Site fidelity and other attributes of infrequently trapped bats over two decades in a montane wet sclerophyll forest

Abstract

A long-term perspective on bat populations is lacking in most ecosystems. We describe fluctuations in capture rate, sex ratio, body condition, site fidelity and longevity of banded bats over two decades as part of an annual banding study in a montane forest. We focus on five species previously omitted from mark–recapture analyses because band returns were too low. Each species was infrequently trapped and/or retrapped, though this was often highly variable. A degree of site fidelity was recorded for all species, even those where trap success was low. We recorded maximum longevity (likely an underestimate) of at least 5 years for eastern falsistrelle Falsistrellus tasmaniensis and 7 years for Gould’s long-eared bat Nyctophilus gouldi and golden-tipped bat Phoniscus papuensis. Although N. gouldi was assumed to be highly detectable in harp traps, recaptures were few and none were retrapped more than once. No female greater-broad-nosed bat Scoteanax rueppellii were captured, a minor male bias was evident for F. tasmaniensis and sex ratios were close to parity for N. gouldi, P. papuensis and eastern horseshoe bat Rhinolophus megaphyllus. Body condition and mass were mostly stable over the study and were not related to periods of drought (except perhaps F. tasmaniensis in 2019) or higher rainfall. Although we recorded some degree of site fidelity among years, the extent of any seasonal or nomadic movements remains largely unknown.