Trapping efficiency and associated mortality of incidentally captured small mammals during herpetofaunal surveys of temporary wetlands

Abstract

ABSTRACTPitfall‐trapping used in conjunction with drift‐fence arrays is a common and effective means for detecting herpetofauna and small terrestrial mammals. A concern when using less‐selective trapping methods is the impact of capture on target and non‐target species. We compared capture and mortality rates of non‐target species during a herpetofaunal study of temporary wetlands on forested lands in Mississippi, USA, March 2004–March 2006. We compared rates from pitfall traps, double‐ended funnel traps, and pitfall traps combined with anti‐predator wire exclusions along drift‐fence arrays in 4 isolated upland and 6 floodplain ephemeral pools. We monitored traps daily for 23 5–10‐day trap periods over a 2‐year period. We captured 10 small mammal species (216 captures) on upland sites and 8 species (256 captures) on floodplain sites. Southern short‐tailed shrews (Blarina carolinensis) and mice (Peromyscus spp.) accounted for 94% of total captures. Southern short‐tailed shrews and mice suffered 76% and 52% mortality. Capture and mortality rates for small mammals were similar in un‐excluded pitfall traps and excluded pitfall traps. Because of potential impact of pitfall‐trapping on small mammals, we recommend researchers either alter trapping methods to address mortality in non‐target species or work cooperatively using an integrated survey approach for both herpetofauna and small mammals. © 2014 The Wildlife Society.