Existing habitats will be gone unless the Yamuna basin is protected, says Asian Water Bird Census-2010
With the Asian Water Bird Census-2010 in Delhi revealing a marked fall in the arrival of migratory birds, the report of the State Coordinator Delhi for Wetlands International South Asia has cautioned that until the general public becomes aware about conservation and the Government takes immediate steps for protection of the Yamuna river basin, the existing habitats of water birds in Delhi will become completely degraded and get converted into dry lands in the near future.
The bird census was conducted at four sites across Delhi during the scheduled period between January 9 and January 24 by AWC Delhi State Coordinator with the help of a volunteer team.
State coordinator T.K. Roy said this year a number of factors affected the arrival of birds. “The winter was late and the arrival of migratory water birds was less both in number and species. Even otherwise the migration rate of water birds has been gradually declining in Delhi region during the last few years.''
Mr. Roy said while overall effects of global warming, climatic changes and degradation of habitats were the major reason behind declining rate of migration of water birds all over the world as per reports of the scientific organisations, in Delhi a number of local factors have also contributed to this worrying trend.
He said among the four Asian Water Bird Census sites in Delhi, the four square km area of Okhla Bird Sanctuary is the only major habitat in the heart of polluted Delhi that still attracts a large number of migratory water birds from diversified species during winter. However, he said, the census found an alarming drop in their numbers this year. Only 112 bar-headed geese came this year compared with 212 in 2009. Similarly the number of gadwal was down to 72 from 302; northern shoveler to 484 from 854; northern pintail 172 instead of 272; only 231 common coot were spotted in place of 355 in 2009; the mixed flock of brown-headed and black-headed gull dropped to 345 from 877 while the Eurasian widgeon came down to 15 from 18.
While the number of grey-leg geese remains almost the same at 411 instead of 416 in 2009, the number of Eurasian spoonbills increased to 16 from six. The only species which showed a marked increase in arrivals was the common teal which increased to 184 from 78 in 2009.
However, the number of common pochard fell drastically to 28 from 320 in 2009; while the tufted pochard also dropped to just four from 236 in 2009. The local resident species of greater flamingos this time suddenly disappeared during January and 20 were later tracked. The other species that gave Delhi a miss this time included avocet, bar-headed and black-tailed godwits, comb duck and garganey among others.
As for the local conditions which adversely impacted the arrival of these birds, Mr. Roy said the water level of the sanctuary was higher during winter and the smaller islands and marshlands remained almost submerged. Due to this most of the common wader species did not camp in Delhi this winter as they could not find suitable habitat to walk on water and feed.
Still some of the waders like wood sandpiper, green shank, spotted green shank, common Redshank, little stint and temminck's stint did arrive in small numbers to areas downstream of the Okhla Barrage.
On the western bank of the Yamuna, Mr. Roy said, while the sanctuary provides a much better habitat to the waders, as it has marshlands, the disturbance caused by the frequent movement of people and cattle kept them away.
“Almost the entire habitat for water birds along the stretch of the Yamuna in Delhi region is badly degrading (except upstream of Wazirabad and Okhla barrage) due to winter cultivation on the river bed and islands and extreme water pollution due to direct flow of industrial and domestic sewage, through canals and drains, into the river. Dumping of non-biodegradable waste into the river and rapid development works pertaining to construction of roads and bridges for the upcoming Commonwealth Games are all affecting the arrival of birds,'' he said.
Though following the census, many of migratory species like northern shoveler, northern pintail, common coot, common teal, gadwal, brown-headed and black-headed gulls and Eurasian spoonbill came to the sanctuary, he said, this was primarily de-migration as the temperatures went up sharply in the early part of February.