An assessment of indices of relative and absolute abundance for monitoring populations of small mammals

Abstract

Abstract Knowledge of small-mammal population densities and species richness values are crucial to wildlife conservation and many ecological investigations. The relationship between estimates of absolute abundance and relative abundances of small-mammal populations is unclear. Therefore, from 1999–2001 measures of relative and absolute abundance of small mammals were compared across a terrestrial landscape using 3 vegetation communities (forest, early-successional field, and forest-field edge) in western Tennessee. We used a catch/unit effort index derived from transect sampling to estimate relative abundance and 2 estimates of absolute abundance, Mt+1 (the number of unique individuals captured) and Nest (a population estimate obtained from statistical models). These 2 estimates were derived from mark-recapture sampling on trapping grids. Using both sampling procedures, we conducted trapping with Sherman live traps during autumn, winter, and spring for 2 years. We tested the prediction that the pattern of...