Birdwatchers in Delhi are chirping with delight at the rare sight of an oriental darter nesting colony at the Okhla Sanctuary, the first time the bird has built a colony in this part of Asia, say experts.
"It has never happened before. So far, 14 of these birds have been seen at the sanctuary," said ecologist TK Roy. "While there is a decline in bird diversity and population, spotting of threatened bird species is a pleasant surprise."
The 400-hectare sanctuary on the Delhi-Noida border has a large lake - created by the construction of a barrage over the Yamuna river - which serves as a bird habitat, with 330 species recorded so far.
The darter presents a fascinating sight when it spears a fish and tosses it in the air before swallowing it. The bird, one among 173 listed by the International Union for Conservation of Nature as threatened bird species in the Indian sub-continent, is also one of two existing darter species in Asia.
"We need a focussed approach for conservation because such species have limited population," said a sanctuary official. Release of excess water from the Yamuna barrage dries up the habitat, affecting the survival of ducks and other wading birds.
The Asian Waterbird Census 2014 saw the number of birds spotted at the Okhla Sanctuary rise to 7,659 this year from 5,545 in 2013, but the number of species declined to 58 from 63 during the same period. Migratory bird species fell to 28 from 38 last year.
Garhi Mandu, Asola Bhatti Wildlife Sanctuary and Sultanpur National Park and Najafgarh Drain are other bird-watching spots in and around the capital, but due to climate change, human interference and pollution, fewer birds are spotted in these parts.