About Macaca assamensis (McClelland, 1840)
The Assam macaque (Macaca assamensis) has pelage ranging from yellowish-grey to dark brown. Its facial skin is dark brownish to purplish. A dark fringe of hair along its cheeks grows backwards toward the ears, and the hair on the top of its head is parted in the middle. The shoulders, head, and arms are typically paler than its greyish hindquarters. It has a short tail covered in thick hair. Head-to-body length ranges from 51 to 73.5 cm (20.1 to 28.9 in), the tail measures 15 to 30 cm (5.9 to 11.8 in) long, and adult individuals weigh 5 to 10 kg (11 to 22 lb).
In distribution, the Assam macaque is found east of the Kali Gandaki River in Nepal, at elevations between 200 and 1,800 m (660–5,910 ft). In northeastern India, it lives in tropical and subtropical semievergreen forests, dry deciduous forests, and montane forests up to 4,000 m (13,000 ft) in elevation. In Laos and Vietnam, it prefers elevations above 500 m (1,600 ft). It generally inhabits hilly areas above 1,000 m (3,300 ft), but also occurs in lowlands below this elevation in the wetter eastern part of its range, and at lower elevations in limestone karst forests.
Assam macaques are diurnal, and are both arboreal and terrestrial at times. They are omnivorous, feeding on fruits, leaves, invertebrates, and cereals. In 2002, 15 groups totaling 209 individual Assam macaques were recorded in Namdapha National Park, Arunachal Pradesh. In this area, the population had a group density of 1.11 individuals per 1 km² (0.39 sq mi), with an average group size of 13.93 individuals. During a 2007 survey in Nepal's Langtang National Park, a total of 213 Assam macaques were encountered across 9 groups in a 113 km² (44 sq mi) study area. Troop sizes ranged from 13 to 35 individuals, with a mean troop size of 23.66 individuals. The population breakdown was 31% adult females, 16% adult males, with the remaining individuals being young of various ages. In this surveyed population, Assam macaques preferred maize kernels, followed by potato tubers, and also raided cultivated fields of wheat, buckwheat, and millet.
