Comparative efficacy of Longworth, Sherman, and Ugglan live-traps for capturing small mammals in the Nearctic boreal forest

Abstract

Understanding the efficacy of various types of traps is important in the design of field studies. Surprisingly, few studies have compared the relative efficacy of different types of commercially manufactured live-traps for capturing small mammals. I compared the performance of Longworth, Sherman, and Ugglan small mammal live-traps in Nearctic boreal forests. All three trap types were simultaneously set at 275 trapping stations, and animals were provided a choice of traps to enter. Number, sex, and age class of captures as well as mortality and recapture rates were compared among trap types. Captures were dominated (87 %) by red-backed voles (Myodes rutilus). Sherman traps captured significantly fewer animals than did either Longworth or Ugglan traps, but there was no difference in the sex or age class of individuals captured among trap types. Percent of mortalities varied by trap type, with the highest percentage of mortalities occurring in Sherman traps. Red-backed voles captured in Sherman traps had a significantly higher likelihood of not being recaptured again in a Sherman trap. Overall, this study found that Longworth and Ugglan traps performed similarly with respect to capturing red-backed voles and deer mice (Peromyscus spp.) in boreal forest. Sherman traps, however, were not as efficient. This difference may be particularly significant for studies relying on mark-recapture data. The relative efficacy of different trap types is likely species- and habitat-specific, and further studies in different environments are necessary. These data may assist researchers in making objective choices of which type of live-trap to employ in their research and in critically comparing results from studies using different trap types.