Birds: A bio-control agent in farmland ecosystem

Abstract

Paddy-field ecosystem is an important habitat for birds. Birds are influenced by several factors and among them habitat heterogeneity is the most important. This study aimed to know role of avifauna in paddy-field ecosystem. Birds were surveyed in three different habitat heterogeneity classes (zero, moderate and high tree density) in three different time slots (morning, afternoon and evening) by using point count method. An imaginary plot having a radius of 60 m (equivalent to nearly 1 ha circular plot) was taken from the centre of the field. A total of 2493 individual birds were recorded. These belonged to 71 species of 31 families. Bird species richness (31 < 43 < 57) and abundance (480 < 785  <  1228) increased from Zero tree density class to High tree density class. Among species, 21 were omnivorous, 21 insectivorous, 12 granivorous, 15 carnivorous, and 2 nectarivorous. Thirty six bird species were categorized to be beneficial (i.e. insectivorous and carnivorous) and were found to be abundant in plots with trees. We contend that this kind of baseline data will be useful to increase the habitat heterogeneity on farmland and to initiate integrated pest management (IPM) experiments involving birds and other vertebrates, and also to assess the efficiency of organic farms to support birds and obtain their services.