Cercopithecus ascanius (Audebert, 1799)

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 : 690-691

76.

Red-tailed Monkey

Cercopithecus ascanius

French: Cercopitheque ascagne / German: Rotschwanzmeerkatze / Spanish: Cercopiteco de cola roja

Other common names: Red-tailed Guenon; Black-cheeked Red-tailed Monkey (ascanius), Black-nosed Red-tailed Monkey (atrinasus), Katanga Red-tailed Monkey (katangae), Schmidt's Red-tailed Monkey (schmidti), Yellow-nosed Red-tailed Monkey (whitesidei)

Taxonomy. Simia ascanius Audebert, 1799 ,

no type locality specified. Restricted by A.B. Machado in 1969 to north-west Angola, by the lower Congo River.

C. ascanius was previously associated with C. petaurista , C. erythrogaster , and C. nictitans , all spot-nosed monkeys. It is now agreed that the cephus species group should include all lesser spot-nosed monkeys. Genetic studies suggest a relatively recent divergence from other cephus monkeys. This polytypic species requires further investigation to assess the taxonomic distinctiveness of the geographic types. P. Grubb and colleagues, in their 2003 review, raised doubts about the subspecific status of atrinasus, suggesting that more research was necessary to confirm its taxonomic validity. C. P. Groves in his 2001 Primate Taxonomy recognized five subspecies but considered the possibility of raising schmidti to a full species because it lacks the temporal whorl found in the other subspecies. C. ascanus is reported to hybridize with C. mitis stuhlmanni, C. doggetti , and C. denti . There is a transitional zone of C. a. ascanius x C. a. atrinasus where their distributions meet in north-central Angola. Intermediates of C. a. whitesidei and C. a. katangae occur between the Lualaba and Lomami rivers. C. a. atrinasus x C. a. katangae hybrids are reported from northern Angola. Five subspecies recognized.

Subspecies and Distribution.

C.a.ascaniusAudebert,1799—SWDRCongo(SoftheCongoandKasairivers)andNAngola(Sboundaries¢.8°SandElimitatc.15°E);furtherEisanapparenthybridzonewiththesubspeciesatrinasusbuttheboundariesareuncertain.

C.a.atrinasusMachado,1965—NEAngola,knownonlyfromasmallareaaroundthetypelocalityintheNWcorneroftheLundaDistrict,aroundtheWambaRiver;ithasbeenmappedfromc.8°-9°§,c.18°-18°30’E.

C.a.katangaeL.onnberg,1919—SDRCongo(mainlybetweentheKasaiandLualabarivers),NWZambia,andNAngola(to11°S,17°E,exceptforthesmallsubspeciesatrinasusenclave).

C.a.schmidtiMatschie,1892—DRCongo(EoftheLualabaRiver)extendingintoUganda,Rwanda,WBurundi,SWKenya,andWTanzania;NoftheCongoRiver,itextendsNandWoftheUbangiRiverintotheCentralAfricanRepublicandSSouthSudan.

C. a. whiteside: Thomas, 1909 — DR Congo, between the Congo and the Kasai-Sankuru rivers. Its border with the subspecies katangaeis a little south of the Sankuru, with intermediates occurring between the Lualaba and Lomami rivers.

