Dr. L. David Mech was one of the plenary session speakers at the Midwest Fish & Wildlife Conference, held on 11 – 15 December in Minneapolis, MN. Dr. Mech gave a thought-proving presentation on the science related to wolves, with a special focus on wolf effects on ungulates, scavengers, and the so-called “trophic cascade” in Yellowstone that has been attributed to the presence of wolves.
Mech reviewed the research on these subjects and essentially concluded that the science is far from settled. He emphasized the tentative nature of these findings and noted that there was often conflicting evidence from competing labs.
One area where he felt the science was very robust concerned wolves’ tendency to kill weak and vulnerable animals with greater frequency then would be expected by chance. He played a very interesting video from wildlife photographer Bob Landis that appeared to show wolves specifically targeting an elk with a visible limp (later confirmed to be arthetritis) after “testing” other animals in the herd. He suggested this was the first really solid evidence that wolves’ disproportionate take of vulnerable animals was not just due to these animals’ vulnerability, but also a function of wolves’ behavior–that is, that wolves specifically target more vulnerable animals. Folks that want to learn more can visit http://www.davemech.org.
Q & A
I was particularly interested in a couple of questions Mech fielded at the end of his presentation. When asked how managers should respond to recent comments from northern Minnesotans that wolves “were decimating deer populations”, Mech quipped that they had been saying the same thing since he started studying wolves (back in the late 1950s).
Mech was also asked to predict the geographic extent of wolf recovery (i.e., where will wolves be 20 years from now). He opined that wolves would continue to occupy some new territory in southern Wisconsin and Michigan and probably the Dakotas as well, but would probably never be able to survive in states like Illinois and Indiana. He felt the Rocky Mountain population would do better, expressing confidence that wolves would make it into Utah and Colorado and even northern California.
Another questioner asked how hunting wolves was going to build tolerance for the species if, as Mech had maintained, hunting would have little effect on wolf populations. Rather than address this directly, Mech pointed to Poland where he asserted that wolves had gone through three cycles of “overprotection” followed by wolf eradication, implying that the same could happen here in the U.S. While I would concede Mech’s point, I would argue that, given the differences in our culture and system of government here in the U.S., one cannot assume that the same events will transpire–in fact, the science on the matter is certainly less clear than it is on any of the issues Mech had argued were far from settled. Personally, I happen to agree with Mech’s assessment that this is a legitimate risk; in fact, that was essentially the argument we made in a recent paper. However, I think it is important to note that our collective understanding of the social and political systems that will decide whether similar events transpire here in the U.S. is no better than our understanding of trophic cascades–the science is far from settled.