Isle Royale is an island located in Lake Superior, about 15 miles southeast of Thunder Bay, Ontario. The island is 45 miles long and 9 miles wide at its widest point, with an overall land area of 206 square miles. Isle Royale is home to a large variety of bird species due to its remote location and diverse range of habitats including northern hardwood and boreal forests, swamps, bogs, ponds, and coastal regions along Lake Superior. Over 200 species of birds have been documented on the island. In this article, we will provide an overview of some of the most notable bird species that can be found in the Isle Royale National Park throughout the year.
Spring and Summer Breeding Birds
During the spring and summer months, Isle Royale serves as an important breeding ground for many migratory bird species. Some of the most common breeding birds on the island include:
Warblers
Isle Royale hosts over 30 species of warblers during the spring and summer months. Some species such as the Nashville Warbler, Chestnut-sided Warbler, Magnolia Warbler, Yellow Warbler, and American Redstart are abundant breeders across the island’s forests. Other warblers like the Cape May Warbler and Blackburnian Warbler breed in smaller numbers in the island’s boreal forest regions. The warblers arrive in late April-May to breed and nest, departing by late August-September.
Sparrows
Several types of sparrows breed on Isle Royale including the Song Sparrow, Swamp Sparrow, and Savannah Sparrow. The Fox Sparrow can also be found nesting in thickets and forest openings. These small seed-eating birds arrive in early spring and remain on the island through the summer to raise their young before migrating south again in fall.
Wrens
The small and energetic House Wren and Winter Wren are summer residents on Isle Royale, favoring shrubby areas and forest openings near water for breeding and foraging. Their loud and complex songs are a common sound heard during summer hikes on the island.
Woodpeckers
Isle Royale provides prime nesting habitat for woodpeckers including the Downy Woodpecker, Hairy Woodpecker, Northern Flicker, Pileated Woodpecker, and the Yellow-bellied Sapsucker. These woodpeckers drill cavities in trees for nesting and feed on insects and larvae they dig out from tree bark.
Flycatchers
Several species of insect-eating flycatchers summer on Isle Royale such as the Alder Flycatcher, Least Flycatcher, and Eastern Phoebe. These birds perch on branches and dart out to catch flying insects, often returning to the same perch. Their calls are a very noticeable part of the soundscape of Isle Royale’s forests in summer.
Thrushes
A number of thrush species breed on the island including the American Robin, Veery, Swainson’s Thrush, and Hermit Thrush. These ground-dwelling birds consume insects, fruits and berries, and lay their eggs in nests on the forest floor or in the lower branches of trees and shrubs. The males sing beautiful flute-like songs from the treetops through the late spring and summer months.
Owls
Several owl species reside on Isle Royale and nest in the forests and along rocky ridges and shorelines. The Barred Owl is the most numerous owl, while the Northern Saw-whet Owl and Boreal Owl are also regular island nesters, though in smaller numbers. These nocturnal hunters prey on small mammals, other birds, and insects.
Loons
Common Loons and Red-throated Loons both breed on Isle Royale’s inland lakes and along its coastlines. These diving birds arrive in spring to establish breeding territories on the water and build floating nests along shorelines to hold their eggs. Their eerie calls echo across the island’s lakes through the summer.
Grebes
Pied-billed Grebes and Red-necked Grebes are summer residents on the island, inhabiting marshes, beaver ponds, and other still or slow-moving water bodies. They build floating nests and dive to catch small fish and aquatic invertebrates.
Terns and Gulls
Several species of terns including Common Terns, Caspian Terns, and Black Terns nest in colonies on rocky Lake Superior shorelines and islands around Isle Royale. Ring-billed Gulls, Herring Gulls, and Great Black-backed Gulls also establish nesting colonies here, often sharing sites with the terns.
Osprey
These large fish-hawks arrive in spring to build nests atop dead trees and cliff ledges overlooking water where they can hunt for fish. The Osprey’s high, whistling calls are a frequent sound along Isle Royale’s shorelines through the summer.
