Hoolock Gibbon : Boon or boor ?

Rahul Ashem *

Hoolock Gibbon

There's a little riddle for readers... I am a tailless monkey, black colour for males and golden blonde for my opposite sex. I was first discovered in the Lohit district of Arunachal Pradesh (Groves, 1972; Giessman, Brockelman and Mootnick). Either you catch me in the land of Kunfu Panda or to the East of Chindwin River in Myanmar... Here goes the hint—the only ape found in the Indian sub continent?

Out of the six primates (Capped Langur, Rhesus Macaque, Northern Pigtailed Macque, Assamese Macaque, Slow Loris and HooIock Gibbon) present in the north eastern hot spots, Hoolock Gibbon is the only ape that stands tall in the context of the Indian sub-continent; a frugivorous brachiator and territorial species living mostly on the top of the canopy. Some might have seen, some heard and some not interested. As the name suggests, Hoolock Gibbon includes in Schedule 1 of the Wildlife Protection Act of 1972, categorised as endangered on the IUCN Red List, the same rate as tiger. The species can also be qualified for the indicator of the stability of the ecosystem.

Millions of species got certificate for the prize entitled "EXTINCT." The process is still continuing and many more are ready for the 'survival of the fittest'. On the land of Sangai, the number of species decreases due to increment of the weed species—paragrass (times of India 2011). The grass expands its habitat and destroys the food habit of the animal.

Like the case in the land of Rhino and land of Tiger, the park area was invaded by Mimosa invisa which is toxic to herbivores was once cleared up by the Kaziranga staff with the help of Wildlife Institute of India (WII). Lantana camera was removed from the land of Tigers by using cut root stock method which involves not only removal of clumps by cut root stock method and drying the dumps by placing the cut root stock up with aerial portions down and then burning the dried clumps.

Paragrass is monocotic angiosperms and there must be an easy way to eliminate it from the land of Sangai.

Hoolock Gibbon generally known as Hylobates or Tree dwellers (now Bunopithecus) are small anthropoid apes found only in the north eastern States of India. The genus "Hoolock" is represented by one species. According to Groves (1972) who documented the racial variation in colour on the opposite banks of the river Chhindwin in Myanmar divide the animal into two sub genus—Western hoolock gibbon (Hoolock hoolock hoolock) and Eestern Hoolock Gibbon (Hoolock hoolock leuconedys).

Western hoolock gibbons are jet black with perputial tuft black, white brow streaks close together connected by white hair. The hair of Female hand and feet are generally the same colour as the body hair but there is a black fringe on the fingers, toes and on the upper surface of the hands. Females have distinct central part in the head hair. So far, the distribution of Western Hoolock Gibbon is in India (all the nonh east States), Bangladesh and west of the Chhindwin river of Myanmar.

Eastern Hoolock Gibbons are black with brown overlay, perputial tuft white, brow streaks well separated with no white hair in between. The female crown hair grows slightly upwards and toward the nape of the neck and is parted down the middle and their hands and feet distinctly lighter than the male parts. The animai is scattered in India (oniy in the Lohit district of Arunachal Pradesh), China and East of Chhindwin River in Myanmar.

The sub genus is characterised by 38 diploid chromosome numbers (Prouty et aI, 1983). The animal produce bel canto growl vocalisation, the only gibbon species to do so, rehearsal mostly during the dawn and dusk time. Sometimes, while on ground or along the biggest branches they can walk on two legs. In fact gibbons are the only anthropoid apes that can walk truly bipedally, other tend to walk on all three—Chimpanzee, Gorilia and Orangutan.

There is lack of report on the survey of the existence of this mammal in Manipur. Like the festival, different kinds of culture are born here, the animal might be born in some or beatwise through forest trails, paths and roads covering at least 15-20% of the total forest area. Transects were laid in a stratified random manner to cover all the representative areas of the forest (Muller and Dombois and Ellenberg, 1974). Surveys were carried out on foot and whenever gibbon groups were sighted, record the colour pattern, group size, and age and sex composition. Approximate location of group on map, nearest landmark and the lat-long-altitude were recorded for every sighting with the help of GPS (global positioning system).

Survey procedures were developed to maximise and standardise the information to be gathered within the survey area. The habitat or forest type of each area were recorded as mixed, single dominated forest, broad leaf or deciduous.

Extension of occurrence and areas of occupancy were calculated as defined by the IUCN Red list criteria's and categories. The biomass of the animal can also be calculated by using the average body weight of adult males and females and multiplying it by the respective individual density.

Hoolock Gibbon is scientifically regarded as seed dispersers because of the frugitarian style of habit in nature. The common diet are ripe fruits with some flowers, leaves and shoot; sometimes depends on small Insecta for stomach tonic. Kadam (Anthocephallus cadamba); outenga (dillenia spp) and bamboos suited best for this mammal.

The animal gives birth to young ones in any of this tree species due to its high canopy cover, provident food or any threats from the ground floor. Females give birth to one offspring every two years. Infants coats are grey white with a yellow tinge (Mc Cann, 1933). They eventually turn black. At puberty, females turn pale while males remain black throughout life.

The natality graph of the animal leads to decline in the population of the animal or the mortality rate or the animal being killed are of female elements or is due to environmental factors like habitat degradation (rapid population growth); over exploitation (removal of timber, fuel, fodder and other commercially important species replacing the weaker ones); slash and burn cultivation (jhum cultivation leads to degradation of forest land and worsening of the soil conditions) or by the factors of that Hoolock Gibbon is a taboo to the tribes of Digaru, Mishmi, Idu Mishmi and Khamti of Arunachal Pradesh.

They believed the animal as their forefathers and living nearby for their good fortune. They even do not watch when the animal dies and falls on the ground, if they watch, it will bring ill-starred. Except the gibbon, the people hunt other primates found in the region. The same tune sang in every corner of north eastern States. They also collect the skin for decoration or other household purposes. With no fresh recruitment, the population may be condemned to extinction.

Earlier Gibbons in India were calculated as Western Hoolock Gibbon because of the special appearance of the population of Eastern Hoolock Gibbon or to the similar morphological characters with the Western Hoolock Gibbon as the animal are shy and live almost on the apex of the canopy.

A detailed study is required to evaluate the population status of the eastern species in India. Broad survey method is also useful technique for obtaining information on the presence and relative numbers of a species population in particular areas. Secondary information can also be collected through interviewing the local villagers !

(Save the animal...Save the ecosystem services)