By Binu Shrestha Kathmandu, Jan. 21: The number of migratory water birds at Taudaha Lake has been on the decline since last few years. However, dramatic fall in their numbers last year has raised the eyebrows of bird enthusiasts and conservationists alike. That fact came to light when Bird Conservation Nepal (BCN), under the winter water bird census that began on January 2, counted the number of water birds at Taudaha on January 16. The annual nationwide census was held to determine the number of water birds, condition of their habitats and their present status, said Vimal Thapa, general secretary of BCN. The census found that the water birds have steadily become endangered due to the different anthropogenic activities in the area surrounding the lake. Construction activities like fast track corridor, Chobhar Dry Port and other Taudaha beautification projects have played major roles in jeopardising their existence. In addition, the BCN was able to count 20 species of water birds among a total of 72 species of birds that inhabit the area. The staff members of BCN, volunteers, researchers, student and the locals participated in the bird counting programme, which covered the area from Chobhar-based Jal Binayak Temple to the Bagmati River and Taudaha Lake. Two species -- Northern Shovler and Ferrugineous Pochard -- were recorded in the months of November and December. Previously sighted birds like Common Pochard, Indian Spot-Billed Duck, Northern Shoveler and Ruddy Shelduck were not spotted this year. Common Teal, Gadwall, Pond Heron, Cattle Egreat, Grey-headed Lapwing, Common Sandpiper, Green Sandpiper and White Wagtail are among the species that were counted, Thapa said. Taudaha is also the destination of migratory birds, which arrive from North-Asia, including Tibet, China, Korea, Mongolia, Siberia and central Asia in winter season to the Kathmandu Valley to escape freezing cold there. But the human encroachment into their habitat has put them under threat, which is why their numbers are dwindling every year. The census also counted birds in more than 60 wetlands, lakes and rivers at 14 different locations across the nation. Nepal has witnessed 150 different species of winter migratory bird species arriving from abroad. They come to the various wetlands of the country -- Koshi Tappu, Bishajari Lake, Jagdishpur Lake, Ghodaghodi Lake, Shuklaphanta, Koshi and Gandaki rivers, among others -- to escape the biting cold in their home countries. Nepal has a record of 9 per cent of the total bird species found worldwide. The county has 886 species of birds. Of these, 42 are globally endangered.