Sunday, January 4, 2009

Vanishing Species - The Gharial

An Article by Mohan Pai

The Gharial
Gavialis gangeticus
The Monarch of the Indian Rivers

Gharials float dead by the dozen in Chambal

Todays Indian Express, Bangalore edition (Feb. 20, 2008) has carried a report about the death of 90 Gharials only in the period last two months in the National Chambal Sanctuary, situated around the Chambal river and shared among the three states of Rajasthan, Uttar Pradesh and Madhya Pradesh. Reasons for their sudden death are yet to be established as The Chambal river is said to be the cleanest Indian river, but preliminary results point to high levels of heavy metals(lead and cadmium) in the blood leading to a reduction in body’s ability to fight bacteria, exposing them to infections.
The Gharial is listed in the Critically Endangered (CR) category of the IUCN Red Data Book. According to IUCN (International Union for Conservation of Nature and Natural Resources). The mature Gharial population in India stands at less than 200 reptiles. There is a clear decline of 58% as the same figure a decade ago was 436. Gharial Rehabilitation Project was started in 1975 with some hope for the survival of the Gharial but now with such a radical decline, it’s doubtful if the Gharial could be saved.
However, State officials say that the IUCN figure may be representing the Gharials in their natural habitat only. The estimated population of gharial is placed at 1,976. Lucknow’s Kukrail Gharial rehabilitation Centre (KGRC) is famous for the captive breeding of alligators. The only silver-lining is that the Gharial responds well to captive breeding so there is some hope.

Gharial belongs to the reptilian order of Crocodilia. The long, slender jaws, bulging eyes, and sleek olive-green trunk, distinguish the riverine gharial from the other two Indian species. The adult male has a hump at the end of the snout, resembling an earthen pot or ghara; hence the name Gharial. Gharials are often confused with muggars. Specimens over 7 m long existed but no very large specimen remain due to heavy hunting. In fact the gharial is one of the most seriously endangered Indian animals.

Formerly abundant in the major river systems of Nepal, India and Pakistan, the present remnant groups are mostly confined to a few isolated areas on the Ganga, Mahanadi and Brahmaputra rivers with Chambal Valley having the largest population.
One reason for the failure of the gharial to survive is its specialized habit requirements. Gharials inhabit deep pools (where fish are plentiful) in big rivers, using sandbanks for basking and nesting.
Gharials are almost exclisively fish-eaters and the narrow jawa are efficient far catching and swallowing fish. The swodlike jaws are jerked sideways to snap up a passing fish, which is then swallowed by several backward jerks of the head. Their fish-eating habits and timid nature render them harmless to man though it is said that breeding females will charge and bite intruders near the nest.
Gharials are social and live in groups usually made up of a single dominant male, several females and several sub-adults. As with other crocodilians, the young live apart after a one or two months nursery period. 40-80 eggs are usually laid, in nest-holes on river banks. Gharials may fail to breed where there is escessive disturbance.
The Government of India has, with aid from FAO/UNDP, initiated a long-term programme to save the three Indian crocodilians from the imminent threat of extinction. Artificial incubation of wild eggs (which raises normally low survival chances) and captive breeding has been the basis of this programme. Eight states are involved and sanctuaries and national parks have been constituted, the most extensive being 2500 km2 Chambal River National Gharial Sanctuary which involves U.P., M.P. And Rajasthan. Hundreds of captive-reared gharial, mugger and salt-water crocodiles have been released.

References: R. E. Hawkins - Encyclopedia of Indian Natural History, Wikipedia and Delhi Green

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