Evaluation of the ethical, scientific, and financial performances of Elliott and pitfall traps for sampling small desert-dwelling mammals

Trapping is resource intensive and has animal welfare implications. We compared the ethical, scientific andfinancial performances of Elliott traps and two pitfall trap designs (shallow/wide and deep/narrow) forestimating diversity and sampling small mammals in an arid environment. Shallow and deep pitfalls sampledapproximately 79.0% and 85.0% (respectively) more small mammals than Elliott traps. Deep pitfall trapssampled the greatest diversity and number of small mammals, and number of small mammal species andindividuals per dollar. Elliott traps were the least efficient traps on most scientific and cost measures,recording the greatest overall recapture rates, and particularly for Sminthopsis crassicaudata and S. macroura(41.2% and 47.6% higher in Elliott traps than in shallow or deep pitfall traps, respectively). Body size of onespecies only, the nationally-threatened Pseudomys australis, influenced its capture rate, with larger individualsmore likely to be caught in deep pitfalls. Mortality was highest in pitfalls and mostly related to interactionsbetween trapped animals. Deep pitfalls likely detect species that can escape shallow pitfalls and were mostcost-effective for sampling small mammals. Some of the ethical issues associated with pitfall traps could bemitigated by checking traps more often at night during periods of high abundance.