Modifications of Longworth traps to prevent wear and improve catchability of shrews (Sorex spp.)

Abstract Longworth live traps are widely used for trapping mouse-sized rodents and shrews. However, they have a number of disadvantages: some have a manufacturing defect, resulting in reduced sensitivity; smaller species of shrews can pass under the treadle, avoiding capture; captured animals can gnaw specific parts of the sidewalls and decrease the durability of the traps. To increase the efficiency of catching small shrews, we added a movable tin ramp to the treadle of the Longworth live traps and used washers to improve the design. To repair and protect traps damaged by captured animals, we used tin patches. The modified traps were shown to be significantly better than the original traps in catching small shrew species (Sorex caecutiens Laxmann 1788, Sorex minutus Linnaeus, 1766). Tin patches reliably protected live traps from further damages by animals and do not affect their catching efficiency.