An evaluation of three restraining devices for capturing pampas foxes

Restraining is essential to many wildlife research and management programs. In an Argentine Pampas area, we studied the trapping success for the pampas fox Pseudalopex gymnocercus. We compared the capture efficiency (captures/trap days), species selectivity (fox captures/all captures), trap reliability (fox captures/fox visits), and malfunction rate (disturbed traps/trap days, of three restraining devices with different baits. In 3,495 trap days, we made 60 captures of 34 foxes and 13 other carnivores. Trapping rate differed from expected based on trapping effort, but efficiency varied little between traps, particularly between neck snares and foot-hold traps, while box traps proved less effective. Neck snares were the most selective devices, while livebaited foot-hold traps were the most reliable trap/bait combination. The lowest rate of malfunction was provided by the box trap/live bait combination. We suggest that bait type should be accounted for when evaluating trap performance.