Ravaged river Yamuna, flowing for nearly 22 kms through Delhi, has seen a mixed bag on its wetlands as regards arrival of water birds this year.  While some species of migratory water birds in lesser number arrived, the wetlands managed to attract maximum number of Gulls.

Gulls continuously cannot stay longer on the most degraded, polluted riverine habitat and keep moving in search of food, roosting and attracted to the banks of Yamuna where public throws food to them for feeding, according to Asian Waterbird Census(AWC)Delhi state coordinator and ecologist T K Roy said here on Thursday.

He said Wetlands International's annual Asian Waterbird Census (AWC) part of the global International Waterbird Census is carried out in the month of January in 27 countries together in Asia and Australasia.  Indian volunteers participate in it under coordination of the AWC State Coordinators as per the confirmed annual dates by National Coordinator. AWC supports the conservation and management of wetlands and water birds globally.

Serious birders and volunteers on Wednesday participated in AWC 2025 at River Yamuna in Delhi (Wazirabad Barrage to Nizamuddin Bridge), he said.

AWC supports conservation of wetland and water birds globally and it is an important tool generates the data for the Ministry of Environment, Forest and Climate Change (MoEFCC), Govt of India's "National Action Plan for conservation of Migratory Birds & their habitats along the Central Asian Flyway".

He said due to global climate change impact, delayed monsoon and winter migratory winter water birds arrival delayed lesser species in lesser number on several wetlands includes River Yamuna in Delhi. Still some species of migratory water birds in lesser number arrived and maximum number of Gulls.

During AWC 2025 recorded partially increased water bird species diversity i.e. 25 species of total population 2,123 includes 16 resident species and 09 migratory species in comparison to AWC 2024 i.e. 22 species of total population 2,037 includes 08 resident species and 14 migratory species.

In 2025, among 09 migratory species include largely Black-headed Gulls 1,636 and among 16 resident species largely Black-winged Stilts 110, Little Cormorant 104, Indian Cormorants 53 in comparison to last year (2024) 14 migratory species largely Black-headed Gulls 1,646, Great Cormorant 81 and among 08 resident species largely Black-winged Stilt 198.

Among the migratory duck species recorded only Ruddy Shelduk 06 instead of 16 Common Teal last year, Pallas's Gull 09 instead of 01 last year and resident birds Grey Heron 59 than 24 last year and IUCN Red-listed Near Threatened (NT) resident species River Lapwing 09 recorded in 2025 than last year 03 and Painted Stork 14 this year than no record last year.

On River Yamuna last four years, AWC recorded variable species diversity in numbers.  Among these resident species either decreased or increased in number recorded as follows:

• Black-winged Stilt decreased, Red-wattled lapwing increased
• Grey Heron increased, Indian Spot-billed Duck decreased
• Little Cormorant increased, River Lapwing increased
• Among the winter migratory species, Great Cormorant from East and Southeast Asia increased. Brown-headed Gull migrating from Central Asia decreased,
• Black-headed Gull migrates from Central Asia and Siberia increased and Pallas's Gull migrates from Central Asia partially increased.

— Writer is an Ecologist, Ornithologist and State Coordinator at AWC Delhi State Coordinator; Wetlands International South Asia)