Compared to the rest of the contiguous U.S., Isle Royale is extremely isolated. It’s so isolated that only a few mammal species reside here. You’ll find more than 40 mammals on the surrounding mainland, but only 18 inhabit the park. Species like caribou and coyote have disappeared. Others, like moose and wolves, have found a way to reach the island within the last century. It’s widely believed that moose, excellent swimmers among the animal kingdom, swam to the island, motivated by the scent of abundant vegetation. Wolves arrived a few decades later when an exceptionally cold winter left the passage between Ontario, Canada and Isle Royale frozen solid. The presence of moose and their natural predator, wolves, in a closed environment such as Isle Royale creates an ideal setting to study predator-prey relationship. Scientists have studied the park’s wolves and moose since 1958. You can even lend a hand by joining a research expedition ($450 for 9 days). Find out more at www.isleroyalewolf.org. In addition to these larger mammals, snowshoe hare, beaver, red fox, red squirrel, at least 40 species of fish, and a handful of amphibians and reptiles reside in the park. Pests are also abundant. Mosquitoes, black flies, and gnats are worst in June and July.
The island is primarily forested with a mixture of boreal and northern hardwoods. Spruce, fir, pine, birch, aspen, maple, and ash are commonly found. Blueberries and thimbleberries grow wild on open ridge tops. They typically ripen between late July and August, providing a tasty snack while hiking about the island.