A comparison of point counts and sound recording as bird survey methods inAmazonian southeast Peru

We tested the ability of sound recordings relative to that of point counts to estimate species richness in the Tambopata Reserve in southeast Peru. We tested the effect of two environmental factors (estimated richness and pre sence of noisy species) and two attributes of species (abundance and foragi ng height) on estimates of species richness made by point counts and sound recordings. Sound recordings are preferred to point counts when richness is high, as during the dawn chorus, because they allow for repeated listening s. Point counts are more effective than sound recordings at detecting rarel y heard species. The presence of noisy species at a station had no effect o n the relative ability of the two methods to measure species richness. The foraging height of a species had no effect on its relative detectability by either method. Sound recording was found to be a suitable alternative to p oint counts for estimating species richness and a preferable alternative un der some circumstances.