Isle Royale Wolves: I Vote for Nature's Way
By Franz Camenzind
Isle Royale is both a National Park (1940) and a designated Wilderness Area (1976). Each authority brings significant protection to the land, but with differing mandates. As a National Park, its clear purpose is to preserve and protect its wilderness character, cultural and natural resources, and ecological processes; where humanity's protectionist's footprint may be very apparent.
As a Wilderness, its clear purpose is to protect the area so as to preserve its natural conditions in a manner that generally appears to have been affected primarily by the forces of nature; where humanity's preservationist's footprint leaves at most, only a faint impression.
These mandates contain contradictions that may seem subtle to most, but they can confound management decisions. Isle Royale, known for its wolf population, is facing a critical decision point-to physically import wolves from the mainland to "rescue" the current isolated population which is likely to "blink out" in the next year due to the consequences of severe inbreeding or, to leave nature alone and allow the island's wolf population to disappear. Wolves first arrived on the island in the late 1940s via an ice bridge from the mainland, but their stay appears to be a short one. The question is whether to allow a natural event (likely extirpation) to play out, as was the case when wolves first arrived on the island, or to intervene and extend the wolves tenure by translocating wolves from mainland.
We now face a situation where some argue that the Park's mandate allows for the heavy footprint of an artificial reintroduction of wolves to keep a functioning wolf population on the island. Others argue that the wilderness designation means managers should leave nature to take its course and preserve the area's wild and untrammeled condition even if that means the end of the wolf population on the island. It is nature's way.
Adding to the decision's challenge is the argument that Isle Royale without wolves will result in a moose population explosion (the wolf's major food source and the moose's only significant predator), which will lead to severe over-browsing and long-term habitat damage. Wilderness advocates argue that this impact too would pass. If over-browsing occurs and moose populations subsequently decline, the habitat will very likely rebound. This happened before wolves arrived on the island (moose predate wolves on the island by several decades). It's nature's way.
Although their origins are uncertain, what is known is that moose first appeared on Isle Royale at the very beginning of the 20th Century, decades before the first wolves arrived. It is widely accepted that the particularly cold winter of 1948-49 allowed an ice bridge to form, which in turn allowed the first wolves to cross the 15 miles from the mainland to the island. However, for nearly half a century the island, and its moose, survived without wolves. Interestingly, during that wolf-free period, it is quite clear that moose had severely over-browsed their forest habitat and were on the verge of starving out. Not surprisingly, the habitat recovered, and so did the moose population.
Scientists say that moose populations are controlled by available forage as much or even more so than by the presence of wolves. Clearly, for decades, the two acting together have made for a very interesting and natural dynamic. But in the long course of ecological events, their decades-long drama may have been nothing more then a brief relationship.
I vote for nature's way. I do so because ninety-nine percent of Isle Royale's 134,000 acres is Wilderness, and so a different type of "management" is required for this place, one that respects the area's wild character and does not try to manipulate wildlife populations or habitat conditions on the island. In other words, impose a management decision not to manage.
I also support nature's way because capturing and hauling wolves in from the mainland will not alter the overriding reality-Isle Royale is an island only occasionally connected to the mainland by an ice bridge. By itself, the island is too small to sustain a long-term, genetically healthy wolf population, and perhaps the same can be said for the moose population. I have to ask, if a "rescue" were to occur, when would inbreeding again overtake the isolated wolf population and when would demands for another "rescue" be made? Would this human manipulation become the new normal? How is this natural? How does this leave the Wilderness untrammeled? How does this maintain the Park's or its Wilderness' natural processes?
Some rescue proponents insist that if the island's wolves die off, over 60 years of wolf-moose research will come to an end. Without a doubt, the Isle Royale wolf-moose dynamics have been superbly documented throughout this time as the longest major predator-prey study in history. However, if wolves are purposely brought onto the island, what will it do for the continuity of the research? It will effectively change a natural study paradigm into a manipulated (island) laboratory research project, one whose results will always require a disclaimer that the findings were influenced by human intervention and no longer represent a naturally occurring phenomena.
In effect, it would be new research that could best be described as a "before and after" intervention study and difficult to claim as an uninterrupted, continuation of the previous work.
Proponents of wolf "rescue" also argue that with climate change, ice bridges and natural re-colonization by wolves are less likely to occur, therefore human intervention is justified, if not necessary. A logical scenario, but other climate-driven factors are also coming into play on the island. Perhaps most significant is the documented change already occurring in the vegetative regime on the island, a change not favoring the moose population. As the habitat's vegetation shifts away from moose-preferred species, will the moose population again be put in jeopardy? If this is the case, do we "rescue" the moose population too? Or do we initiate a wolf reduction program to safeguard the remaining moose? Or do we initiate a moose reduction program in an attempt to safeguard the remaining habitat? Where does this intervention end?
We forget that Isle Royale is an island and cannot operate like an expansive and complex mainland landscape. Like most island settings, its species composition is much simpler then the nearby mainland. For example, only 19 species of mammals occur on the island compared to over 40 on the surrounding mainland. Consequently, its ecological systems are far simpler then those operating on the mainland. And because of its limited size, it cannot support populations of low density species such as the wolf or other large carnivores that require large, connected landscapes to sustain their own numbers, and their own genetic diversity. And we forget that as far back as 3,500 years ago, the island was home to woodland caribou and Canada lynx. And coyotes made it to the island on their own around 1905, but disappeared by 1955. Consensus is that they were all eliminated due to human actions. Do we re-colonize the island with these previous, naturally occurring residents, ones lost not naturally, but through deliberate human actions? We face a dilemma of conflicting values; not one solved with on-going intervention. When would it end?
And last, the decision to "rescue" the island's wolf population might be easier to accept if doing so would be a step toward saving the species from extinction. This is not the case. What happens to the wolves of Isle Royale will have little to no impact on the species' overall survival.
Allow Isle Royale to be a wilderness park, let its future be shaped as it was during its not so distant past-by nature's forces, not humankind's manipulated version of a "natural" island system. Then and only then can we observe and learn how island ecosystems truly function. There aren't many places like this left in the world, let us not spoil it with heavy-handed intervention.
Franz Camenzind, Ph.D.
Franz is a wildlife biologist and the Vice-President of Wilderness Watch's board of directors.