Bald Eagle
Bald Eagles breed in small numbers across the island, building enormous nests high up in trees near lakes and coastal areas that provide ample fish on which to feed their young. Isle Royale hosts one of the Great Lake’s highest densities of breeding Bald Eagles.
Winter Residents
While most songbirds migrate south for the winter, Isle Royale remains an important wintering ground for certain northern bird species including:
Snowy Owl
Isle Royale marks the southern edge of the breeding range for these large white owls that nest on the Arctic tundra. However, Snowy Owls regularly overwinter on the island where they hunt for small mammals in open areas near the shore.
Rough-legged Hawk
These large raptors breed in the Arctic then migrate south to spend the winter months on Isle Royale where they hunt for small mammals in open habitats. Dark morph and light morph Rough-legged Hawks are both regularly observed here in winter.
Northern Shrike
This predatory songbird is a year-round resident on Isle Royale favoring open shrubby areas. Shrikes skewer prey like small mammals, insects, and even birds on thorns or barbed wire to cache for later feeding.
Black-capped Chickadee
These active little songbirds are permanent residents across the island. Flocks of chickadees can be seen foraging throughout the forests and at backyard bird feeders all winter long.
Boreal Chickadee
This northern relative of the Black-capped Chickadee resides year-round in Isle Royale’s coniferous forests. Boreal Chickadees have a brown cap and harsh call that distinguishes them from Black-capped Chickadees.
Red-breasted Nuthatch
These agile little birds creep up and down tree trunks probing bark crevices for insects and seeds. Red-breasted Nuthatches remain on territory all winter on Isle Royale.
Gray Jay
Also known as the Canada Jay, this tame year-round resident bird frequents campgrounds and readily takes handouts. Gray Jays uses their sticky saliva to cache food to eat later in the winter.
Year-Round Residents
In addition to the winter resident species, the following birds may be spotted on Isle Royale at any time of year:
Common Raven
These large, intelligent corvids are abundant residents across the island. Ravens form lifelong pairs and use their heavy bills to feast on just about anything including fruit, eggs, small animals, and carrion.
Blue Jay
This familiar backyard bird stays on Isle Royale all year round where it stores acorns and other seeds to eat during the winter months. Blue Jays are very vocal birds with a huge repertoire of calls.
Red-tailed Hawk
Look for these broad-winged raptors year-round soaring over open areas as they hunt for small mammals and birds. Red-tails build stick nests high up in trees.
Ruffed Grouse
These chicken-like birds reside across the island’s forests year-round. In spring, male grouse perform a drumming display by rapidly beating their wings to attract mates.
American Crow
Crows form family flocks that occupy territories year-round on the island. These intelligent birds often gather in large night-time roosts during winter.
Common Goldeneye
This diving duck can be spotted on inland lakes and Lake Superior all year long. Male goldeneyes have a striking white facial patch and breed on the island in late winter-early spring before migrating south.
Mallard
This familiar dabbling duck occurs across the island. Mallards form pair bonds by late winter before females lay eggs in nests on the ground in secluded wetland areas in spring.
Rock Pigeon
Feral populations of these pigeons, native to Eurasia, thrive around developed areas on the island where they can roost on buildings and scavenge for food.
Downy Woodpecker
These common little woodpeckers can be seen year-round across the island probing tree bark for larvae. Downies are the smallest woodpecker in North America.
Hairy Woodpecker
Slightly larger than the Downy, Hairy Woodpeckers forage on tree trunks across the island’s forests all year long. Listen for their sharp, repetitive “peek” calls.
Pileated Woodpecker
These crow-sized woodpeckers are the island’s largest and use their powerful bills to excavate large, rectangular cavities in dead trees in mature forests where they reside year-round.
Great Horned Owl
Look and listen for these large, tufted owls year-round. Pairs defend nesting territories across the island and have a deep hooting call, often answered by other owls.
Migratory Species
In addition to the resident species, Isle Royale hosts a diversity of migratory birds that pass through in spring and/or fall on their way between wintering and breeding grounds, including:
Shorebirds
Many types of sandpipers and plovers stop to rest and feed on the island’s beaches and mudflats during spring and fall migration including Lesser Yellowlegs, Solitary Sandpiper, Spotted Sandpiper, Semipalmated Plover, and Killdeer among others. These migrants feed on invertebrates in the intertidal zone.
