Why are so many migratory birds dying across Rajasthan? Surmises range from avian flu, to increased salinity of water among others.
Rajasthan's winter habitats of migratory birds from Eurasia have witnessed a massive tragedy during the last five days. In Jaipur district's Sambhar Lake, tourists stumbled upon thousands of dead migratory birds.
Initial comments from experts in media reports point that the reason of death could be habitat-related.
Another mysterious calamity unfolded in Jodhpur district, which attracts migratory birds, especially demoiselle cranes. These are locally known as ‘kurjan’ and are even mentioned in Rajasthani folk songs.
The large number of bird deaths has stunned the locals and the local media, and many believe that such a high number of dead birds is a first.
Birds of nearly 15 species seem to have been affected and these include Flamingos, Garganey, Gulls, Northern Shoveller, Brahminy Duck, Pied Avocet, Kentish Plover Tufted Duck, Waders, Common Coots, Black Winged Stilts, Northern Shovelers, Ruddy Shelducks among others.
According to photographs taken by a journalist named Vikas Chaudhary, who has documented the tragedy, in Sambhar, India's largest inland saltwater lake which is a vital wetland for migratory birds, the toll is expected to cross 8,000.
Media reports speculate this number to be around 5,000, and the number of dead birds found at Sambhar Lake in Jaipur district, is between 1,500 and 2,000, as per different media reports.
Early speculations on the reasons behind the bird deaths pointed to avian influenza as being the prime reason. Experts, however, also pointed to toxicity and growing salt content in the water, in addition to bacterial and viral infections.
Thousands of dead birds have been buried in mass graves in Jaipur district, according to Down to Earth.
To arrive at the cause of the deaths, samples were sent to labs in Bhopal and Ludhiana. Birds found alive are being attended to by the forest department and viscera reports are awaited.
The Hindu quoted R G Ujjwal, nodal officer, animal husbandry department, as saying: “At initial examination, we did not find any sort of secretion from the birds, which is a giveaway in the cases of bird flu.”
According to some experts, the other possible reasons behind the calamity could be: contamination in the water, increased salinity of the water (where the salt concentration in the water affects the blood, leading to slow blood flow and ceasing of brain activity).
According to this report, an unnamed official said:
It doesn’t seem like it’s a virus. Birds are migrating earlier than usual, such as red crested pochard which were found in Bharatpur in mid-September — at least one-and-a-half months before their usual migratory time. However, the temperature here may still not be conducive for their survival and the weaker birds are dying. These seem like habitat-related deaths…
Jaipur’s Sambhar Lake is a destination for birds which roost here till March. The number of flamingos hosted, according to experts quoted in reports, is 50,000 and of waders — 100,000. Forest department staff and local villagers are scrambling for reasons.
The expected number of demoiselle cranes or ‘kurjan’ in Jodhpur, Bikaner and Nagaur is 35,000. Many of these, according to Dau Lal Bohra, an ornithologist quoted in a TOI report, are tagged birds under Crane Working Group of Eurasia (CWGE)'s ‘1,000 cranes project’.
“I have never seen such a thing in 40 years of my service in the forest department. First I thought it could be because of the hail, but that occurs every year. There is no chemical waste in this water either,” said Ramesh Chandra Daroga, a local working with the forest department.
Experts from a laboratory in Ludhiana have said they “have found both poisoning and diseases as causes of death” . The source of poisoning, according to experts, could be chemically treated seeds from nearby fields.