Come winter, come winged guests.

The sudden Celsius slump has brought birds of many feathers flocking to lakes and reservoirs of Ranchi, much to the delight and relief of ornithologists and conservationists.

If the picturesque Patratu Dam was teeming with waterfowls like the ruddy shelduck ( Tadorna ferruginea) - also known as the Brahminy shelduck in India - last Thursday, birders to Kanke Dam on Sunday claimed to have spotted the tufted duck (Aythya fuligula). If the Brahminy shelduck has distinct bright orange plumage and pale head, the tufted duck is easily identifiable by its black head tuft and diving skills.

"Better late than never," Samir Sinha (30), an adman with a fetish for every feathered thing, heaved a sigh of satisfaction. "Every winter Sunday, I tour lakes and dams to catch glimpses of migratory birds. It is my favourite pastime. I had almost given up hope this season when nature sprung a pleasant surprise," he said.

Ranchi DFO (wildlife) Kamlesh Pandey, himself an avid bird watcher, said he was on a clicking spree at Hatia and Kanke dams for the past 10 days.

"The ruddy shelduck and the tufted pochard or the tufted duck are some of our winter guests. The tufted duck is mostly found in reservoirs of Andhra Pradesh, Tamil Nadu and Karnataka, and also countries like Pakistan, Sri Lanka and Maldives. The ruddy shelduck, on the other hand, is a native of Mongolia and western China," Pandey said on Monday.

While the DFO (wildlife) said they were yet to begin a formal headcount of species, birders at Patratu claimed they had seen a dozen species already, including the white-necked stork and the whistling duck.

In the winter of 2014, the forest department had sponsored the first-ever avian census in Jharkhand. The Asian Water Bird Census (2015) was conducted across 25 water bodies and collated data had revealed a migratory guest list of 71,134 birds who had flown in to the state from both within and outside the country.

Satya Prakash, state coordinator for Indian Bird Conservation Network, is sanguine that this year will be more positive. "We are gearing up for another month-long census in January. Last year, as many as 11 threatened species were recorded in Jharkhand, including the darter or snakebirds. Among the total 78 species recorded, the fascinating oriental white ibis and Eurasian curlew were also found," he said.

A forest official, not willing to be named, citied encroachment and pollution of water bodies, besides poaching, as major deterrents for migratory birds, which he said flocked in larger numbers earlier.

Ranchi DFO Rajiv Lochan Bakshi didn't answer calls on Monday. One of his deputies, however, said that every year flying squads were mooted to guard prominent reservoirs, but the plan never implemented for some reason or the other.