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Avifauna in two different residential localities of Kolkata viz. Cossipore of North Kolkata and Dhakuria of South Kolkata was done in twelve months period from December, 2013 – November, 2014 to get some idea about the present avian diversity of the city. Total forty eight species of birds belonging to twenty five families were identified from the two sites and recorded along with their abundance in this study. Fluctuations in abundance of bird fauna between the study areas were also recorded which may be attributed to the loss of proper habitat for foraging and nesting due to continuous urbanization and increased pollution rates.
We assessed the assemblages of birds inhabiting pine-dominated managed forest, aged between 1–5 years and above 140 years. Birds were counted on study plots representing eight different phases to the forest's development, with nesting, foraging and migratory guild categories recognised. Numbers of bird species and population densities, both increased markedly with stand age (respectively r = 0.988 and r = 0.936, P < 0.001). While numbers of ground-nesting bird species failed to correlate with stand age, successively older stands did support ever-greater proportions of species in the assemblage that nested in tree crowns (r = 0.976, P < 0.005) or tree holes (r = 0.833, P < 0.005). Raptors were most abundant in forest at the oldest stages of growth, and there was an age-gradient-related increase in the shares of both plant-eating species (r = 0.952, P < 0.005) and raptors (r = 0.764, P < 0.005). Resident birds were most numerous in the oldest forest. PCA for ten selected variables (relating to guild type) showed that the two principal components explained almost 98% of the variation among groups of bird guilds in relation to forest age. On the basis of their suitability for birds it was possible to distinguish three categories of stand by age group, of which the first encompasses the initial stage, the second a broad interval involving middle-aged stands of between 16 and 140 years, and the third forest more than 140 years old. The presence of the oldest stands of all can thus be seen to play a very important role in maintaining high-diversity populations of birds in managed forest.
The study is based on the avian community observed in the region. In total, 524 individuals, 27 genera and 35 species of birds belonging to 21 families have been recorded. Among them, the family Charadriidae with 15.08% incidence is the most frequent; immediately followed by the family Scolopacidae (11.26% of occurence). The highest observed species richness has been observed in case of the family Ardeidae. Little Ringed Plover (Charadrius dubius) is the most abundant avian species observed. The community consists of 40% Resident; 40% Resident-migrant and 20% Migrant bird species. It was observed that the concerned community shows a considerable diversity and a corresponding low value of dominance. In the feeding guild analysis, the Insectivore and the Aquatic invertebrate-feeder guilds have the most number of recorded avian species. The feeding guild affiliations also points out that the overall community is fairly rich in its composition as it houses bird species belonging to various feeding guilds.
The trees of parks and gardens support many species, the survival of urban-dwelling species mainly bird species. Birds amongst other species provide a wide range of environmental and social functions to cities and urban dwellers. The present study aims to know bird diversity in two parks as bioindicator of automobile air pollution exposure, landscape changes and/or human interactions. The study areas were selected as per heavily-populated neighborhoods, nearby office buildings, nearby roads and continuous vehicular movements, human interactions as visitors, where high levels of human disturbance are common. The study was carried out at 2 sampling stations viz (i) Elliot park and (ii) Agri-horticulture Society. The bird species diversity was studied by qualitative and quantitative assessment. Indices were Species richness, Index of Dominance, Relative abundance, Shannon-Wiener Diversity Index and Evenness Index for birds for all selected sites were calculated using the statistical formulae. The present results as bioindicators bird species clearly indicate that the bird species are very few in numbers in both the parks. When comparison made between both the parks, it was observed less number of bird varieties (16 types) in Elliot park than varieties (9 types) more less in number in Agri-horticulture society. This study is a preliminary assessment of bird diversity but further researches are needed in relation to biochemical and genetic damage study as well as air pollution load by using instruments. In the present study it was concluded that the less numbers of birds and their different diversity indices were found a decreasing trends, though there no attempt has been made on physico-chemical properties of present air pollutants. The less number of varieties of bird species are as tolerant bioindicators, which may be due to the vehicular pollution and/or human interference and/or landscape changes due to nearby neighborhood blocks, office and residential buildings, continuous movement of vehicles etc.
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