Guide to Stellwagen Sanctuary Birds

The northern gannet’s staring
The northern gannet’s excellent eyesight is important in its search for food. Photo: Peter Flood

Stellwagen Bank National Marine Sanctuary attracts seabirds year round. Summer visitors may fly long distances to indulge in the smorgasbord of the bank’s resources, while winter visitors seek to escape the colder climes of northern islands and rocky coasts. Mid-season migrants stop by to bulk up in preparation for the last legs of their travels. Here’s a review of some of our avian visitors. The seabirds’ average adult size (measured from bill tip to tail tip) is noted along with their identifying characteristics when in the sanctuary (plumage colors sometimes vary greatly over the year and with age).

Stellwagen Bank's Birds of Summer

The following species are among the more commonly seen birds during the summer months, they may occasionally be spotted during the shoulder seasons of spring and fall. Some species are even seen year round. Many birds migrate to this area from more southern areas, where they breed during our winter and a subset of this group are global travelers, using the rich marine resources to bulk up for the very long commute to the Southern Hemisphere.

Hover over the images to reveal facts about the Stellwagen Bank's Birds.


Most gulls are opportunistic feeders, meaning that they will practically eat whatever is easiest to get, such as fish and shellfish, but often also consume garbage or the eggs and chicks of other species. Gulls also regularly follow fishing boats to gorge themselves on fish wastes thrown overboard. Gulls have many confusing immature plumages and some species do not reach their adult plumage until they are roughly four years old. Commonly seen gulls in the sanctuary are herring, great black-backed, and laughing gulls. Of these birds, the laughing gull is the only species to migrate to warmer climes in the winter.

Herring Gull (25 inches)

Photo: Peter Food

This is the gull that is most often referred to as a “seagull.” It is the most common gull in Massachusetts throughout the year. Young herring gulls are mottled brown, but adults have a pale gray back, black wingtips with white spots, pink legs and feet, and a red spot on a yellow bill. Herring gulls are year-round residents in the sanctuary region and compete with other gulls and terns for nesting sites.

Great Black-backed Gull (30 inches)

Photo: Peter Food

The largest gull species in the world, this once scarce species in Massachusetts is now a common sight in the sanctuary throughout the year. Open garbage dumps and landfills in past years provided many dining opportunities. This big bully harasses other seabirds to steal their catches and preys on smaller birds and eggs. This is one of the most distinctive gulls, with a large yellow bill with a red spot, and a black back and wings which contrast sharply with its snow-white head and undersides.

Laughing Gull (17 inches)

Photo: Peter Food

This gull is regularly seen in the sanctuary, and like the herring and great black-backed gull, it nests in coastal New England. Unlike the other two species it migrates south for the winter.It has a call that resembles raucous laughter. A bit smaller than the herring gull, the laughing gull has a black head in summer (which turns white in winter), white arcs around its eyes, a red bill, and black or red-black legs. Laughing gulls have medium-dark gray wings and are white below.


Terns are streamlined and agile seabirds, smaller than gulls, with pointed wings, sharp bills, and deeply forked tails. They catch small fish by hovering, beak pointed down, then plunging into the water. There are a number of species of terns, but only a few are regularly seen in the sanctuary, frequently on their way to and from shore after fishing trips for sand lance. Most of the sanctuary’s terns -- common, least, and roseate, are summer birds. The Arctic tern stops in during a long-distance migration (see shoulder season birds for this species.)

Common Tern (12 inches)

Photo: Peter Food

This tern breeds along the Massachusetts coast, has a black cap, and a bright red-orange bill with a dark tip. It is light gray across its back and wings. Most of these birds winter in South America.

Roseate Tern (13 inches)

Photo: Peter Food

Listed as endangered, the roseate tern resembles the common tern but has a dark (almost black) bill, longer tail points, and is paler white above. It can also be identified by its distinctive squeaky or sometimes raspy call that sounds like ripping cloth. It winters from the West Indies to Brazil.

Least Tern (9 inches)

Photo: Peter Food

This tern is much smaller than the others, and has much quicker wingbeats. It has a yellow bill and feet and a white forehead. It winters off the coasts of Brazil, and is most common in more southern waters.

Storm Petrels

These small, dark seabirds flutter erratically over the top of the waves or patter on the surface with their feet while feeding on plankton. The name petrel refers to St. Peter and because they appear to walk on water, local residents sometimes refer to them as "Jesus birds.” Storm petrels rarely come to shore except when pushed by storms, yet they are considered to be among the most abundant birds in the world. Storm-petrels belong to a group of seabirds called “tubenoses” because of the tubular nasal passages on their bills.

Wilson's Storm-Petrel (7 inches)

Photo: Peter Food

This long-distance migrant breeds in Antarctica and ranges north to temperate and subarctic areas of the Northern Hemisphere during our summer. It is a small, sooty-brown seabird, with pale wings and a conspicuous white patch on its rump. Its tail is rounded at the end without a fork. It is often seen following fishing boats for discarded fish and offal, and can pick at carrion.

Leach's Storm-Petrel (8 inches)

Photo: Peter Food

This bird stays in the Northern Hemisphere in the summer and spends the winter in tropical and equatorial waters. The Leach’s storm-petrel has a forked tail. It is also a bit more brown and has a more V-shaped rump patch than a Wilson’s. Its longer, more angled wings have a pale band on the upper surface. Unlike the Wilson’s storm-petrel, this bird does not follow ships.


Shearwaters are narrow-winged, gull-like birds that glide low over the water, appearing to “shear” the tops of waves in search of small fish, squid, and crustaceans, as well as garbage from ships. Although they can be very noisy at their nesting sites, they are usually silent at sea. Four species of shearwaters are seen in the sanctuary. Like the storm-petrels, they are referred to as “tubenoses” because of the tubular nasal passages on their bills.

