Impact of an experimental wolf reduction on beaver in Papineau-Labelle Reserve, Quebec

Abstract

From 1983 to 1988 the densities of beaver colonies in traplines from within two blocks were compared. The first block (RB, 275 km2) was included in a larger area where wolves were reduced almost 60% over three winters. The second block (UB, 265 km2) received no wolf-control treatment. Beaver trapping, formerly prohibited, was allowed in 1984 in 5 of 11 trapline units of RB and 5 of 9 units of UB after the first wolf reduction. The density of colonies (0.8/km2) remained stable in UB, even where beaver trapping was allowed. In RB a 20% increase in colonies occurred after 3 years in units not opened to beaver trapping, but the numbers decreased to their former level 2 years after wolf control was terminated. Where wolf reduction and trapping occurred synchronously, colony numbers remained unchanged, but they decreased by 30% following suspension of wolf control. We do not recommend wolf reduction as a management tool when beaver density is high. POTVIN, F., BRETON, L., PILON, C., et MACQUART, M. 1992. Impact of an experimental wolf reduction on beaver in Papineau-Labelle Reserve, Quebec. Can. J. Zool. 70 : 180-183. De 1983 a 1988, nous avons compare la densite des colonies de castors entre un bloc (RB, 275 km') oh le nombre de loups a etC reduit de prks de 60% durant 3 hivers et un bloc temoin (UB, 265 km').Interdit avant 1984, le piegeage du castor a Ct C autorisk, aprks la premikre reduction du loup, dans 5 des 11 terrains de RB et 5 des 9 terrains de UB. La densite des colonies (0.8/km2) est restke stable dans UB mCme la oh le piegeage Ctait permis. Dans RB, on a not6 aprks 3 ans une hausse de 20% du nombre de colonies dans les terrains non piCgCs, mais ce nombre est revenu a son niveau initial 2 ans aprks 1'arrCt du contrale. La oh la reduction du loup et le pikgeage du castor furent exerces en mCme temps, la densite des colonies de castors n'a pas variC, mais elle a chute de 30% quand le contrale du loup fut interrompu. Nous concluons que la reduction du loup n'est pas une pratique d'amknagement justifiable quand la densite du castor est klevee.

Food habits of wolvesCanis lupus in Latvia

“…Wolves in some areas in North America helped to decrease beaver colonies (Potvin et al 1992), provided that both wolf and beaver populations reached high levels (Shelton and Peterson 1983). In Latvia, wolves seemed to have little effect on the increasing numbers of beavers.…”

Possible Tool Use by Beavers, <em>Castor canadensis</em>, in a Northern Ontario Watershed

“…In boreal situations, such as the CCGP, a lessening of foraging time means reduced exposure to Gray Wolves. Potvin et al (1992) demonstrated that Gray Wolves are highly effective predators. In subsequent studies, Basey and Jenkins (1995) further showed that Beavers actually trade off maximum profitability against minimization of Wolf predation.…”

Evaluation of an experimental wolf reduction and its impact on deer in Papineau-Labelle Reserve, Quebec

“…We hypothesized that wolf density would decrease and that deer numbers and density, the buck harvest, and fawn survival would all increase as a result of wolf control. The effects on beaver are presented elsewhere (Potvin et al 1992). …”