Acoustic surveys of birds using electronic recordings: new potential from an omnidirectional microphone system

TLDR

Conventional acoustic surveys of avian communities require expert skills that are rare, especially during the brief singing periods of most temperate North American species. We investigated the use of two newly developed omnidirectional microphones for field recordings of forest bird communities. Our study compared species richness and abundance recorded by field experts with those inferred from simultaneous recordings analyzed by the same observers using the microphones. The technique performed well in southern boreal mixedwoods, yielding 83–97% similarity for presence–absence and abundance data, and offers advantages such as archived records, use of non‑expert staff, and standardized data collection.

Abstract

Conventional acoustic surveys of avian communities require expert skills that are rare, particularly during the relatively short singing periods of most temperate North American species. We investigated the use of 2 newlydeveloped omnidirectional microphones for field recordings of forest bird communities. Our study compared richness and abundance of species recorded by field experts and those inferred from simultaneous recordings later analyzed by the same observers. The acoustic recording technique worked well for bird communities associated with the southern boreal mixedwoods of central Saskatchewan and western Ontario. Similarity measures for both presence-absence and abundance data ranged from 83 to 97%. The acoustic recording technique, particularly in a stereo configuration, could be used to analyze species composition and relative abundance of forest bird communities. Moreover, this approach had numerous advantages, including an archived record of point counts, the use of non-expert field staff to collect recordings, and the standardization of field data through time.