Rhinopithecus strykeri, Geissmann, 2011

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 : 729

129.

Stryker’s Snub-nosed Monkey

Rhinopithecus strykeri

French: Rhinopitheque de Stryker / German: Burma-Stumpfnase / Spanish: Rinopiteco de Birmania

Other common names: Burmese Snub-nosed Monkey, Myanmar Snub-nosed Monkey

Taxonomy. Rhinopithecus strykeri Geissmann et al., 2011 ,

26.43101° N, 98.38894° E (elevation 2815 m) in the Maw River area, northeastern Kachin State, in northeastern Myanmar.

R. strykeri is closely related to R. bietu. Monotypic.

Distribution. NE Myanmar (Salween-N’mai Hka divide in NE Kachin State, only around the Maw River, as far E as the Mts above the village of Chichitago, 26.31°-26.51° N and 98.34°-98.61° E) and S China (Gaolilgongshan National Nature Reserve, Yunnan Province).

Descriptive notes. Head—body ¢.55-5 cm (males) and c¢.54 cm (females), tail ¢.78 cm (males) and ¢.68 cm (females); weight c.14 kg (males) and c.8-5 kg (females). Fur of Stryker’s Snub-nosed Monkey is mostly black, with black or blackish ventral parts; limbs are all black or blackish. Crown has a thin, high, forward-curved crest of long, black hairs. There are protruding white ear tufts. Face is mostly naked and pale pink. Upperlips have whitish hairs on each side, and there is a distinct white beard. Perineal area is white. Tail is black and long (c.140% of head-body length). Stryker’s Snubnosed Monkey is most similar to the Yunnan Snub-nosed Monkey ( R. bieti ), from which it is distinguished by the total lack of white on underside and inner sides of limbs, lack of brown on temples, dark gray-brown forehead instead of buff, white whiskers instead of black, dark gray-brown hairs on cheeks instead of pure brown, shorter black hairs on backs of thighs instead of white, entirely pale pink facial skin, and a much longer tail (140% of head-body length rather than 100-130%).

Habitat. Steep mountainous areas in cool temperate rainforest and mixed temperate forests at elevations of 1720-3190 m and probably as high as 3660 m. Stryker’s Snub-nosed Monkey moves to high-elevation mixed temperate and conifer forests in summer (May—October) and to lower elevations in winter (November—April). It is sympatric with Shortridge’s Langur ( Trachypithecus shortridger), various macaques ( Macaca ), and most probably the Bengal Slow Loris (Nycticebus bengalensis) and the Eastern Hoolock Gibbon (Hoolock leuconedys).

Food and Feeding. Stryker’s Snub-nosed Monkeys eat bamboo shoots.

Breeding. There is no information available for this species.

Activity patterns. Stryker’s Snub-nosed Monkey is diurnal, arboreal, and terrestrial.

Movements, Home range and Social organization. Stryker’s Snub-nosed Monkeys have never been studied in the wild. Reports from the Maw River area indicated two groups of ¢.30 individuals, one of 60-80, one of ¢.80-100, and one of c.150, but these may have been the same groups in different phases offission and fusion.

Status and Conservation. CITES Appendix I. Classified as Critically Endangered on The IUCN Red List. The known population of Stryker’s Snub-nosed Monkey is estimated at 260-330 individuals. Its range is not more than ¢.273 km?Illegal hunting is the major threat (at least 13 individuals were hunted and killed in 2009), and hunting and habitat loss will probably increase in the near future because of the construction of dams and access roads for logging. In 2011, Stryker’s Snub-nosed Monkey was discovered in Gaoligongshan National Nature Reserve near Pianma, Nujiang Lisu Prefecture, Yunnan, at an elevation of 2546 m in border forest contiguous with Myanmar. No population estimate is available for China.

Bibliography. Geissmann, Ngwe Lwin et al. (2011), Geissmann, Momberg & Whitten (2012), Liedigk et al. (2012), Long Yongcheng et al. (2012).

Figures

122. Red-shanked Douc (Pygathrix nemaeus), 123. Gray-shanked Douc (Pygathrix cinerea), 124. Black-shanked Douc (Pygathrix nigripes), 125. Tonkin Snub-nosed Monkey (Rhinopithecus avunculus), 126. Yunnan Snub-nosed Monkey (Rhinopithecus bet), 127. Guizhou Snub-nosed Monkey (Rhinopithecus brelichi), 128. Golden Snub-nosed Monkey (Rhinopithecus roxellana), 129. Stryker’s Snub-nosed Monkey (Rhinopithecus strykeri), 130. Pig-tailed Langur (Simaas concolor), 131. Proboscis Monkey (Nasalis larvatus)

Distribution. NE Myanmar (Salween-N’mai Hka divide in NE Kachin State, only around the Maw River, as far E as the Mts above the village of Chichitago, 26.31°-26.51° N and 98.34°-98.61° E) and S China (Gaolilgongshan National Nature Reserve, Yunnan Province).