Avian Diversity of Vellayani Lake in Thiruvananthapuram District, Kerala, South India

Abstract

The study was focused on the avifauna of Vellayani Lake which is the largest fresh water lake in Thiruvananthapuram district, Kerala. The diversity and various components of bird fauna were studied from October 2017 to March 2018. Direct observation and the Total count method were employed to conduct the census of the birds. Weekly counts were noted accurately and 24 species of birds belonging to 16 families were recorded. Statistical tools, tables and figures were used for calculating the Simpson diversity index, abundance and frequency. The Grey headed swamp hen is the most abundant bird (0.3364) present in Vellayani lake with a lowest Simpson index rate (D) of 0.8869. Asian open bill has the least abundance value (0.0003). Barn swallow was the only one migrant bird, which was recorded from the study area. This wetland ecosystem is highly polluted due to the agricultural practices and encroachment.