Analysis of Avian Diversity at Chintamoni Kar Bird Sanctuary: An Urban Forest Perspective

Chintamoni Kar Bird Sanctuary (CKBS) is an urban forest located on the southern fringes of Kolkata. The objective of our study was to document and analyze the diversity of the avian population in CKBS. The line transect method was used and avian diversity, species richness and evenness were analyzed using Shannon Diversity Index, Shannon Equitability Index, relative diversity and relative abundance. Our study recorded 37 bird species belonging to 9 orders and 23 families with most species being recorded from Order Passeriformes followed by Piciformes and Ciconiiformes. The species were well distributed across a number of avian families. Birds rare in metropolises like the Oriental white eye (Zosterops palpebrosus) were also recorded here. Analysis of relative abundances showed that many species comparatively rare in cities like the common tailor bird (Orthotomus sutorius) and white throated fantail (Rhipidura albicollis) showed an abundance similar to more commonly seen species. Values of 2.844 and 0.788 were obtained for Shannon Diversity Index and Shannon Equitability Index indicating high species diversity and evenness. However, high species diversity is not due to assemblage of migratory birds in winter. Species diversity and evenness are highest during the summer months (Shannon Diversity Index = 2.862; Shannon Equitability Index = 0.812) which could be due to dense forest cover, a large number of fruit bearing trees and many water bodies in the sanctuary which provide a favourable habitat for birds in hot weather. Our study indicates that a number of birds appear to be thriving as a stable avian community at CKBS and this urban forest acts as a haven for bird species otherwise rare in Kolkata, further emphasizing the need for taking necessary conservation measures for protection for this urban forest under the strained environmental conditions prevalent in urban metropolises.