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Chairman: Dr. Rakesh Kumar & Dr. S. Balasubramanyam |
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Aquatic
and terrestrial conditions combine to form 'wet-lands', one among the most
complex ecosystems in the world. The environmental characteristics within a
wetland are determined largely by hydrologic processes, which may exhibit daily,
seasonal or long-term fluctuations, in relation to regional climate and
geographic location of the site. These in turn produce a great range of wetland
types globally, majority of which have extremely variable conditions in many
habitats, which they contain. As a consequence, the variety of living organisms,
adapted to the different wetland habitats tends to be high, with all major
groups of plants and animals present. The Convention on Biological Diversity's
Article 7 on 'Identification and Monitoring' emphasizes identification and
monitoring of components of biological diversity and processes or categories of
activities, which have adverse impacts on biological diversity, and maintenance
of data derived from these activities.
The
bird diversity study was taken up in the Sharavathi River basin, prone to
habitat transformation due to dam construction for hydro-electricity generation.
As part of the cumulative impact assessment exercise, a detailed study was
undertaken to determine the habitat status. This paper brings out the study on
bird diversity estimation in the catchment area. The data collection was done
using the line transect method in nine localities of the study area. The
localities are classified chiefly as wetlands and terrestrial habitats. Other
statistical analyses carried out on the data are presented in the paper.
The
study was successful in estimating the diversity index using the Shannon's index
as well in finding the evenness of the habitat. An important observation made by
the study was that the order Passeriformes dominated the terrestrial habitat.
The study also revealed that the wetlands had a better distribution of birds.
This could be inferred from the fact that unlike the terrestrial habitat,
Passeriformes and Ciconiiformes dominated wetlands, suggesting that these
ecosystems have more diversity than terrestrial habitats. During the sampling
period, 73 species were identified but a total of 125 species were sighted
including opportunistic surveys. Of
the 125 species four are endemics and one endangered species; which is
threatened for their survival in the region. In the wake of infrastructure
development initiatives in the region the endangered bird species mostly found
in the undisturbed evergreen forests is threatened by the loss of habitat.
Effective conservation strategies in ensuring the continued survival of the
endemic and endangered bird species through ecologically sound development
initiatives are to be evolved in this regard. The paper explores the possibility
of using bird diversity as an indicator of ecological status.
Address:
Energy and Wetlands Research Group,Centre for Ecological Sciences
Indian Institute of Science, Bangalore-12, India
Phone: 080- 3600985 / 3092506
Fax: 91-80-3601428 / 3600085 /3600683{CES-TVR}
Email: cestvr@ces.iisc.ernet.in,
cestvr@hamsadvani.serc.iisc.ernet.in
hssudhira@yahoo.com