For birders who would regularly visit Pong wetlands, the recent mass death of over 2,400 birds across species has been a big blow. About 90% of the migratory birds which died were the endangered bar-headed geese. But what has deepened the sense of loss is the death of a rare visitor—long white-fronted goose—which had become an annual guest to the wetlands in the last four years. While not an endangered species, it was the only one of its kind which ventured into India from north and central Asia.
“It’s very sad that this individual goose is among the birds that have died. It’s quite a rare bird to find in India and would attract lot of bird watchers,” says KS Gopi Sundar, scientist, cranes and wetlands, National Conservation Foundation (NCF).
With samples from birds testing positive for avian influenza, Himachal Pradesh has become the fifth state after Rajasthan, Kerala, Haryana and Madhya Pradesh to confirm the presence of the virus. Bird flu is not new to India but what’s alarming is the large number of birds dying in a very short span of time. In Indore, for instance, there have been reports of as many as 50 crows dying overnight.
“The migratory birds are dying in December and January - months when they have been in the country for a while already. This suggests that the source is local and also suggests that the migratory birds did not carry the virus into the country. If they had, we would have witnessed deaths in October and November when the birds arrive, and when they are tired from their long flight. That current deaths are happening fast is suggestive of a virulent form of the virus and needs to be taken seriously,” explains Sundar.
While the influenza 'A' virus is common in the guts (intestine) of migratory waterfowls, the exact strain of the virus that is causing this mortality is still being examined, says Bivash Pandav, director of the Bombay Natural History Society (BNHS).
Meanwhile Pandav has a contrary view about the source of the virus. “Though the role of migratory birds in transmission of the high pathogenic avian influenza virus is still unclear, studies have confirmed that water birds across the world are predominant natural reservoirs of influenza viruses. This virus mutates rapidly and can be a pandemic threat to poultry. The potential of this virus to acquire consistent human to human transmissibility and cause a human pandemic cannot be ruled out,” he said.
During the last bird flu outbreak in 2006 that lasted till 2015, a large number of poultry animals were culled to limit the spread of the virus. This time, too, some states are considering taking such an action. Kerala, which reported the death of over 25,000 ducks, has already ordered the culling of chicken and ducks that may have been exposed to the dead birds in two districts.
On 3 January, the wildlife division of Ministry of Environment, Forest and Climate Change, issued a circular putting all the states on alert. The ministry has also urged a strict vigil on migratory and wetland birds. While the disease has mostly transmitted among poultry animals, recently it has also spread to wild birds and vice versa, the circular stated.
Meanwhile, the ministry circular and various birding groups have warned bird watchers to be especially careful since they throng the wetlands often. Among the advisory, the birdwatchers have been asked not to approach or touch ill or dead birds, and also not to enter the water body.
For bird conservation, such outbreaks can be damaging. “Most migratory birds congregate in relatively few wetlands. If there are rare birds or birds that are not necessarily rare, a virulent strain can knock off a significant part of the population,” Sundar says.