Over 50,000 migratory birds have arrived at the Maharana Pratap Sagar Lake, also known as the Pong Reservoir, in Himachal Pradesh's Kangra district, officials said on Friday.

The general counting of the birds is being done every fortnight. The annual counting will be done on January 29 and January 30, when it is believed that the highest number of migratory birds are at the lake, Assistant Conservator of Forest in Dharamshala Pardeep Thakur said.

The lake was created in 1975 by building the highest earthfill dam — Pong Dam — in India on the Beas River in the wetland zone of the Siwalik Hills in the district.

Thakur said around 55,000 migratory birds have already arrived since October.

 The lake is a well-known wildlife sanctuary and one of the 27 international wetland sites declared in India by the Ramsar Convention.

"The birds start arriving here in October and start their return journey in April. Most of the birds are from Siberia, Central Asia and Russia. There are hundreds of avian species but the Bar Headed geese are in abundance here," he said.

"We have appointed an adequate number of staffers for the protection of these migratory birds. The anti-poachers team is assisting forest guards," Thakur said.

He said that according to Supreme Court guidelines, special staff has been appointed to check illegal cultivation around the lake. "We have also installed CCTV cameras in our main Sukhnada campus," Thakur said. 

The lake covers an area of 24,529 hectares and the wetlands portion is 15,662 hectares.

The number of birds at the lake last year was 1.10 lakh compared to 1.27 lakh in 2017 -18.

Thakur said, "We have more birds in the years when water of the lake recedes and there is more dry land for the visiting birds."