American Red Squirrel

 

An American red squirrel sitting on a tree branch.

NPS / BRAD SMITH

Anyone who comes to Isle Royale will have a chance to see its most visible mammal resident, the American red squirrel (Tamiasciurus hudsonicus). Unlike on the mainland they are the only squirrels and one of only a few rodents on Isle Royale. This lack of competition, along with a heavily forested habitat, has allowed these squirrels to fully populate the island.

Characteristics

Adult male and female red squirrels are the same size and can grow up to 14 inches in length including their long tail. The tail is used for balance while leaping from tree to tree, and their sharp, curved claws are used to cling to branches, bark, and even walls. They have a rust red to gray red coloration on their backs and tails, while their bellies are white.

 

Behavior

• Can be seen at all times of the day.
• Defend territory that contains caches of stored food.
• Communicate using high chatters and barks that can be heard all over the island.
• Often seen running through campsites and picnic areas.

 

A red squirrel investigating a dandelion blossom.

NPS / PAUL BROWN

Special Species?

The Isle Royale American red squirrel was once thought of as its own subspecies. Through observation, comparison, and measurements, the island red squirrels were described as having differing coloration, body size and skull size; earning the designation of Isle Royale American red squirrel (Tamiasciurus hudsonicus regalis).

This subspecies was recognized for 82 years until 2018, when a study was conducted to explore the genetics of this island resident. The study revealed that despite being smaller than mainland red squirrels, Isle Royale red squirrels had the same genetic sequences as red squirrels from across the Great Lakes and north-eastern North America.

Searching for Squirrels?

American red squirrels are often abundant in conifer and mixed forests which allows them to call the entirety of Isle Royale home. They make nests in trees out of grass, leaves, and shredded bark. They feed heavily on seeds of spruce, fir, tamarack, hemlock and pine trees. A pile of cone remnants is usually a sign that a squirrel has dined there. They also enjoy deciduous tree seeds, tree sap and berries, often storing excess food in caches in trees or holes in the ground. These squirrels are known to search park buildings, trails, and campgrounds in search of food remnants and messes left by people.

Please do not feed the squrriels! This will cause them to rely on humans for food, which can have critical impacts.

 

• 

  Red Fox

  Isle Royale fox are curious canines that scavenge for their food.

• 

  Beaver

  Beaver create important aquatic habitat for other island creatures.

• 

  American Marten

  American marten is one of four members of the weasel family on Isle Royale.