American mink (Neovison vison) trapping in the Cape Horn Biosphere Reserve: enhancing current trap systems to control an invasive predator

Improvement of invasive American mink (Neovison vison) trapping methods in the Cape Horn Archipelago is a priority for wildlife managers. We assessed the use of cubby sets (16 x 16 x 30 cm plywood boxes) containing body gripping lethal traps to control mink along the Beagle Channel. We compared effectiveness, selectivity and weather condition resistance between two cubby set designs: (i) open front, and (ii) restricted entrance (lidded with a 6 cm aperture). The effectiveness of bait was evaluated between fresh versus canned fish. Thirteen minks and no non-target species were captured with the restricted entrance systems, as compared with three minks and 25 non-target individuals (six species) in open front cubby sets. Fresh fish resulted in more captures than canned fish, and lids made traps less susceptible to false activation. Traps inside restricted entrance cubby sets, baited with fresh fish were found to be most suitable for mink control and/or eradication efforts.