateandMandaIsintheLamuArhipelago). C.p.hilgertiNeumann,1902—SEthiopia(EthiopianRiftValleyandintopartsofthehighlandsEoftheRift),SWSomalia,EUganda,Kenya,andNTanzania. C.p.nesiotesSchwarz,1926—ETanzania(PembaandMafiaIs). C. p. rufoviridis 1. Geoffroy Saint-Hilaire, 1843 — SW Uganda (S of Lake Victoria), Rwanda, Burundi, W Tanzania, Malawi, N Mozambique, and E Zambia (E of the Luangwa Valley) to the Zambezi River.