04-09-11 Field Note: Minks, Fishers, and Mountain Lions

Beau Larkin's field note discusses the difference between mink and fisher and reveals hair-snare traps set on MPG North.

Posted on 4/9/2011 by Anonymous

Habitat Types: 


Field Guide Entries: 

Mountain Lion
White-tailed Deer
Snowshoe Hare
MPG North Field Note Medium-sized mustelids on MPG North: minks or fishers? 9 April 2011, MPG Operations, Beau Larkin
How can we distinguish minks from fishers? Fishers are larger than minks, but both species show strong sexual dimorphism. A female fisher can be smaller than a male mink. Camera 4 captured the animals in images 1 and 2 at about the same distance. Crude head to tail measurements on the photographs revealed that animal 2 is 86% of the length of animal 1, but image 2 captured the mustelid in a constricted body posture. Stretched out, this animal could be the same size as the first one. Size comparison...
Northwest Connections’s field technician Ad- am Lieberg placed hair-snare traps in the Swan Valley this winter to collect DNA sam- ples of fishers and study their movement and dispersal. We rigged three of these traps on MPG North (inset map) in an attempt to con- firm the presence of fishers. The traps sus- pend bait (in this case, bison meat) between stiff wire brushes (image 3).
Place more hair-snare traps next winter to learn about medium-sized mustelid populations.  Mustelids disperse to avoid territorial battles and find good food sources. Exposed winterkill could at- tract fishers this time of year. Opportunist minks look for any good reason to stick around—they have small home ranges. Efforts to improve/create suitable hunting and especially denning habitat for these carnivores will increase the chance that a dispersing female will make a home on MPG North. Fishers use...
A sly mountain lion evaded camera capture... Mountain lions’ usually stride 19-32”. This one stepped out 38” (red line, individual registers in cir- cles) in hot pursuit of the white-tailed deer that use this game trail (location: inset map).