Civic workers bury birds at Sambhar Lake. (PTI) Civic workers bury birds at Sambhar Lake. (PTI)

On Thursday, the toll neared 5,000. By Friday evening, over 8,000 had been buried.

The dead birds were first spotted five days ago by visitors at Rajasthan’s Sambhar Lake, India’s largest inland salt water lake, nearly 80 km southwest of Jaipur. Since then, state agencies have buried a total of 8,065 birds, from 25 different species including migratory, and rescued 165. Bird watchers fear the final toll may be much higher, considering the size of the lake.

But the big worry, say experts, is that they have still not been able to find the cause of these deaths.

So much so that Chief Minister Ashok Gehlot has ordered a rescue centre to be set up at the site, Minister of State for Forests (Independent Charge) Sukhram Vishnoi has rushed to Sambhar, and the Rajasthan High Court has taken suo motu cognizance of the crisis.

On Friday, the government listed the possible reasons behind the deaths before a division bench headed by Chief Justice of Rajasthan High Court, Indrajit Mahanty. On the list were viral infection; toxicity, as a new area of the lake has filled up, leading to higher concentration of salts along the edges; bacteriological infection; and, stress caused by competition for resources that have grown scarce due to high temperature and water levels.

But officials admit there are no clear answers, yet.

Sambhar Lake: A dead bird at the Sambhar Salt Lake in Rajasthan, Monday. (PTI) Sambhar Lake: A dead bird at the Sambhar Salt Lake in Rajasthan, Monday. (PTI)

Rajasthan’s Animal Husbandry director Sailesh Sharma said the National Institute of High Security Animal Diseases (NIHSAD) in Bhopal has ruled out bird flu after carrying out tests on samples. “Other labs will continue the investigation,” Sharma said.

Dr A K Kataria of the Rajasthan University of Veterinary and Animal Sciences (RAJUVAS), who reached the lake Thursday, pointed to botulism, a paralytic and often fatal disease caused by ingestion of toxins. According to officials at the site, the birds suffered from limb paralysis and diarrhoea.

Kataria also said that the carcasses need to be buried “immediately” to prevent the infection from spreading to other birds.

“Never have so many birds died at Sambhar,” said Dr Joy Gardner, who heads the NGO Hope and Beyond that is working at the site. “Also, there are many areas where we haven’t reached yet. So the final toll may be much higher.”

Experts from the Bombay Natural History Society (BNHS), Wildlife Institute of India (WII) and Salim Ali Centre for Ornithology and Natural History (SACON) are also at the site. WII’s Dr Anju Baroth said the salinity in the water is high “but no other adulteration has been found”.

Officials said the Rajasthan State Pollution Control Board and Sambhar Salts Ltd, a subsidiary of central PSU Hindustan Salts Ltd, have also collected water samples from the lake.

Additional Advocate General Ganesh Parihar said the government told the court that “samples from the site have been sent to multiple labs” and that “further preventive action is only possible after the receipt of medical reports”.

The government also pointed to delay in collecting the carcasses because of mud, water, and the large area — “around 15-kilometre length out of which 12-kilometre area is where birds have died”.

Meanwhile, the district collectors of Jaipur, Ajmer and Nagaur have received a grim directive: Take up the disposal of carcasses as a campaign and ensure appropriate disposal.

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