Greetings from the frozen north woods! Came across some interesting research while I was warming myself by the wood stove.  In this study, wolf urine showed itself to be an effective way to deter beavers. Don’t take my word for it – read their conclusions for yourself.(Italics mine)

Predator cues reduce American beaver use of foraging trails

WILLIAM J. SEVERUD, Northern Michigan University, Department of Biology, 1401 Presque Isle
Avenue, Marquette, MI 49855, USA wseverud@nmu.edu
JERROLD L. BELANT, Carnivore Ecology Laboratory, Forest and Wildlife Research Center, Mississippi
State University, Box 9690, Mississippi State, MS 39762, USA
JOHN G. BRUGGINK, Northern Michigan University, Department of Biology, 1401 Presque Isle
Avenue, Marquette, MI 49855, USA
STEVE K. WINDELS, 360 Highway 11 East, International Falls, MN 56649, USA

Discussion

We found a 95% reduction in beaver numbers at camera stations containing predator urine, indicating that beavers altered their space use in response to an indirect cue of predation risk. Beavers also spent 95% less time at urine-treated camera stations and exhibited no decrease in time spent at control camera stations. Decreased time spent at urine-treated camera stations suggests that antipredator behavior in beavers in our study area was strong, consistent with the risk allocation hypothesis (Lima and Bednekoff 1999). Decreased use and time spent at urine treated camera stations suggests that wolf urine is an effective deterrent to beaver activity and that beavers use olfaction to assess predation risk. In our study area, wolves have large territories and range extensively (Mech 1974); hence, beavers may experience only occasional temporal pulses of risk from wolves. These pulses of risk may be perceived by beavers regardless of actual predation events, which may be affected by available alternate wolf prey (Voigt et al. 1976). Although our study was short in duration, it represented a brief pulse of elevated predation risk. That beavers avoided camera stations containing wolf urine supports the tenet of the risk allocation hypothesis, which states that brief, infrequent pulses of high risk will elicit strong antipredator behaviors in prey species (Lima and Bednekoff 1999). Our data suggest that beavers either reduced total foraging activity or began using unmonitored or untreated trails. American and Eurasian beavers both have exhibited use of olfaction to assess risk by repressing scent-marking behavior (Rosell and Sanda 2006) and foraging (Engelhart and Müller-Schwarze 1995, Rosell and Czech 2000) in response to predator odors.

Well, I’d better go put another log on the fire. Have a good one! The PeeMan