Tuesday, March 31, 2015

Do #wolves kill prey for sport?

Eric Burnham published this about 17 hours ago 
The answer is yes, but only very rarely, and under special circumstances. I ask this question because it has often come up when I have spoken with hunters. Some elk hunters argue that wolves hunt for pleasure (so called surplus killing) because this seems to provide evidence that wolves do not eliminate the weakest members of a herd, wolves do not strengthen the herd, and therefore, wolves are unnecessary at best.

When wolves kill excessively, not consuming some of the animals they kill, it is usually under one or two circumstances: (1) the snow depth is greater than 70 cm for white-tailed deer (see DelGiudice, G. D. 1998. Surplus Killing of White-Tailed Deer by Wolves in Northeastern Minnesota, Journal of Mammology, (79)1:227-235), and/or (2) the size of the pack is very small (see Zimmermann, B., et al. 2015. Predator-dependent functional response in wolves:from food limitation to surplus killing, Journal of Animal Ecology. 84:102-112). However, either case is very rare, and L. David Mech, in The Wolf, The Ecology and Behavior of an Endangered Species, reports on p. 118 that "...72% (of wolf-killed deer carcasses) were utilized 75% or more."

Further, wolves do focus on the weakest members of a herd - the very young and the very old; those animals that have a very low reproductive value. In contrast, human hunters kill those animals that have a high reproductive value. (For a great discussion of this, see Wright, W. J., et al. 2006. Selection of Northern Yellowstone Elk by Gray Wolves and Hunters, Journal of Wildlife Management. Vol. 70 Issue 4, p1070, 9p.)

However, a more basic question is how to convince those who are committed to be against wolf reintroduction. Sometimes, no evidence is good enough. In that situation, I believe it is most important to keep the dialog open, and to find some thing or things that we can agree upon. Such a process is very slow, but I try to always remain optimistic.