80 Per Cent Of Gharials Found In Chambal
In a preliminary field report, Dr. Jeffery W. Lang, Senior Advisor for The Gharial Ecology Project, provides a comprehensive view of the gharial population that inhabits the Chambal river.
Photo: Jeffery Lang.
According to Dr. Lang, “The Gharial Ecology radio telemetry project, parented by the Madras Crocodile Bank Trust was initiated in an effort to better understand the seasonal movement of gharials and in light of the unprecedented die-off in the National Chambal Sanctuary in the winter of 2007/08.”
The gharial (Gavialis gangeticus) is a large fish-eating crocodilian that inhabits South Asian rivers. Human encounters are rare, and gharials pose little danger to people, in contrast to other crocodiles such as the mugger or marsh crocodile, and the saltwater crocodile, both species found in India. The only viable, self-sustaining population of gharials is found in the Chambal river. The species is currently listed as ‘critically endangered’ on the IUCN Red List, and is scheduled to undergo a reassessment of its conservation status this year. In his report, Dr. Lang details the relevance of the recent count to the assessment that is currently underway.
The Gharial Ecology Project provides the biological basis for science-based conservation action to protect wild gharials in their natural habitat. A population count conducted from January to March 2017 revealed that at least 483 adult gharials inhabit the 414 km. National Chambal Sanctuary (NCS), including 72 males with gharas, and 411 females. This very conservative estimate is based on the nests counted at 26 sites throughout the entire 414 km. stretch of NCS, from Pali to the Yamuna confluence. Direct counts indicate that about 1300-1500 gharials live in NCS.
Dr. Lang articulates the importance of this large, breeding population in the protected, open river habitat stating that the number of gharials living in the NCS represent at least 80 per cent of the global gharial population, and nesting in the NCS represents 90 per cent of the global annual nesting of this species.
Photo: Jeffery Lang.
The collated data firmly establishes that the estimated gharial population is a single interbreeding population, seasonally inhabiting and breeding on the 414 km. stretch of the NCS. While it is significant to note that wild gharial sub-populations continue to exist at five other locations spread across India and Nepal, regular breeding showing substantial numbers has been documented at only two other localities — in Katerniaghat Sanctuary in India, and Chitwan National Park in Nepal.
The report strongly suggests that the reproductive frequency for Chambal gharials (percentage of reproductive females that nest annually) is close to, if not at 100 per cent. Such a nest count is a very conservative estimate of the number of adult females in the Chambal population. Therefore It becomes imperative that the Chambal gharial population be conserved. The main threats to gharials here are sand mining, water extraction, net fishing and major disruptions to natural river flow from dams and proposed river interlinking.
“In particular, sand mining has increased exponentially in the past two to three years, with mining occurring on an industrial scale at multiple sites, and village-level mining, with local tractors and trolleys evident at nearly all sand banks and sand areas along the river shoreline. This activity is concentrated on the Madhya Pradesh side, with lesser activity in Rajasthan, and considerably less sand mining on the Uttar Pradesh side of the NCS. Likewise, net fishing is occurring on the MP side to a much greater extent than on the UP or Rajasthan side of the NCS,” explains Dr. Lang.
A copy of the Field Report summarized here is available online at: academia.edu