Current status of Western Hoolock Gibbon Hoolock hillock Harlan in West Garo Hills, Meghalaya, India

Abstract

A rapid status survey of Hoolock Gibbon was carried out in 28 localities of West Garo Hills, Meghalaya in March-April 2007. These 28 were among the 32 localities surveyed previously during 1985-1987 by Alfred & Sati (1990). Gibbons were found in only 15 of the 28 localities. Only 25 groups of gibbon totaling 82 individuals were observed, compared to 36 groups with 111 individuals recorded at the same sites 20 years ago. Adults comprised nearly 61% of the total individuals, followed by infants 16%, juveniles 13% and sub-adults 10%. While the proportion in the adult age class had decreased from 67% in 1985-87, the proportion of individuals in all other age classes showed slight increase. The sex ratio of males: females was 1:1 for adults as well as sub-adults, which was the same as in 1985-87 survey. The modal group size was three (44% of groups) as before. However, the next frequent group size was four (28% of groups), whereas previously the second most frequent group size was two (30% of groups). Twenty percent of groups had two individuals and 8% of groups comprised of five individuals. The Hoolock Gibbon population in the West Garo Hills showed a decreasing trend of 26.2% (82 individuals out of 111 individuals) in 28 localities, when compared with the previously documented numbers. The major reasons of their decline are anthropogenic disturbances such as tree felling for domestic and commercial uses; intermittent cutting of new forest patches for fresh jhum cultivation, often resulting into canopy gaps as well as habitat loss; livestock grazing and poaching.