Global Warming : Another Threat to the Endangered Gharials !

Braving the blistering May afternoons on the banks of Chambal River, a dedicated team of National Chambal Gharial sanctuary scan the sand mounds spread over a long patch of the river that flows into ravines. This long walk is actually the beginning of a very delicate exercise for the ex-situ conservation of   Gharial (Gavialis Gangeticus ) , a critically endangered reptile.  The scanning of sands includes the sighting of nests and counting of their numbers and then collection of  200 eggs. And all this takes almost a month’s time. Chambal is one of the few habitats left in the world for these reptiles. In May end, sanctuary staff are ready for the magic moment - the emergence of hatchlings from the egg.

Calling Mom from Beneath the Sand

The ex-situ conservation of Gharial assumes significance and is an extremely important exercise carried out from March when the Gharials lay their eggs to May when they crack the egg with their snout to see the world  . Despite over an estimated 10,000 eggs laid by this species of crocodile family every year, only about 2 % hatchlings survive. Shrinking habitat, illegal sand mining and other environmental issues make them further vulnerable. The eggs are laid by the reptiles in the month of March and have an incubation period of about 60 to 65 days.  The team led by Jyoti Dandotiya , a senior conservationist ,  collects  200 eggs  and  transports them  carefully to the hatching centre in Morena ,  a city nestled in Chambal ravines  almost 450 kms North of  the capital city of Bhopal . Once the eggs are collected,  they are placed beneath the sand brought from Chambal River. The nests made at the centre have the same temperature and moisture as it was recorded in the original nest from where they were collected about 10 to 15 days ago. 

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Once all the eggs  are  conserved, Jyoti and his team members  train their ears  to hear the feeble croaking sound of the mother- call coming out from the eggs placed beneath the sand. And as soon as the sound starts emanating ,the sand is immediately removed to let the ‘baby’ come out of the egg. “Its sheer bliss”, says Dandotiya.  In fact the  sanctuary staff  simply replicate an exercise that is carried out in the wild when the female Gharial would wait for the call   as she waits  in the river nearby . AS soon as  she hears the croaking sound , it slithers down to  the nest  to dig out the  sand and let the hatchlings come out. The hatchlings break the egg with an egg-tooth, said Dandotiya. In the hatching centre, the hatchlings are carefully quarantined. But in the wild, the moment a hatchling comes out from the nest, it slips down to the  water. “ The nests are made in such a way that  they are on the top of a slope to enable the  hatchlings to roll down to the water”,  said Dandotiya. But these days climate change has started affecting the already fragile life cycle of this endangered harmless creature.

No Study Yet for the Impact of Global Warming

For the past few years, say about a decade, Global warming has disturbed the  Gharial’s breeding  cycle. There was a time when they would lay eggs in March end when the day temperature starts going up. But   now Gharial lays eggs about 15 days in advance.  It has an incubation period of  about 60 to 65 days, so the  moments  of mother- call have also advanced  for about 15 days. The mother Gharial makes a nest close to the river bank on the top of the sand mound so that when the hatchlings come out, they can easily roll down to the river to reach the waters.  

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But thanks to the higher day temperature and uncertainty of rainfall, the river  shrinks early and shifts  away from the nesting site, Dandotiya said . There is always a risk of predators while the lizard –sized hatchlings travel a longer distance after coming  out from   eggs and reaching the river,  the conservationist said.  Besides,  the  sand bed is too hot for the hatchling that  is barely a few moments old  and it  succumbs  to high temperatures  even before reaching the river. However,  a  comprehensive study on the  possible impact of climate change  is yet  to take off, perhaps, anywhere in the world, claims Jailabdeen, a research scholar  from Madras Crocodile Bank Trust and Centre for Herpetology (MCBTCH). He is studying the reptile in Chambal.

High Mortality Leads to Decline in Population

Only about 2 % of reptiles survive in the wild   and there are mass casualties once the river is flooded in the monsoon in July.  Which is why the ex -situ conservation is important. The reptiles reared in the hatching centre of Morena are released in the river  in the winters when they attain a length of 1.20 meters in about 2 -year of period. Those who are still short of this length, they are released by the next winter.This is also the right time for the wildlife tourists to visit the sanctuary and do some great wildlife photography. At present there are 2176 Gharials in  the sanctuary  that is spread  across   the states of Madhya Pradesh, Uttar Pradesh and Rajasthan. The census of these Gharials takes place in winters when all the reptiles, irrespective of their shape and size come out of the river to bask in the sunlight and conserve energy. This is also the time when they mate and lay eggs in March , when the exercise of collection of eggs begins.