Three methods for assessing richness and composition of small mammal communities

Abstract

Analysis of pellets of Tyto alba and scats of Genetta genetta and Sherman livetrapping were compared to assess richness and composition of small mammal communities in a Mediterranean area (NE Spain). Owl pellets provided 17 small mammal species (17,232 individuals), genet scats 14 species (2,145 individuals), and livetrapping 9 species (1,488 individuals). Owl pellets oversampled insectivores and grassland rodents and undersampled tree-dwelling and woodland rodents. Genet scats and livetrapping oversampled woodland rodents and undersampled insectivores and grassland rodents. After controlling for sample size and elevation differences between methods by means of analysis of covariance (ANCOVA) and rarefaction, owl pellets contained higher richness for small samples (<50 individuals), and scats contained higher richness for large samples (>100 individuals), both having higher richness than livetrapping regardless of sample size. We concluded that both indirect methods provided complementary information of small mammal communities, detecting the 19 small mammal species known to be present in the study area.