Traps, Mist Nets, and Observation for Avian Population Studies: A Comparison of Methods

Abstract

Birds, with their mobility and secretive habits, create problems for field biologists attempting to measure an avian population. There is variation in the conspicuousness of different species and in their susceptibility to capture. Avian population studies are further complicated by the changing activities of birds with the seasons, especially migration. Most attempts to study bird communities utilize either capture by traps or mist nets, or observation census methods. The present study was designed to use all three basic techniques through four seasons in an effort to compare their efficiencies in measuring avian abundance and diversity. Mist nets, funnel and potter traps were operated in a small woodlot near Ettrick, Wisconsin, and an observation route was established in the vicinity. The research was conducted for 172 days between March, 1977 and May, 1979, during which 742 birds were caught a total of 1074 times and more than 13,000 birds were counted along the observation route. A total of 110 species were observed and/or captured.