Discernment and Precaution: A Response to Cochrane and Mech

Consider the following line of thinking. For islands that are small and isolated, extinction is an authentic element of their biological integrity. A critical purpose of a park is to protect biological integrity. From those two points it would be best to refrain from conserving wolf predation as an ecological process in Isle Royale National Park and allow Isle Royale wolves to go extinct—if that is what should come to pass. Furthermore, wolves and moose might never have existed on Isle Royale were it not for human actions. As such, Isle Royale wolves and moose might be exotic species. A critical purpose of a park is to minimize and mitigate against human influences, especially exotic species. Consequently, we should celebrate the extinction of wolves and moose from Isle Royale if they were to go extinct. This seems to be the line of thinking that underlies Cochrane’s paper in this issue (Cochrane 2013). The soundness of this line of thinking can be evaluated with several considerations. Yes, of course, Isle Royale is well characterized by its island nature—a condition where extinction is common. However, being prone to extinction is not what makes Isle Royale distinctive. Humans have made most of the planet’s ecosystems prone to species extinction. What makes Isle Royale globally distinctive is being inhabited by an un-persecuted top predator, a large herbivore whose condition is not dominated by the influence of hunting, and a forest protected from commercial logging. Such landscapes used to be commonplace across the planet. Today, we have relegated these kinds of landscapes to small, isolated “islands” that are prone to extinction. It might be perverse to opt for extinction on Isle Royale, because extinction is a natural feature of islands, at the expense of actively conserving an example of biological integrity that was once commonplace but now profoundly rare because of widespread carnivore extinctions.1 The line of thinking underpinning Cochrane 2013 also depends on the belief that Isle Royale moose might be exotic species. That conclusion depends on wildly speculative evidence.2 Moreover, there are no credible plans to remove moose from Isle Royale or harvest them with the intensity that would be required to replace the influence of wolf predation.3 So long as moose are present, Isle Royale’s biological integrity and ecosystem health depends vitally on the presence of wolf predation. Allowing for the extirpation of wolf predation and the harm to ecosystem health that would ensue seems a peculiar reaction to speculation that moose inhabit Isle Royale because people brought them.