India, Dec. 22 -- Birdwatchers in the national Capital are a disappointed lot as winter migratory birds are not expected to flock in large numbers to the polluted River Yamuna next month.

The river traverses nearly 22 km through NCT-Delhi. Earlier, the Yamuna was very clean and undisturbed, attracting a wide and diverse species of birds. However, the situation is not favourable now due to the polluted river and making wetlands unsuitable for birds.

Moreover, global climate changes like late monsoon and delayed winter have impacted the arrival of resident water birds and long-distance winter migratory birds. Earlier, birds used to be here in November and December, according to TK Roy, Ecologist, Ornithologist, AWC State Coordinator, Delh...