Jessore District (22o 54’N and 89 o13’E) and a deltaic wide alluvial plain between the Hoogly and the Padma rivers. It comprises an area of about 259 km2 with about 570 people per km2 (Bari, 1979), and there are about 25 villages or village clusters of which only five are inhabited by the Hanumans. The maximum summer temperature in June varies from 24o to 33o C. The mean lowest temperature was 11o C in January. The annual rainfall varies from 1,524 mm to 1,752 mm and the average RH is 78% (Bari, 1979). The coconut (Cocus nucifera), betel nut (Areca catchu), date palm (Phoenix sylvestris), mango (Mangifera indica), debderu (Polyalthia longifolia) and jackfruit (Artocarpus heterophyllus) are the important plants. The mangrove species ora (Sonneratia acida) mainly grows along the bank of the Harihar river that cuts across the Keshabpur market into two parts. The river receives tidal water from the Sundarbans mangrove forest, the southwest corner of Bangladesh. The chief agricultural crops of the area are paddy (Oryza sativa), jute (Corchorus spp.), wheat (Triticum sp.), sesamum (sesamum indicum), pulses (lentil [Lens culinare], pea [Pisum sativum], gram [Cicer aritinum], chick pea [Lathyrus sativus]), tomato (Lycopersicon aperculella), potato (Solanum tuberosum) and betel-leaf (Piper betel).
The group-size and composition, age-sex ratios and relationships have been determined on the basis of fieldwork conducted between July and September 1981, when three bisexual groups were monitored. The Hanumans were categorised into adult males, adult females, juveniles and infants (Southwick et al., 1961a). The activity patterns of the troops were recorded through scan sampling methods (Altmann, 1974) on focal animals. Different activities performed by the Hanumans were noted at set time of 5 min intervals. Usually, 4 to 10 individuals were recorded in each scan and 3 to 12 scans were made in each hr, and the maximum scans were 151 in a day. During July 1981, data were gathered from 0600 to 1800 hrs with almost no or little break. In August and September, data were collected from 0600 to 1800 hrs with an hour break generally between 1200 and 1400 hrs. All data were gathered through direct observations. A pair of 10×50 mm binoculars were used in this work when needed. The following activities were considered for the present study. Rest: Leaning or setting down its body against a branch or an object, or lying down or sleeping. Move: Locomoting, it was sometimes difficult to decide whether a young (juvenile or infant) was moving or playing; when the movement was sporadic or non-directional it was recorded as playing. Sit: Not moving, resting either on its arms or legs but observing its surroundings. Social groom: Actively scratching, picking up parasites, debris, or fur of another one or itself being groomed by another individual. Self-groom: Doing active grooming or scratching itself. Play: Chasing, wrestling, stalking, pulling, running, or hanging from the branch of a tree. Feed: Active manipulation of a potential food source, ingesting or masticating food. As the Hanumans are normally static when feeding, the act was recorded as moving when the individual was simultaneously moving and masticating.