As per the Rohilkhand Nature Club, every year around 60 species of the winter birds are spotted in several wetlands of Bareilly district. Out 60 species of winter birds that flock here, 12 are varieties of migratory ducks. These ducks start arriving from Central Asia in November and usually return home by the end of March. "However, we have spotted only six species of migratory ducks, while species, including Eurasian Wigeon, Bar Headed Goose, Ferruginous Pochard and Garganey have not arrived yet. As January has started, there are less chances that these migratory species will come here," said KaajalDasgupta, secretary of Rohilkhand Nature Club. He added that this year, the migratory birds are less both in numbers and species in Bareilly by nearly 50% in comparison to last year.

According to bird watchers, out of total 1,501 wetlands in the district, the migratory birds used to prefer many wetlands in and around the city. However, this winter, a large number of birds have been spotted only at three ponds, situated near Lal Phatak and in Akha village and IFFCO factory in Aonla. "Due to the drought last year, many wetlands have dried up. The city has now been receiving less rainfall unlike previous years. This is the reason that the pond in Hazratpur village which is nearly 15 km away from the city has dried up," said Dasgupta.

He added that river pollution, climate changes and global warming main reasons behind lesser number of birds arriving in Bareilly this season. "As the winters are becoming warmer, migratory birds are opting for other spots rather than staying in Bareilly," said Dasgupta.

TOI had earlier reported that a report of Uttar Pradesh Pollution Control Board submitted in National Green Tribunal had stated that many toxic substances are found in Ramganga.

Among the migratory birds that have been sighted this season are Northern Pintail, Northern Shoveler, Common Pochard and Gadwall.