Waterfowl
A wide array of ducks and geese can be seen migrating past the island in spring and fall including Greater Scaup, Surf Scoter, Long-tailed Duck, Bufflehead, Red-breasted Merganser, Canada Goose, and Common Merganser. Many waterbirds also pause to rest on the island’s inland lakes and coastlines during migration.
Loons
In addition to the breeding loons, several other loon species migrate past or even briefly stopover on the island during spring and fall passage. These include the striking Red-throated Loon and the Yellow-billed and Pacific Loons.
Northern Saw-whet Owls
This small owl migrates south through Isle Royale in fall in larger numbers than those that actually breed on the island. Saw-whets roost in conifers during the day then hunt for insects and small mammals at night.
Kinglets
Both Golden-crowned Kinglets and Ruby-crowned Kinglets pass through the island’s forests during fall and spring migration en route between their boreal forest breeding grounds and more southern wintering areas.
Juncos
Dark-eyed Juncos, both slate-colored and Oregon races, occur in large migratory flocks passing through open areas and forest edges in spring and fall.
Waxwings
Bohemian Waxwings sporadically irrupt south in winter to occur in flocks on the island where they feed on fruit and berries. Cedar Waxwings also occasionally stop in during migration.
Crossbills
These odd finches use crossed mandibles to pry seeds out of conifer cones. Red Crossbills and White-winged Crossbills may appear in winter or migration when cone crops are abundant.
Snow Bunting
Large flocks of these snow-white birds stop to forage in open tundra and fields during migration. They breed in the high Arctic then winter farther south in Canada and the northern US.
Fox Sparrow
The Red Fox Sparrow migrates through the island’s forests in spring and fall but does not breed there in summer. Listen for its distinctive shuffling scratchings in the leaf litter.
Rare and Incidental Species
Due to its remote location in Lake Superior, Isle Royale also occasionally hosts some rare and accidental species well outside their normal range including:
Ivory Gull
This stunning all-white gull of the high Arctic has turned up very rarely on the island in winter.
Great Black Hawk
This tropical raptor caused great excitement when one took up residence on the island for several summers in the late 1990s and early 2000s, far north of its normal range.
American White Pelican
These large waterbirds normally breed no closer than Minnesota but stray individuals are spotted over Lake Superior each year with some pausing on Isle Royale briefly.
Say’s Phoebe
This insectivorous flycatcher of western North America has occurred a couple times on the island as a very lost vagrant.
Western Tanager
This brightly colored songbird was documented once on the island, far east of its normal range in western North America.
Conclusion
Isle Royale provides breeding habitat, wintering grounds, and migratory stopover sites for a remarkably diverse bird community. Over 200 species have been documented on this remote island in Lake Superior. The island’s geographic isolation and varied habitats ranging from boreal forest to Arctic-like ridges result in an interesting mix of northern specialty species, migrants, and year-round residents. Birders who make the trek to Isle Royale have a chance to see sought-after northern species like the Spruce Grouse, Boreal Chickadee, Gray Jay, Bohemian Waxwing, and Snowy Owl. The island also provides easy viewing opportunities for loons, mergansers, Bald Eagles, Yellow-bellied Sapsuckers and other more common northern forest birds. At any time of year, a visit to Isle Royale offers the chance to discover a diverse and exciting avian community.
| Season | Notable Bird Species on Isle Royale |
|---|---|
| Spring | Warblers, Flycatchers, Swainson’s Thrush, Common Loon, Osprey |
| Summer | Ovenbird, Common Raven, Veery, Bald Eagle, Ruby-throated Hummingbird |
| Fall | Shorebirds, Kinglets, Dark-eyed Junco, Hawks, Snow Bunting |
| Winter | Gray Jay, Boreal Chickadee, Pine Grosbeak, Snowy Owl, Rough-legged Hawk |
