Survey and census of the hoolock gibbon in West Garo Hills, Northeast India

Abstract

ABSTRACT. During a long-term study on the hoolock gibbon in Northeast India, a detailed survey was made in West Garo Hills District of the Meghalaya, India from July 1985 to March 1987. Approximately 5,075 km 2 of the area was covered. Groups and individuals were counted in 32 localities (812 km2). Interestingly only 1,395 ha was the actual forest area occupied by these gibbons. Fortytwo family groups and four floating individuals of gibbons made up the total count. Of these the adult males and females comprised of nearly 67 ~ while the sub-adults, juveniles, and infants were 6 Yo, 12 ~, and 15 %, respectively. Each family group's territory ranged from 14 to 55 ha. Of the 32 localities only 6 had more than one family group. The present paper deals with the diminishing habitats for these gibbons. The discussion is based on the available small forest patches throughout the district (a common feature for the whole of Northeast India) surrounded by bare hills due to shifting cultivation. A strategy for conservation is also outlined.

Survey and Census of Hoolock Gibbon (Hoolock hoolock) in the Inner-Line Reserve Forest and the Adjoining Areas of Cachar District, Assam, India

“…hoolock are monogamous and maintain a social network within a group and social proximity with neighbouring groups of the same species [Alfred and Sati, 1990]; these authors also reported that a typical family group consists of a mated pair and 1-3 immature offspring. However, solitary individuals were also found near an existing group [Alfred and Sati, 1990]. During the present study, 1 solitary subadult (male) individual was found.…”

“…a mean group size of 3.6 individuals for 9 groups, is closely comparable to other studies conducted in different parts of the H. hoolock distribution range, as reported in Kumar et al [2009], i.e. 3.2 individuals for 24 groups and 3.4 for 7 groups [Tilson, 1979], 3.1 for 8 groups and 3.0 for 14 groups [Choudhury, 1990[Choudhury, , 1991 in Assam, 3-3.2 for 6-10 groups [Mukherjee, 1982], 2.1 for 34 groups [Gupta, 1994] in Tripura, 3.0 individuals for 42 groups [Alfred and Sati, 1990] in Meghalaya, 3.5 for 6 groups [Gittins and Tilson, 1984], 2.3 for 5 groups and 2.9 for 15 groups [Ahsan, 1984[Ahsan, , 1994, and 2.9 for 13 groups [Feeroz and Islam, 1992] in Bangladesh ( table 2 ).…”

Diversity, habitat preferences, and conservation of the primates of Southern Assam, India: The story of a primate paradise

“…With habitat fragmentation, the hardest hit species are the hoolock gibbons, Phayre's langurs, Bengal slow lorises, and capped langurs. It is projected that if jhum cultivation continues, the gibbons will eventually disappear from these places because they require continuous canopy in order to thrive (Alfred and Sati, 1990;Gupta and Kumar, 1994;Mukherjee et al, 1992).…”

“…It is one of the most extensively studied primates, and an extensive literature is available on the animal from various regions of northeast India (Alfred and Sati, 1990;Choudhury, 1990aChoudhury, , 2000bChoudhury, , 2006bChoudhury, , 2009aChoudhury, , 2009bMukherjee et al, 1992).…”

Survey of Hylobates agilis albibarbis in a logged peat-swamp forest: Sabangau catchment, Central Kalimantan

“…For gibbon surveys, researchers more frequently use auditory as opposed to visual cues (but see Alfred and Sati 1990). Haimoff et al (1986) located 20 groups during a survey of black-crested gibbons (Nomascus concolor) through auditory cues, only six of which were sighted.…”