Locals said the new birds are little bigger than the Siberian cranes and have black feathers and coniferous peaks.[break]
As of Thursday, the number of new winged visitors has reached over 500, locals said.
Environmentalist Murari Dhungana said the new birds were seen for the first time on Thursday and they might be a new species of Siberian bird.
Since the new birds do not have enough fur in their feathers, they could be from Siberia or any other cold regions, he said.
Every year Siberian birds start arriving in southern Nepal around mid-April and live here for around six months.
New species of bird found in Nepal