Context:

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

Wings Over Chilika: Early Arrival of 50 Migratory Birds

• Wildlife officials in the state 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.
• The early onset of winter in their native habitats could have prompted the birds to fly millions of kilometers to descend on Chilika, even though colder temperatures have not yet taken hold. 
• Migratory birds, mostly from beyond the Himalayas in Northern Eurasia, the Caspian region, Siberia, Kazakhstan, Lake Baikal and the remote areas of Russia and neighboring countries visit the Chilika every winter and start their homeward journey before the onset of summer.
• Northern shovelers, ruffs, godwits, plovers, gadwalls and a variety of migratory birds arrive in large numbers. 

Why do migratory birds arrive early at Chilika Lake?

• Natural disasters in the Himalayan regions, including Uttarakhand and Sikkim flash floods, Pushed them further south early.
• 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.
• Climate change leading to changes in weather patterns impacting migration patterns.
• Experts cited the Russia-Ukraine war as another possible reason. 

Asian Migratory Bird Flyway

• Five flyways cover Asia, The Asian-East African, the Central Asian, the East Asian-Australasian, the West Pacific and the African-Eurasian.

• The Central Asian Flyway starts from the northern breeding grounds of water birds in Siberia and leads across Asia to the Indian subcontinent. Little has been published about birds using this flyway. 
• Chilka Lake lies on the central Asian flyway, It is the largest wintering ground for migratory birds on the Indian sub-continent. 

Source: Down to Earth