Know the avian guests who no longer visit Odisha’s Chilika

Bhubaneswar: Come winter and Odisha’s Chilika turns into a birder’s paradise with migratory birds of different species flocking to the lake for their annual sojourn.

This year’s bird census at Chilika pegged their number at 8,93,390 as against 9,47,119 in 2017. “The number has been fluctuating between 7 lakh and 9 lakh for the last 10 years,” said Divisional Forest Officer, Chilika, Bikash R Dash. He attributed the fall to unseasonal rain and rise in the water level in the lake. However, it is not the number but the decline in certain species of birds, which is a matter of concern.

In a conversation with Odisha Sun Times, Dr S. Balachandran, deputy director of Bombay Natural History Society (BNHS), which takes part in the annual census of migratory birds in Chilika, said, “The lake can accommodate around 10 million birds, including the local and migratory ones. If we look at the pattern for the last 10 years, there has been a gradual decline in some species of birds visiting the lake.”

The only constant has been the fluctuation in the number of shorebirds or waders. “These birds usually rest along the shores where the depth of water is 2-3 inches. This year, since the water level rose, their number was less. We are all aware of climatic changes and birds are most sensitive to any alternation in the ecosystem,” he explained.

Spoon-billed sandpiper, a wader, which has not been seen at Chilika for the last 10 years, is now a critically-endangered species, he said, adding that less than 200 pairs of this bird are left world over. Likewise, the number of Siberian cranes too has critically dwindled.

Three most common types of birds found in Chilika, according to Balachandran, are waders, dabbling ducks and diving duck.  Among them, dabbling ducks like gadwall and northern pintails are in good numbers because they can adjust to almost any condition. “Diving ducks have also seen a drastic decline but the reasons are yet to be known. Common poachers, a diving duck, whose number was more than a lakh in 2001 in Chilika has come down to less than 5000. They fall in the vulnerable category now,” he said.

Throwing light on the importance of these migratory birds for the ecosystem, he said, “These birds are also a reason why Chilika is so beautiful and rich. They nourish the soil with their excreta and groom the vegetation in and around the lake which gives ample space for the aquatic animals to breathe and breed. The fishermen often throw dead fishes in the lake, which birds like seagulls gobble up. The ecosystem works by itself where every animal plays an important role. Hindrances in the same will surely create problems,” he added.

Migratory birds fly from the Siberian region of Russia and the Yellow Sea in China is the common stop for these birds, Balachandran further said, hinting at the deteriorating condition of the sea that has also led to the decline in certain species since they no longer find a spot to rest in between. “From Central Asia to the Yellow Sea and from there to all different destinations including Mongolia, Australia and the Indian subcontinent, these birds fly over to around 29 countries. The condition of this route determines how many birds reach their winter destination,” he said.

Speaking on the solutions found, he brought up the flyway approach the entire team of researchers have come up with. “This approach deals with the route of these migratory birds. We are trying to coordinate with all the countries involved so as to provide a suitable environment to these birds, especially improving the quality of Yellow Sea in China. Besides, people residing in areas around Chilika and other hotspots of these birds, must keep it clean and avoid disturbing the winged guests. Proper implementation of the Climate Protection Act, 2013, can also bring about a huge difference,” he added.