From carnivores to small mammals, the Apostle Islands National Lakeshore is home to a diverse range of wildlife. Discover the surprising variety of species found in this national lakeshore, from state-endangered American martens to common raccoons.
The Apostle Islands in Wisconsin are home to a wide variety of wildlife, including birds, mammals, plants, amphibians, and aquatic species. The island environments, being naturally isolated, provide important habitat for these species. The islands are located at the southern limits of the boreal and northern limits of the hardwood/hemlock forests, which influences the types of wildlife that can be found there.
Mammals found in the park include whitetail deer, black bears, snowshoe hares, and other fur-bearers such as red foxes, coyotes, beavers, and otters. Small mammals like shrews, mice, voles, red squirrels, and chipmunks are also common in the park. Some mainland species, such as raccoons, skunks, porcupines, gray squirrels, and woodchucks, do not occur on the islands.
The Apostle Islands are also an important area for commercial and recreational fishing, with critical spawning areas for commercially important lake trout and whitefish near the park's lakeshore boundary. The fish community in the relatively shallow waters of the Apostle Islands is diverse and complex.
In terms of birds, the islands provide important habitat for resident breeding birds and neotropical migrants. Many of the nesting forest bird species in the Apostle Islands are migratory, and the park includes important concentration points for migratory birds during spring and fall migration. The park is also home to a variety of waterfowl, hawks, falcons, and shorebirds. Overall, the Apostle Islands are a unique and diverse place, with a rich array of wildlife that is worth exploring and protecting.
Thanks to its 21 islands and the surrounding coastal strip along the mainland. These different-sized and shaped islands, located at varying distances from the mainland and each other, and with distinct histories of disturbance, provide a unique opportunity for the study of island biogeography. Island size and distance from the mainland are important factors in determining the distribution and abundance of mammal species.
Mammals reach the islands through a variety of means. Some swim, while others cross the ice, and some even manage to hitch a ride on boats. However, species that hibernate, such as skunks and chipmunks, are not typically found on the islands. Warming conditions are causing the ice within the islands to thin and shorten in duration, and researchers are studying the potential impacts of these changes on wildlife.
White-tailed deer populations on the islands fluctuate over time due to changes in habitat conditions. In the 1940s and 1950s, deer populations increased following extensive logging, but then declined in the 1960s due to severe winters, liberal hunting, and habitat changes. Currently, low-density deer populations are found on Oak, Stockton, Basswood, and Hermit islands. While deer can swim, they are only occasionally seen on other islands.
Similarly, beavers respond to habitat changes. After logging and associated habitat alterations, beavers established and colonized all the available watersheds on Stockton and Outer Islands. However, as forests matured and favorable beaver habitat decreased, their numbers declined. Active beaver lodges can currently be found on Sand, Michigan, and Outer Islands. Like deer, beavers can swim between islands and are occasionally found on other islands.
Carnivores play an important role in the park's ecological communities. The diversity of carnivores on the islands is surprising, with ten out of the twelve carnivore species found in Wisconsin also present in the park. These include the American marten, a state-endangered species. Some species, such as black bears, are found on most of the islands, while others, like wolves, are rare on the islands but present on the mainland. Other carnivore species found in the park include coyotes, red and gray foxes, bobcats, fishers, otters, weasels, and raccoons.
Small mammals also contribute to the health and biodiversity of the park's ecosystems. There are ten small mammal species found in the park, four of which are only found on the mainland. Red-backed voles, a favorite food of American marten, are the most abundant small mammal species on the islands. Other island small mammal species include red squirrels, deer, mice, and common and short-tailed shrews. The small mammal species only found on the mainland include eastern chipmunks, meadow jumping mice, eastern meadow voles, and flying squirrels.
For more information about the Apostle Islands, visit the park's website. There you will find additional details and resources about the park's natural and cultural history, recreational activities, and visitor services. The website is a great resource for planning your visit and learning more about this unique and beautiful place.