A Comparison of Transects and Point Counts in Oak-Pine Woodlands of California

Abstract

Transects and point counts were compared as methods for measuring species richness, relative abundance, and density of birds in oak-pine woodlands of central California [USA]. Efficiency of the 2 methods for measuring species richness or giving total counts varied with study design and season. Point counts are recommended over transects for most studies in which results of these methods are suitable. Frequency is a measure of relative abundance that should be used only with due caution for its limitations. Density estimates are probably superior to total counts for indexing relative abundance but they are limited because the small sample sizes attained in most studies permit density estimation for only a small percentage of the species detected, and available evidence challenges assumptions that density estimates by transects or point counts are acceptably accurate.