Descriptive notes. Head-body 43-51-56 cm (males) and 34-48.5 cm (females), tail 60-92 cm (males) and 54-79 cm (females); weight 3-6 kg (males) and 1.8-4 kg (females). Dorsal coat of the Red-tailed Monkey is agouti-brown, with light (white, cream, or gray) on underside and inner side of limbs. Hair bases on body are gray, with two to four alternating red/black bands, the first pair separated from the light base by an indistinct black band; subterminal black band is longer than the rest. At least part of tail is red, with a black tip. Hands and feet are dark. There is a conspicuous heart-shaped nose spot that is white, yellow, red, or black, depending upon the subspecies. In most subspecies, there is a whorl in front of ears, from which white cheek whiskers radiate in a spiral-like pattern, almost vertical in front, and sweeping down and back below. Whiskers are bordered inferiorly by a black band, curving up medially alongside the nose spot. Circumocular bare skin is slate blue or black. There is also a blackjaw band. In the “Black-cheeked Red-tailed Monkey” (C. a. ascanius ), nose spot and temporal whorls are white. Ear tufts are bright orange-red, and cheeks are black, with black frontal and temporal bands being notably wide. Periocular skin is light blue. Its underside is gray, extending under base oftail. Tail tip is darker. Hairs are gray at their bases, with four pairs of alternating red and black bands. The “Black-nosed Red-tailed Monkey” (C. a. atrinasus) is similar to the Black-cheeked Red-tailed Monkey, but it has a black nose spot, blue circumocular rings, and black maxilla. White hairs emerging from its cheek whorl are short. Its cheek whiskers are white above, black in the middle due to lateral extension of the black maxillary zone, and gray below, extending to its throat. The “Yellow-nosed Red-tailed Monkey” (C. a. whitesidei) has a creamy yellow to deep orange nose spot and reddish ear tufts. Its black frontal band is narrow, with a reduced inferior lateral black band. Its whitish underside extends to underside of tail. Dorsal surface of tail is dark, with the distal one-third red. Its cheek whiskers do not have as much of a lateral flare as those of Black-cheeked and Black-nosed red-tailed monkeys. Whiskers are white superiorly, agouti-brown inferiorly, and gray at the throat. Periocular skin is almost black. In the “Katanga Red-tailed Monkey” (C. a. katangae), nose spot and temporal whorls are white, and skin around eyes is violet purple. Its black frontal band is narrow, and its black temporal band is reduced. Cheeks have a reduced black area, and ear tufts are reddish. Tail is very dark above with a blackish, rather than red, distal portion. Hairs differ from other subspecies in that they are white and not gray at the base with the same alternating bands of red and black. “Schmidt's Red-tailed Monkey” (C. a. schmidti) has a distinctly different face from other subspecies. Skin around eyes is a dark blue to nearly black. Nose spot and ear tufts are white. Frontal band and inferior lateral black bands are narrow. Cheeks have an extensive whitish area that extends back to partially cover ears, margined with black below. A temporal whorl is distinctly lacking in this subspecies. Its appearance is so distinctive that is has prompted debate regarding the possibility of considering it a full species. There are even reports of individuals in the southern part ofits distribution in DR Congo that have dark gray legs, sometimes extending to the back.

Habitat. A wide range of lowland, submontane, and montane forests, both dry and moist, including tropical forest, swamp forest, riparian and gallery forest, deciduous forest, forest mosaics, and Acacia (Fabaceae) woodland. Red-tailed monkeys occur in primary and disturbed secondary growth forests. The more lowland, gallery rainforest habitats are preferred by Black-cheeked Red-tailed Monkeys. Higher elevations and dry forests are inhabited by Schmidt's Red-tailed Monkey. They are reported in Brachystegia (Fabaceae) and undifferentiated woodland and on cultivated subsistence farmland and tree plantations. They are usually found near rivers and range from zero to 2500 m above sea level. Black-cheeked Red-tailed Monkeys occur at average elevations of 800 m, and Schmidt’s Red-tailed Monkey at 400-2500 m.

Food and Feeding. Diets of Red-tailed Monkeys contain at least 60% fruit, along with seeds, young and mature leaves, flowers, nectar, and sometimes bark and gum. Insects can make up 30% of the diet. Other animal matter consumed includes birds and small reptiles. They hunt African green-pigeons (7reron calva) in the Kalinzu Forest in Uganda. They have been reported to raid banana, mango, guava, and maize crops near Kibale Forest National Park, Uganda.

Breeding. Female Red-tailed Monkeys have a menstrual cycle of ¢.30 days. The gestation period is 5-6 months, and singletons are the norm. Mating generally occurs throughout the year, with some seasonality apparent in some regions correlated with rainfall and food availability. Exclusive maternal care and allomothering are practiced. Infanticide has been reported. Females reach sexual maturity at c.4 years of age and males at six years. Males emigrate from natal groups. The life span is c. 28 years.

Activity patterns. Red-tailed Monkeys are diurnal and arboreal. They spend 60-90% of their time at heights of 5-20 m above the ground, using an average forest height of c.12 m. Locomotion is quadrupedal, with climbing and leaping.

Movements, Home range and Social organization. Red-tailed Monkeys live in hierarchical, male-dominant, unimale-multifemale social groups. Average group size is 30-35 individuals. A study carried out at Ngogo in Kibale Forest National Park, Uganda, reported the maximum supportable group size of Schmidt's Red-tailed Monkey to be c.50 individuals, roughly 50% larger than the average group size of the species. This study reported two occasions, and a possible third, of group fission when a group reached 50 individuals. Studies of Schmidt's Red-tailed Monkey reported daily movements of 1400-1900 m. Home ranges are 15-68 ha.

