The authors found that human killing of wolves is generally not compensatory (an increase in human-caused mortality is not offset by a decline in natural mortality). Instead, human-associated mortality may be ‘super-additive’, in that, by e.g., disrupting pack structure, it leads to additional mortality among surviving wolves. The study’s results imply that even initial wolf hunt quotas established by Montana and Idaho during the 2009 season are unsustainable, and that subsequent state proposals to increase these quotas further are likely to reduce wolf population size by a greater amount than estimated in state management proposals.
Related findings are presented in a recent study Linda Rutledge and colleagues in the journal Biological Conservation. The authors studied a wolf population in and around Algonquin Park, Canada, before and after implementation of a wolf hunting ban in surrounding townships.
The authors found that in this population, a decline in human-associated mortality was compensated for by an increase in natural mortality, such that wolf density remained constant. However, pack structure changed with the decline in human-associated mortality, with the number of wolf packs with unrelated adopted animals decreasing from 80% to 6%. The effect of hunting on the social dynamics of wolf populations may be as important as the numerical effect. Even in a relatively large protected area, hunting of wolves outside park boundaries can affect wolf social patterns within protected areas. This has implications for NRM wolf management, for example in the area surrounding Yellowstone National Park, where the 2009 hunt removed a pack that primarily resided within the park.
Although NRM wolf populations are currently back under the protection of the federal ESA, the two studies’ findings have implications for the eventual transition to state management. Both of these studies imply that conservation of populations of large carnivores will be complex and require approaches that are different than those applied to the game species that currently receive the most focus from state wildlife management agencies.