BEHAVIORAL PATTERNS AND CONSERVATION OF CAPPED LANGUR (TRACHYPITHECUS PILEATUS) OF MADHUPUR NATIONAL PARK, TANGAIL, BANGLADESH

Abstract

A study was carried out on ‘Behavioral patterns and conservation of Capped Langur (Trachypithecus pileatus) at Madhupur National Park in Tangail of Bangladesh’ during April 2015 to June 2018 (population census did during April 2015 to March 2016, data on behavioral patterns and diet were collected from January 2016 to December 2017 and conservation threats during July 2017 to June 2018). The aim of this study was to find out the total number of individuals, behavioral activities, diet, human-langur conflict and conservation threats of Capped Langur (Trachypithecus pileatus) in the Park. A total of 154 individuals of 18 groups and one isolated adult male (AM) were recorded. The group size ranged from 3 to 14 (8.6 ± 3.4) individuals. Among the 155 individuals (including isolated AM), 51% were adults and 49% immatures (sub-adult, juvenile and infant). Female was the highest (58.1%) in the total population. The ratio of adult male and female was 1:2.8, adult and non-adult 1:0.96. Four types of group structures (i.e., one-male, uni-male uni-female, unimale multi-female and multi-male multi-female) were recorded. The Langur started their activities before sunrise except in the month of May and June. The duration of the diurnal total active period ranged from 665 min. to 795 min. (716.67 ± 41.41 min., n=12) in a day and it was the highest (795 min.) in August and the lowest (665 min.) in December. Langur spent the highest time in resting (32.68%), followed by foraging and feeding (28.51%), sleeping (18.15%), traveling (11.11%) etc. In a day, the adult-male spent maximum time (29.44%) in resting but adult-females for feeding (36.18% time). Resting time (35.78%) was the highest in monsoon and the lowest (28.55%) in summer, foraging and feeding was the highest in winter (29.96%) but the lowest during monsoon (27.73%), traveling was the highest in monsoon (15.05%) and the lowest in summer (8.23%), sleeping was the highest in summer (25.44%) but the lowest in monsoon (11.54%) and playing was the highest in winter (8.39%) and the lowest in monsoon (6.55%). There was a significant relationship between resting and traveling with average temperature and rainfall. The highest time spent in mating was recorded (68.18%) in the morning (0600 hr to 0930 hr) but the lowest (31.82%) in the afternoon (1400 hr to 1900 hr). Langur used 0 - 18 m (9.14 ± 4.5 m, n=288) height during feeding but during traveling, the substrate height ranged from 0 - 27 m. (16.03 ± 7.9 m, n=35). Langurs preferred to use canopy bridge for traveling but during long canopy gap they used forest floor. The daily path length varied from 102.76 to 1054.62 m. (388.46 ± 271.41 m., n=74), the size of which depended on the availability of the food plants. The food items were leaves (tender leaves, young leaves and mature leaves), fruit, bud, flower, seed and shoot, of which leaves were highly preferred (63.55%). A total of 82 food plant species (58 trees, shrubs 5, climber 18 and 1 parasitic plant) were recognized. The Langur highly damaged the crops in homestead areas (88%) than cultivated areas. Crops raided were the highest in winter (69%). In homestead areas, crops, fruits, leaves, flowers, shoot and vegetables were raided, of which fruits were the highest (52%) preference. Habitat destruction, forest encroachment, illegal logging for timber and fuelwood, forest fire, hunting, road accident, electrocution and hyper-enthusiastic tourist activities were the major conservation threats for this species in Madhupur National Park. Avoiding monoculture practices, enforcement of laws to reduce illegal logging, avoiding construction of roads inside the forest, using insulated electric power line inside the forest, creating speed breakers on the highway, establishing artificial canopy bridges over the highway and by controlling hyperenthusiastic tourists activities may reduce the threats and mortality rates of primates especially, Capped Langur in the Madhupur National Park.