Acadia boasts a wide variety of shorebirds adapted to rock coasts, mudflats, and sandy beaches. Although many migrate for the winter, some can be seen year round.
Herring gulls feeding, juvenile is in between the two lighter colored adults.
NPS Photo by Nicole Ball
Gulls
Gulls are perhaps the most commonly seen, yet most overlooked, shorebird at Acadia National Park. Two species that can be found at Acadia are the herring gull and the great black-backed gull. They can be distinguished by the great black-backed gulls' darker color and its size: great black-backed gulls are the largest member of the gull family.
Although most commonly seen by the shore, these inquisitive and adaptable birds can be found throughout Mount Desert Island, even as far up as Cadillac Mountain's peak. Gulls are social and employ a wide variety of calls and cries to communicate. Their natural diet consists of fish and marine invertebrates, and have been observed dropping hard shelled prey from great heights to crack it open. Gull pairs form in the spring, with both parents contributing to hatching and raising the chick over the ensuing six months. While some gulls are independent and will leave their mate after the chick reaches maturity, others keep a close eye on each other year-round.
Some gulls at Acadia display bands on their legs. Banded birds wear one metal band, containing an ID number unique to that individual, and one colored band, which indicates where the bird was banded. Gulls banded at Acadia have either red and black or orange and white colored bands. These bands help researchers track population patterns. Although gulls are adaptable opportunists, their numbers have been declining in some areas. Report banded gulls, as well as time, date, and location when possible. Research of these birds may help them, as well as other shorebirds, in the future.
Least sandpiper foraging
NPS Photo by Nicole Ball
Sandpipers
Sandpipers are very small shorebirds that can be found at mudflats, where they forage for food and nest. Their diet consists of crustaceans, insects, and snails, which they locate either by site or by probing with their long, narrow beaks. Acadia is home to several sandpiper species, including the yellowlegs, purple sandpiper, spotted sandpiper, and more. The least sandpiper, a species found at Acadia, is considered the smallest shorebird.
Sandpipers create shallow nests near their feeding grounds. Both parents incubate the eggs. In some species of sandpipers, including spotted sandpipers and least sandpipers, the male takes a more active role in raising the young whereas the females create and protect the territory. Young sandpipers are able to feed themselves and fly within two weeks of hatching. Sandpipers are among the species that leave Acadia and migrate south for the winter.
Plovers and least sandpipers at Fraiser Point.
NPS Photo by Nicole Ball
Plovers
Plovers are small shorebirds that forage at mudflats and tidal pools by sight. Their diet includes crustaceans, mollusks, and insects. Although most easily seen at Acadia by the shore, some species, such as the killdeer, named after its cry, can be seen further inland at fields and riverbeds.
Plovers nest on the ground in open areas, where their young may be susceptible to predators. As a defense, adult plovers will fool predators by mimicking a broken wing, luring the predator from the nest, then flying away once the predator is sufficiently far enough away.
Double-crested cormorant in surf near rocks at Schoodic Point
NPS Photo by Nicole Ball
Cormorants
Cormorants are medium-to-large dark-colored shorebirds that can be found on rocky coasts and in the water. Double-crested cormorants and great cormorants can both be found at Acadia.
They are talented divers, frequently seen plunging below the surf to hunt for fish. When not swimming, they are frequently seen sunning themselves with wings spread. There is debate as to whether or not cormorant feathers are waterproof, water permeable, or only partially waterproof. Cormorants also have dense bones- a trait shared by loons, to aid in diving.
These gregarious birds often aggregate by the water, where they create nests of flotsam, seaweed, and often human waste such as plastic. Cormorants lay 3 to 4 eggs, which they incubate by holding on their feet. Young cormorants are born helpless and rely on both parents for food and water. Once they become more independent they may congregate with other young birds rather than stay in their nests.
Great blue heron with a tiny catch in its mouth
NPS Photo by Nicole Ball
Herons
Great blue herons are one of the largest shorebirds inhabiting Acadia, recognizable by their size and distinct body shape. They generally breed in colonies, called “rookeries,” close to wetlands. Trees, islands, or other hard to reach places are preferred for nesting. These nests are sometimes shared with smaller herons, and rarely, even mammal-eating raptors.
Fish are the primary food for great blue herons, but they may also prey on amphibians, snakes, and even small mammals. Herons locate food by sight and swallow it whole.
Egrets and bitterns may also be found at Acadia.
Breeding adult black guillemot off Schoodic Point
NPS Photo by Nicole Ball
Guillemots
The black guillemot is a medium-sized seabird with mostly black feathers and distinctive red feet and inner beaks. They dive for their preferred prey- crustaceans and fish. Mollusks, insects, and some plant material also make up their diet. Guillemots utilize rocky cliffs, crevices, and boulders for their nests. Breeding pairs will either remain solitary or in a small group, generally raising two chicks.
Eiders; immature male top center
NPS Photo by Nicole Ball
Eiders
The common eider is one of the largest ducks in North America, second only to the Muscovy duck. Its range extends beyond Acadia. It can be found as far out as Europe and Siberia, even traveling to the Arctic where it breeds. Females are mottled brown whereas adult breeding males are black and white. Eiders line their nests with down from the female's breast. Historically, this down has been collected by humans after chicks hatch and used in winter clothing and bedding.
A group of common terns hover and dive above a school of fish.
Will Greene / Friends of Acadia
Terns
Terns are medium-to-small shorebirds closely related to gulls, but can be distinguished by their relative smaller size, narrower wings, and forked tails. Non-breeding individuals may have white on their heads, whereas breeding adults maintain a fully black cap. This species is migratory and has a large range, extending well outside of Maine to temperate regions of Europe, Asia, and the rest of North America. They create shallow nests close to the shore and both parents incubate the eggs. Their diet consists of fish, which they catch by plunge-diving, as well as invertebrate prey.
Common terns form breeding colonies with up to two thousand mated pairs. The male primarily defends the territory from other adults of both sexes. However, chicks are generally allowed to wander. Most birds will return to the same territory year after year.
Other Shorebirds
Acadia hosts a wide variety of other shorebirds. Puffins nest on offshore islands, but are too far out to be seen from Mount Desert Island. Check with area Chambers of Commerce for boating companies that travel to these islands.
