The shortest distance between the mainland and Isle Royale National Park in Michigan is about 14 miles (22.5 km). Despite that separation between land masses by the waters of Lake Superior, this national park is not without its share of wildlife. How did they get there? Some animals – like moose – are powerful swimmers. Other wildlife, like bats, birds, and insects flew over. During particularly cold winters, some animals have even crossed over on iced portions of the lake.

Red squirrels live in abundance at Isle Royale National Park / Brad Smith via NPS

What are the most commonly-seen mammals you might encounter during your visit to this national park? You’ll probably see American red squirrels. They are the only squirrels on Isle Royale and because of no competition, have populated all portions of the park.

With the hundreds of beaver ponds in the park, it’s a safe bet you might see a beaver, especially along the Minong Ridge Trail. These wetland habitats, in turn, are great for moose and waterbirds, like Canada geese and common mergansers. There’s also the possibility of spotting a bright red fox along the forest edge, in an open area, even in a campground. These beautiful canines are opportunists, so please don’t feed them.

With hundreds of beaver ponds on the island, there's a good chance you'll spot a beaver, Isle Royale National Park / NPS file

The largest mammals living on Isle Royale are moose and wolves. Prior to that, caribou thrived on the island but were extirpated (wiped out) in the 1920s. Moose are believed to have arrived around the early 1900s. Some researchers suggest moose might have crossed over ice bridges from Canada during particularly cold winters, but more than likely, they swam from island to island until they reached Isle Royale.

Where might you see a moose during your visit?

According to park staff:

Isle Royale moose can be found throughout the island. In the summer, it is common to see them feeding in inland lakes and beaver ponds. This helps them stay cool, plus they like to eat the aquatic plants that grow beneath the surface. If not in water, they tend to stay in the cool shaded forests and bogs, especially during the hottest parts of the day. They are most active during dawn and dusk.

Notable moose sighting areas on the island include:

• Washington Creek in Windigo
• Ojibway Lake
• Feldtmann Lake
• Hidden Lake in Tobin Harbor

A moose along the Greenstone Trail, Isle Royale National Park / Robert Pahre

Moose are the island’s largest mammal, standing at a height of nearly six feet (1.8 m) and weighing in around 1,000 pounds (454 kg). As such, the park has some guidelines for safe moose viewing.

• Make sure to maintain a safe distance and when in doubt, move farther away.
  
  
• If you unexpectedly come upon a moose, back away slowly and get behind a tree or rock so you are not visible.
  
  
• Watch closely for signs of agitation; if the ears go back, the moose looks directly at you, or the hair on the back of the neck stands up.
  
  
• Cows that are rearing young calves are protective. Never get between a cow and her calf.
  
  
• Bulls in autumn and fall are in rut and often aggressive. Give them more distance during September and October.

Moose are closely linked to the wolf populations on the island. Why? Wolves are the park’s apex predator and moose are a prime food source for these carnivores.

Featured on the Traveler

Radio Collars Will Help Track Moose At Isle Royale National Park

How moose at Isle Royale National Park react to the recent influx of wolves could be relatively easy to monitor now that some of the ungulates have been fitted with radio collars.

The collars were placed on 10 cow moose in mid-February by a team from the National Park Service, University of Minnesota College of Veterinary Medicine, Michigan Technological University, and Grand Portage Band of Lake Superior Chippewa. The researchers hope the collars will make it easier to assess population health, effects of herbivory, and impacts of predator restoration to the ecosystem.  

To read more of this article, head over to this page.

Speaking of wolves, they arrived on Isle Royale around the 1940s, with the prevalent belief they crossed an ice bridge that formed between the island and the Canadian mainland during the winter of 1948. Depending upon the availability of their primary food source (moose), as well as other factors including the spread of canine disease, wolf populations have varied from a high of 50 to a low of two. In a bid to revive the population while cutting down on moose overpopulation (Biologists believe the island can support 1,100-1,200 moose, but there have been as many as 2,400 living in the park), Isle Royale staff adopted a plan to bring in 30 wolves over three years beginning in 2018.

A wolf being released into Isle Royale National Park / NPS-Jacob W. Frank

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How Isle Royale National Park Biologists Chose Wolves For Their Recovery Operation

You probably wouldn't feel comfortable being uprooted from your community and tossed into a new one with three other strangers. So why did National Park Service biologists capture four unrelated wolves to begin to rebuild a population of the predators at Isle Royale National Park in Lake Superior? Part of it was strictly chance.

To read more of this article, head to this page.

New Documentary Examines Wolves Of Isle Royale National Park

How Isle Royale National Park's wolves form new packs, how researchers capture individual wolves for research, and what they learn from that research, is laid out in a documentary film released by the National Parks of Lake Superior Foundation.

To read more of this article and get the link to the video, head to this page.

You can read more about wolf relocation to the island here, and here.

Wolves are elusive creatures and wary of humans. That doesn’t mean you might not see one roaming along the lakeshores or in open areas. You might even spy a wolf along the trail. If you do see a wolf, the park has a few guidelines you should follow to keep yourself and the wolf safe:

• Do not provide food directly or indirectly. Stow your food properly to limit the smell and do not leave food or garbage in campsites or picnic areas. Dispose of fish remains in water that is at least 50 feet (15 meters) deep or at least 200 feet (61 meters) from campgrounds, water sources, and trails.
  
  
• If you meet a wolf at close range (less than 25 feet / 7.6 meters) and it does not leave or is advancing, do what you can to terminate the encounter. Back away or make noise, but do not run away. If you observe them at more than 25 feet (7.6 meters), leave the area but do not run.
  
  
• If a wolf appears to show unusual behavior, such as lack of fear of humans, please report your sighting to park staff.
  
  
• If you come upon a dead moose, keep moving away from the carcass. Wolves may be present and will be more aggressive to protect the food source. Let park staff know the location of the carcass.
  
  
• No pets are allowed on the island. Wolves are territorial and will view a domestic canine as a threat. Domestic dogs can also spread canine diseases like parvovirus and distemper, which are deadly to wolves.

A male green frog, Isle Royale National Park / NPS file

Mammals and birds are not the only wildlife inhabitants at Isle Royale. Amphibians call the park home, too, including seven documented frog and toad species. While there is no information as to how they got to the island (perhaps hitching a ride on a boat or ferry, or maybe floating over on a log?), the park does monitor their populations using audio remote recorders, or “frog loggers.” You see, toads and frogs are unique among amphibians in that they produce calls that are distinct and identifiable.

What is the difference between a toad and a frog, you might ask? According to the National Aquarium and Wild Preservation Canada, there are several main differences between frogs and toads, with the main ones being skin moisture, skin texture, and leg length. Frogs have smooth skin coated with a layer of mucus keeping that skin moist and slimy-feeling, while toads have dry, thick skin. Frogs have strong, long, webbed hind feet that are adapted for leaping and swimming, while toads have short hind legs designed more for walking and hopping shorter distances. You are also more likely to find a toad away from water, as opposed to a frog.

For a handy reference to Isle Royale National Park’s wildlife, you can view as a PDF or download as a CSV file a species list for the park.