Bats of Alagoa Grande, a semi-arid area of Northeastern Brazil

Abstract

Bat fauna is surveyed mainly by mist-nets set in the ground level, and usually employing six hours per night of capture comprising the first peak of activity to most bat groups. Bat inventories with whole-night sampling effort (12 hours) have not been conducted so far in the northeastern of Brazil. This paper aims to report a whole-night survey of the bat assemblage from Alagoa Grande, a Caatinga site in the state of Paraíba, northeastern Brazil. Additionally, we compared the species richness and abundance between the two halves of the night, from dusk (5h p.m.) to 11h p.m., and 11h p.m. to dawn (5h a.m.). We conducted 15 nights of sampling from September/2010 to January/2011, sampling three nights per month. A total of 56 individuals belonging to 12 species were captured, with Rhynchonycteris naso and Artibeus planirostris being the most abundant species. The Chao1 richness estimator predicted an average estimated richness of 18 species. There was no significant difference in the species richness between the first and the second halves of the night. However, the second half presented a higher overall abundance and three species were exclusive to each half. Our data highlighted the importance of whole-night samplings, mainly in short surveys.

Keywords: whole-night sampling, Caatinga, Chiroptera, diversity, Rhynchonycteris naso.