The present investigation was carried out during January and February 2002 on 88 irrigation tanks. These 88 tanks were chosen out of the 433 tanks surveyed 10 years ago in the Tiruvannamalai district. The objective of the study was to   ascertain the likely changes in bird population and threats. The various parameters like water level, encroachment, siltation, social forestry activity, infestation by weeds, submerged vegetation, agricultural practices carried out, nature of water surface, colour of water, hunting and trapping of birds and socioeconomic status of the people were investigated.   Altogether 212,227 birds belonging to 69 species were recorded.   The density of birds, which was 28.51 birds/ha during the erstwhile study has marginally dropped to 25.04 birds/ha during the present investigation. In the present study only 25 tanks became full and the quantum of water received by other tanks varied widely. Almost all the tanks suffer from siltation and encroachment. In 56% of the tanks, which were brought under social forestry activity, the area covered ranged from 10 to 75%. 70% of the tanks that suffered   weed infestation during the previous investigation has increased by 13% now and the extent of infestation ranged from 10 to 100%. Except 10 tanks, which had sparse submerged vegetation, all other tanks had moderate growth. The hunting and trapping of birds, which took place in 15% of the tanks during the previous study has increased by 5% over the years.

Secretary,
Society for Environmental Education and Conservation,
2/71, 5 th Cross, Kanakasabai Nagar,
Chidambaram – 608 00.
Tamil Nadu. India.
Email: sampmul@yahoo.co.in