REDUCING NON-TARGET MOOSE CAPTURE IN WOLF SNARES

Craig Gardner

Abstract


I investigated the characteristics of moose (Alces alces) bycatch in kill snares set for wolves (Canis lupus) in interior and south-central Alaska, USA. My objective was to design a kill snare that would reduce moose vulnerability and injury if captured without reducing its effectiveness for capturing wolves. I documented at close range (<30 m) snare encounters by captive moose in natural habitat at the Kenai Moose Research Center (MRC) in south-central Alaska. Moose contacted 153 cm or 183 cm snares (n = 184) with their chest-shoulder area (59.8%), neck-head region (34.2%), upper legs (3.8%), and along the ribs (2.2%). I documented the fate of moose following 225 snare contacts; 13.8% were captured by the nose (5.8%), leg (4.9%), or unknown (3.1%) with the remainder either knock-downs (65.3%) or push-asides (21.0%). Moose did not attempt to avoid snares. Of the 147 knock-downs, 86.4% formed a loop 15-38 cm in diameter that laid near the snow surface continuing to present a potential trap for moose. I also evaluated capture rates by loop size for wild moose in 3 study areas in interior Alaska. Capture rate and type were not influenced by snare loop size or snow depth in the wild or the MRC. Capture vulnerability of wild and captive moose was higher in snares that were knock-downs by other moose or wind. I subsequently developed a snare that incorporated an additional wire (diverter) placed at a height that allowed moose or any ungulate taller than the set height of a wolf snare to contact and push the snare away prior to contact. This design reduced the vulnerability of moose but not wolves to capture. I also placed a cinch stop at 24.1-26.7 cm from the end stop of the snare loop to reduce injury to moose and act as a breakaway system without reducing the snare's effectiveness for capturing wolves. Results of this study are applicable to areas where wolf or coyote (Canis latrans) snaring occurs in the presence of moose and other large hoofed mammals.


Keywords


accidental capture; Alaska; Alces alces; breakaway snares; Canis lupus; moose vulnerability; snare effectiveness; snare efficiency; trapping; wolf snares; wolves

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