Status and Conservation. CITES Appendix II. Classified as Least Concern on The [UCN Red List, including the subspecies schmidti. The subspecies atrinasus is classified as Data Deficient, and katangae, whitesidei, and the nominate subspecies ascanius have not been assessed. The Red-tailed Monkeyis listed as Class B in the African Convention on the Conservation of Nature and Natural Resources. Because of its occurrence in a wide variety of forest habitats, it has no major threats. Two subspecies have been evaluated. Schmidt's Red-tailed Monkey has a wide distribution in a variety of habitats, and although it is locally threatened by hunting and habitat loss and degradation, there are apparently are no threats great enough to result in a range-wide decline that would warrant listing in a threatened category. The Black-nosed Red-tailed Monkey is known only from data collected on nine individuals from the north-west Lunda District of north-eastern Angola. The remaining three subspecies have not been assessed. In general, threats to Red-tailed Monkeys include habitat encroachment from agriculture and forest exploitation. They are locally threatened by habitat loss and hunting, but they are probably able to tolerate a degree of hunting. They are hunted for food and fur (its tail fur was formerly used to cover bows). It is often killed as a crop pest, and it is used in biomedical research. Red-tailed Monkeys occur in at least 15 protected areas, including Kahuzi-Biéga and Salonga national parks, Tayna Gorilla Reserve, and Okapi Wildlife Reserve in DR Congo; Nyungwe Forest and Volcanoes national parks in Rwanda; Gombe Stream and Mahale Mountains national parks in Tanzania; Bwindi Impenetrable, Kibale Forest, and Ruwenzori national parks and Budongo, Itwara and Mabira forest reserves in Uganda; and Kakamega Nature Reserve in Kenya.

Bibliography. Butynski (1988, 2002b), Cords (1984, 1986, 1987), Cords & Sarmiento (2013), Detwiler et al. (2005), Galat-Luong (1975), Gathua (2000), Gebo & Chapman (1995), Groves (2001), Grubb et al. (2003), Haddow (1952), Hakeem et al. (1996), Jones & Bush (1988), Lambert (2000, 2002), Machado (1965, 1969), Marler (1973), McGraw (1994), Naughton-Treves et al. (1998), Sarmiento et al. (2001), Struhsaker (1977, 1978, 1980, 1981a, 1988), Struhsaker & Leland (1988), Struhsaker & Pope (1991), Thomas (1991), Tweheyo & Obua (2001), Uehara & Lhobe (1998), Worch (2001).

Figures

69. Owl-faced Monkey (Cercopithecus hamlyni), 70. Lesula (Cercopithecus lomamiensis), 71. Spot-nosed Monkey (Cercopithecus petaurista), 72. Red-bellied Monkey (Cercopithecus erythrogaster), 73. Sclater’s Monkey (Cercopithecus sclateri), 74. Red-eared Monkey (Cercopithecus erythrotis), 75. Mustached Monkey (Cercopithecus cephus), 76. Red-tailed Monkey (Cercopithecus ascanius)

Subspecies and Distribution. C.a.ascaniusAudebert,1799—SWDRCongo(SoftheCongoandKasairivers)andNAngola(Sboundaries¢.8°SandElimitatc.15°E);furtherEisanapparenthybridzonewiththesubspeciesatrinasusbuttheboundariesareuncertain. C.a.atrinasusMachado,1965—NEAngola,knownonlyfromasmallareaaroundthetypelocalityintheNWcorneroftheLundaDistrict,aroundtheWambaRiver;ithasbeenmappedfromc.8°-9°§,c.18°-18°30’E. C.a.katangaeL.onnberg,1919—SDRCongo(mainlybetweentheKasaiandLualabarivers),NWZambia,andNAngola(to11°S,17°E,exceptforthesmallsubspeciesatrinasusenclave). C.a.schmidtiMatschie,1892—DRCongo(EoftheLualabaRiver)extendingintoUganda,Rwanda,WBurundi,SWKenya,andWTanzania;NoftheCongoRiver,itextendsNandWoftheUbangiRiverintotheCentralAfricanRepublicandSSouthSudan. C. a. whiteside: Thomas, 1909 — DR Congo, between the Congo and the Kasai-Sankuru rivers. Its border with the subspecies katangaeis a little south of the Sankuru, with intermediates occurring between the Lualaba and Lomami rivers.