Climate Change

Migratory birds arrive in Odisha’s Chilika before winter; is climate change to blame?

Early onset of winter in their native habitats could have prompted the birds to fly & descend in Chilika this early

By Hrusikesh Mohanty
Published: Wednesday 11 October 2023
Photo: Hrusikesh Mohanty__

Migratory birds have started their annual journey to Chilika —India’s largest waterbird habitat in Odisha — ahead of winter this year.

Wildlife officials in the state have reported the sighting of approximately 50 migratory birds, including ducks and wigeon species, within the Nalabana bird sanctuary area inside the blue lagoon on October 7, 2023.

While patrolling across the vast expanse of the 1,100-square-kilometre lake, the officials observed several birds gliding through the skies in the vicinity of Chilika without descending into the lake’s waters.

They might descend into the lake once the water level recedes in the wetland, said Amlan Nayak, divisional forest officer (DFO), Chilika Wildlife Division, Odisha government.

According to ornithologists, the arrival of the migratory birds to Chilika is not very early this year. Last year, the first batch of migratory birds was sighted in the second week of October when the temperature was above 30 degrees Celsius. However, this year, they arrived during the first week of October when temperatures in the region and its surroundings ranged from 33°C-35°C.

The early onset of winter in their native habitats could have prompted the birds to fly millions of kilometres to descend on Chilika, even though colder temperatures have not yet taken hold in the state, said the DFO.

Migratory birds, mostly from beyond the Himalayas in Northern Eurasia, the Caspian region, Siberia, Kazakhstan, Lake Baikal and the remote areas of Russia and neighbouring countries visit the Chilika every winter and start their homeward journey before the onset of summer.

The recent natural disasters in the Himalayan regions, including Uttarakhand and Sikkim flash floods, might have pushed them to fly to Chilika, said Jitshatru Mohanty, a retired senior forest officer.

Food availability is another factor that influences bird migration. The scarcity of food in their native habitats likely compelled these birds to embark on long journeys in search of suitable wetlands, with Chilika being one of their preferred destinations, said Sudhakar Mohapatra, retired senior forest officer and an ornithologist.

In 2022, the first batch of migratory birds made their way to the lake despite the temperature in the second week of October soaring above 30°C, he said.

The migratory birds that arrive at Chilika are well-adapted to the local climate. However, they begin their homeward journey as the temperature reaches around 40°C, said an ornithologist from the Bombay Natural History Society.

In the last winter, as many as 1,131,929 birds of 184 different species had visited Chilika. This included 1,093,049 migratory birds from 105 various species and 38,859 resident birds belonging to 79 species.

With stringent protection measures in place, wildlife officials are anticipating a substantial influx of birds this season.

The DFO said they have set up as many as 20 temporary camps in the vulnerable areas to prevent bird poaching during the season. Besides wildlife staff, an additional 50 locals have been hired on a temporary nasis.The department has also hired around a dozen boats to patrol the lake, he said.

The camps have started functioning from October 1 and will continue till the end of March. Patrolling and awareness drives to prevent bird poaching was also launched in different villages around the lake, he added.

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