The
present investigation was carried out during January and February 2002 on 88
irrigation tanks out of the 433 tanks surveyed 10 years ago in the tiruvanamalai
district with the objectives of ascertaining the likely changes in bird
population and threats. All the birds encountered were enumerated by walking
over the bund around the tank. 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. Alltogether 212,227 birds belonging to 69
species were recorded. The density of birds which was 28.51 birds during the
erstwhile study has marginally dropped to 25.04 birds during the present
investigation. In the present study only 25 tanks became full this year and
quantum of water received by other tanks varied widely. Almost all the tanks
suffer from siltation and encroachment. In the 56% of the tanks which were
brought under social forestry activiy, the area covered ranged from 10 to 75%.
The record of 70% of tanks suffered from infestation during the previous
investigation has increased by 13% now and the extent of infestation ranged from
10 to 100%. Except 10 tanks, which possessed sparse submerged vegetation all
other tanks had moderate growth. The hundting and trapping of birds, which took
place in 15% of the tanks during the previous study has increased by 5% over the
years.
Address:
Society for Environmental Education and Conservation
2/71, 5th Cross, Kanakasabai Nagar
Chidambaram – 608 001. Tamil Nadu, India
E-mail: sampmul@yahoo.co.in
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