According to veteran ornithologist Hem Sagar Baral, both global warming and rapid reduction of trees and wetlands are reasons behind the lesser numbers of birds and bird species coming to Nepal to stay during summer and winter. [break]
“Since there has been no proper study, it may not be good to pinpoint climate change as the reason behind the decline. But I think it may be one of the reasons. Another thing obviously is the rapid and unplanned urbanization and loss of trees and wetlands, which have quite affected the birds´ habitat,” said Baral, who is also an adjunct senior lecturer at the School of Environmental Sciences at Charles Sturt University in Australia and country manager of the Conservation Program in Nepal overseen by the Zoological Society of London.
Baral and another bird expert, Suchit Basnet, both of whom have been active in bird counting in Nepal since a long time back, estimate that the decline in numbers could be fixed at around 20 percent.
“There has not exactly been a gradual loss if we look at every year´s graph. However, compared to 10 or 15 years ago, we can assess that the numbers are lesser by around 20 percent,” said Baral.
Supported by Wetlands International, bird counting in the country is done every January, with the engagement of around 200 technicians.
Bird species including ducks, eagles and falcons come all the way from Siberia, Mongolia, China and Eastern Europe and settle in different parts of Nepal for around six months in winter. Some even transit Nepal and fly further on, the experts said.
Over 150 species of birds arrive in Nepal in summer and around 60 species in winter. These numbers were higher in the past, Baral and Basnet believe.
“The migratory birds we receive here are basically those who survive in wetlands. Records have shown that the wetlands are gradually shrinking. They are also getting drier,” Basnet said. “As a result, both summer and winter migratory birds that come here are being affected. No less affected are the residential ones,” he added.
A paper recently released by the Department of National Parks and Wildlife Conservation sheds light on the deteriorating status of residential birds, which ultimatley reflects the situation of migratory ones as well.
The study states that in 2010, 149 bird species in Nepal (17 percent of the total recorded) were considered nationally threatened: 53 critically endangered species, 48 endangered and 47 vulnerable. An additional 16 species were considered threatened in 2010 compared with 2004. No species assessed as threatened in 2004 was considered non-threatened in 2010. When habitat types are considered, wetland species are the most threatened (35 percent of the total wetland species), followed by grassland species (23 percent). When altitudinal preferences are considered, lowland species are the most threatened (36 percent of all lowland species), followed by species only occurring in the middle hills (17 percent).
According to Baral, the migratory birds travel around 4,000 to 5,000 miles to reach Nepal. While the non-stop travelers cover the long journey within just two days, others take around 10 days.
Jyotendra Thakuri, conservation officer at Bird Conservation Nepal (BCN), added that the birds come here via Kaligandaki Valley in the west and the Arun Valley in the east.
“The winter birds who start coming here around October do so in search of a warmer climate, and the summer visitors come for some chill. The days are short in winter in the northern latitudes, which gives birds less time to search for food. So they come over here. Similarly, some of the migratory birds go to Southeast Asia through our country,” Thakuri said.
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