India is a vast and diverse country that provides habitat for a wide variety of migratory birds. Every year, hundreds of species flock to India to escape the harsh winters of their breeding grounds further north. India’s geographic location makes it an important stopover point along the Central Asian Flyway, one of the world’s major migratory bird routes. But exactly how many avian species make this epic journey to India each year?
What is bird migration?
Bird migration refers to the seasonal, usually north-south, movement of bird populations between their breeding and non-breeding ranges. It is an adaptation that allows birds to take advantage of favorable conditions and abundant resources during the summer months where they breed. When winter arrives, food becomes scarce and temperatures drop, prompting the birds to migrate to warmer regions where resources are more plentiful. This migratory pattern occurs in many bird species across the world.
There are many factors that trigger migration in birds. Changing temperatures and food availability provide cues that it is time to move. The decreasing daylight hours of late summer also let birds know winter is approaching. Birds prepare for migration by storing energy reserves and may make physiological changes as well. When the conditions are right, birds embark on their strenuous journeys, using skills like keen senses of direction and navigation.
Major flyways used by migratory birds in India
India lies along two major migratory flyways used by birds:
- The Central Asian Flyway (CAF) – This covers a large swath of Eurasia between the Arctic and Indian Oceans. Many waterbirds use the CAF on their migrations between Siberia, northern China, and southern Asia. India serves as an important wintering area for species using this flyway.
- The East Asian-Australasian Flyway (EAAF) – Stretching from Arctic Russia and North America to Australia and New Zealand, the EAAF encompasses migratory routes across East Asia and the Asia-Pacific region. Some birds wintering in India arrive via the western edge of this flyway.
In addition to these two major flyways, some seabirds and raptors reach India on other migratory routes from Europe and Africa. The Himalayas also act as an ecological barrier that funnels migratory birds traveling overland into India.
Categories of migratory birds in India
Many different types of birds migrate to and through India each year. They can be grouped into the following categories:
- Wetland birds – Herons, storks, cranes, geese, ducks, waders, gulls, terns
- Raptors – Eagles, hawks, falcons, harriers, kites, vultures, osprey
- Land birds – Thrushes, warblers, finches, buntings, sparrows, starlings
- Seabirds – Pelicans, gannets, shearwaters, skuas, phalaropes
The wetlands of India offer an abundance of habitat for migratory waterbirds arriving via the Central Asian Flyway. Prominent wetland stopovers include lakes, rivers, marshes, mangroves, salt pans, and rice paddies. Grasslands and open country provide habitat for soaring raptors and flocks of land birds. Coastal regions attract seabirds migrating via marine routes.
Major wintering sites for migratory birds in India
Some key wintering sites and wetlands used by migratory birds in India include:
- Keoladeo National Park, Rajasthan
- Sultanpur National Park, Haryana
- Point Calimere Wildlife Sanctuary, Tamil Nadu
- Chilika Lake, Odisha
- Nalsarovar Bird Sanctuary, Gujarat
- Harike Wetlands, Punjab
- Ranganathittu Bird Sanctuary, Karnataka
- Vembanad Lake, Kerala
- Thane Creek, Maharashtra
- Pong Dam Lake, Himachal Pradesh
The availability of water, food resources, and habitat make these sites critical for sheltering large concentrations of migratory waterfowl each winter. Inland lakes and reservoirs also provide important stopover points for migrating land birds and raptors.
How many species migrate to India each year?
According to eBird data, around 800-900 bird species have been recorded migrating to India during the winter months. The exact number fluctuates somewhat annually. Here is a breakdown by category:
- 250-300 wetland species (ducks, waders, gulls, terns)
- 150-200 raptor species (eagles, hawks, falcons)
- 250-300 land bird species (warblers, thrushes, buntings)
- 100-150 seabird species (pelicans, gannets, skuas)
So in total, India hosts between 800-900 migratory bird species every winter. The bulk of these migrants are wetland species that time their migrations to take advantage of India’s wetlands and monsoon-fed habitats. The most abundant winter visitors include ducks, waders, swallows, warblers, and raptors.
Top 10 most abundant migratory birds wintering in India
| Common Name | Scientific Name |
|---|---|
| Ruff | Calidris pugnax |
| Black-tailed Godwit | Limosa limosa |
| Northern Pintail | Anas acuta |
| Common Teal | Anas crecca |
| Eurasian Wigeon | Anas penelope |
| Northern Shoveler | Spatula clypeata |
| Garganey | Spatula querquedula |
| Common Sandpiper | Actitis hypoleucos |
| Barn Swallow | Hirundo rustica |
| Common Greenshank | Tringa nebularia |
These migratory waterbirds and shorebirds arrive in huge flocks to wetlands across the country starting in August. They stay until March or April before returning north to their breeding grounds.
Notable long-distance migrants to India
Some species, like waders and seabirds, make incredibly long migrations to reach India each year. Some of the most remarkable long-haul migrants include:
- Amur Falcon – Breeds in Siberia and northern China, winters in southern Africa, migrating through India in huge numbers.
- Pied Cuckoo – Breeds from Russia to western China, winters in South Africa, passing through India.
- Barn Swallow – Nests across the Northern Hemisphere, winters as far south as South Africa and Australia, via India.
- Common Crane – Breeds across Eurasia, winters in northern Africa and India.
- Demoiselle Crane – Breeds in central Asia, winters in India.
- Bar-tailed Godwit – Breeds in Alaska and eastern Siberia, winters in Australia, New Zealand and Southeast Asia, stopping in India.
- Sooty Shearwater – Breeds on islands off New Zealand, Chile, migrates north via India to the North Pacific for the boreal summer.
These marathon migrants travel thousands of kilometers between their Arctic breeding grounds and wintering areas in the Southern Hemisphere, relying on stopovers in India to rest and refuel. Their migrations are among the most incredible journeys in the animal kingdom.
Threats facing migratory birds in India
Migratory birds face a number of threats on their passages through India, including:
- Habitat loss due to wetland drainage and destruction
- Pollution, including oil spills that affect wetland birds
- Overfishing, which depletes food resources
- Climate change impacts on habitat
- Hunting and poaching
- Collision with wind turbines and transmission lines
Wetland birds are especially vulnerable when stopover habitats along their migration routes are degraded or disappear. Conservation of these critical ecosystems is crucial for sustaining migratory bird populations that depend on them.
Conservation efforts
A number of conservation initiatives aim to protect migratory birds in India:
- Designation of wetlands and coastal sites as protected areas
- Community conservation programs at key wetlands
- Monitoring and habitat management through coordinated networks like the Asian Waterbird Census
- Targeted conservation action for threatened migratory species
- Engaging local communities and raising awareness
- Implementation of international agreements like the Convention on Migratory Species (CMS)
Continued efforts to conserve wetlands and combat threats during migration are key to ensuring healthy bird populations. Community-based approaches to protect habitats and promote sustainable management have shown good results around major migrant hotspots in India.
Conclusion
India serves as a vital winter refuge for hundreds of migratory bird species that undertake remarkable journeys along the flyways of the Asia-Pacific region each year. The availability of diverse wetland habitats makes India a critical stopover destination for waterbirds migrating south from Central Asia to escape the northern winter. While exact numbers fluctuate, around 800-900 species of migratory birds across numerous families arrive in India between August and March annually before returning north. Conservation of wetlands and mitigation of threats during migration are crucial for maintaining these incredible avian migratory phenomena.
