Yet their return has not been well-received by everyone. The US has seen an increase in their wolf populations across the country, and extensive conservation efforts have led to a comeback across Europe. But after decades of habitat destruction and human persecution, wolves now only occupy about two thirds of their former range. They were once one of the most widely distributed wild mammals on Earth. Relationships among wolves, their prey, and the environment have been affected by:ĭue to the wolf population decline in recent years, Isle Royale National Park decided to relocate wolves to the park in hopes to restore an apex predator in island predator-prey relationships.Over the last decade, wolves have been at the center stage of conservation news.

The National Park Service and Michigan Technological University have collaborated to conduct the longest consecutive predator-prey study that focuses on the relationship between wolves, moose, beaver, and vegetation. This graph displays how Isle Royale predator and prey populations have varied through time. Graph retrieved from Wolves and the Isle Royale Environment 2018-2020, NPS and SUNY-ESF. The island ecosystem may seem simple at first glance, but relationships between island predator and prey are more complex than is readily apparent.Įstimated abundance of wolves, moose (NPS and MTU, unpublished data) and beaver (NPS, unpublished data), Isle Royale National Park, Michigan, USA, 1958-2018. The relationships between prey and predator are constantly changing and that dynamic can be influenced by any number of environmental factors. Dropping from 50 to 12 in just two years, this change shifted the ecosystem from one where wolves had a greater influence on the prey population, to one where climate, available forage, and other undetermined factors were more influential. In combination with decreasing populations of both moose and beaver, a likely increased amount of wolf on wolf mortality related to food shortages, and the canine parvovirus (CPV2) disease outbreak which greatly reduced the number of pups surviving into adulthood, the Isle Royale population of wolves, naïve to this strain of the virus, was significantly impacted. In one study, wolves were demonstrated to have a larger impact on the moose population prior to a disease outbreak within the wolf population than after. Many internal and external factors influence the populations of island predator and prey.Ībundance of prey on Isle Royale is undoubtedly influenced by the number of wolves, however, many other factors impact both moose and beaver populations. Predator-Prey Relationships: Wolves-Moose & BeaverĪlthough considered a relatively simple ecosystem when compared to the mainland, the relationships between moose, beaver, and wolves on Isle Royale are quite complicated. One thing is certain- their island existence is interconnected. The populations of wolves, moose, and beavers have fluctuated over time. Scientists have been asking similar questions about the predator-prey relationships on Isle Royale for over sixty years. What if an island lacked an apex predator? What if prey roamed unchecked on a secluded landscape?

Wolves directly impact how many moose and beaver there are at Isle Royale National Park. Other large predators are absent from the island, such as bears, coyotes, and mountain lions. Wolves have been the single island apex predator of moose and beaver since the late 1940s. What would happen if only one predator inhabited an isolated ecosystem? Isle Royale's isolation limits the number of species a part of its ecosystem. Hibernating animals miss the chance to cross an ice bridge that sometimes forms between the mainland and the island. Animals that hibernate in the winter do not inhabit the island-like bears. Large mammals like wolves, moose, and beaver have made the journey. Not all mainland species are found on remote Isle Royale. What if an ecosystem was unreachable for some species? Vucetich, Michigan Technological University They prey on moose, beaver, and snowshoe hare.

Are wolves moose predators