Point counts method for bird surveys in agroecosystems of the state of São Paulo, Southeastern Brazil

Abstract

The point counts method has been developed for, and extensively used in, forest habitats for bird surveys. Although the method has already been applied to anthropic habitats, its efficacy has never been tested in such circumstance. The main goal of this study was to test this method in different agricultural habitats. We surveyed birds in 16 study sites of the following types of habitat of Passa-Cinco river basin (between latitudes 22°05′ and 22°30′S, and longitudes 47°30′ and 47°50′W) in the state of São Paulo, Southeastern Brazil, from September 2003 to January 2005: native forest fragments, Eucalyptus and sugarcane plantations, and exotic pastures. We compared the efficacy of four distinct kinds of bird detection (auditory, visual, auditory followed by visual, and visual followed by auditory) in relation to the habitats. Visual and auditory detection were proportional and compensatory considering all habitats surveyed. The results suggest that point counts can be efficiently used for bird surveys in local agroecosystems, where the habitats variability allows the balance between visual and auditory detections.