Great Shearwater (18 inches)

Photo: Peter Food

This bird is dark above and white below, with a black cap, white cheeks, and a pale collar on the back of its neck. It also has a white horseshoe-shaped tail patch and a dark smudge on its belly. Like several other summer visitors, great shearwaters undertake long migrations. Their breeding ground is the Tristan da Cunha Islands in the South Atlantic. These seabirds are the subjects of a multi-year study of distribution and ecosystem health in the sanctuary.

Sooty Shearwater (17 inches)

Photo: Peter Food

This bird is charcoal gray with grayish-white wing linings. It is slightly smaller than the great shearwater. The light gray shade on the underside of the wings provides a silvery flash during flight. Like the great shearwater, the sooty migrates to the Southern Hemisphere, nesting off the coast of southern South America.

Manx Shearwater (13 inches)

Photo: Peter Food

This shearwater is both the smallest and the least common shearwater in the sanctuary. It is dark above from head to tail, is pure white below all the way to its under tail, and, unlike the great shearwater, does not have a white rump patch. Its migration is not well understood.

Cory’s Shearwater (19 inches)

Photo: Peter Food

The largest of the local shearwaters, the Cory’s shearwater generally has slower wingbeats than its cousins, and it often exhibits prolonged glides. The brown head and white throat are not as distinct as the dark cap on the great shearwater, its underparts are pure white, and its yellow bill differs from the darker bills of the other shearwaters.

Jaegers and Skuas

Jaegers are the pirates of the seabird world, and are often called "robber gulls." Falcon-like in shape, jaegers pursue gulls and terns for their food, forcing their hapless victims to drop or disgorge their food, and then steal it. Jaegers have dark and light forms, with subadults exhibiting a confusing array of plumages. The south polar skua is another rarer predatory seabird in the sanctuary that also steals food from other birds or catches fish on its own.

Parasitic Jaeger (18 inches)

Photo: Peter Food

This bird's elongated and pointed central tail feathers stick out 1-3 inches beyond the rest of the tail and end in sharp points. The bird has a slightly hooked beak and shows a flash of white near the end of its wings in flight.

Pomarine Jaeger (22 inches)

Photo: Peter Food

Larger and heavier than the parasitic jaeger, the pomarine's tail feathers are also broader and twisted, not pointed. It also has a slightly hooked beak, and in its light form is more heavily barred, including dark along the sides of its belly.

South Polar Skua (21 inches)

Photo: Peter Food

The south polar skua nests in the Antarctic, then travels northward to arrive off New England in early summer. Like the jaegers, it pirates food from other seabirds after harassing and sometimes physically attacking them. Overall coloring is dark gray-brown with conspicuous white wing flashes observable in flight. There is also a pale form with a light-colored head and pale underparts. The bird is bulkier than the jaegers.


Cormorants have slender, hooked-tipped beaks, long necks, elongated black bodies, and are often seen in a distinctive "spread-eagle" pose as they air-dry while sitting on moorings, pilings, and shore-side power lines. These birds are underwater-pursuit swimmers that predominantly feed on fish. The double-crested cormorant is a regular summer visitor, while great cormorants come to these waters in late fall and winter.

Double-Crested Cormorant (33 inches)

Photo: Peter Food

These cormorants are among the most commonly seen shore-based birds when leaving port to head out to the sanctuary. They are black with a metallic-sheen, a yellow-orange throat, and green eyes. Cormorants are among the larger birds in the sanctuary.

Stellwagen Bank’s Birds of Winter

Many winter seabirds on Stellwagen Bank have a similar look – mostly black and white. For identification purposes, look for subtle differences in body shape and bill size. The birds generally visit the sanctuary between November and March after having migrated south from colder areas in the far north.


Alcids are a group of stocky, black-and-white seabirds. They are the Northern Hemisphere's equivalent of penguins, and although they resemble miniature penguins, the two groups are not closely related. A now extinct alcid, the flightless great auk, Pinguinus impennis, was actually called a penguin long before the Southern Hemisphere penguins were first described. Like penguins, alcids walk upright with their legs set near the back of the body, making them waddle clumsily on land. In flight they resemble small footballs with wings, but in the water they are agile swimmers and prodigious divers, using their wings to pursue small fish and crustaceans. Alcids nest in dense colonies along the rocky coasts and islands of northern Maine and North Atlantic and Arctic Canada.

Razorbill (16 inches)

Photo: Peter Food

The razorbill is black above and white below with a pointed tail that is often angled upwards when swimming. It has a thick, laterally compressed bill, and a body that appears somewhat hunchbacked in flight. The head is black on top in winter with a white throat and a vertical white band running across the middle of the bill. In flight, razorbills show a white trailing edge on the wings and white on either side of their black tail. Similar in size to a common murre.

Thick-Billed Murre (17 inches)

Photo: Peter Food

The thick-billed murre is black above and white below, and often displays a dusky throat and lower face in winter. Its solid black hood extends to below its eyes. The bill is shorter and thicker than that of the common murre and it has a thin whitish line at the gape. Although murres have stocky bodies, in flight they appear more streamlined and thinner-necked than razorbills. They are similar in size to the common murre.

Common Murre (16 inches)

Photo: Peter Food

The common murre is black on top and white below with a white throat and cheeks in the winter. Unlike the similarly sized thick-billed murre, it has a dark stripe extending back from its eyes into the larger white cheek/neck area, has a longer and more slender bill, and often has a brown-colored back.

Dovekie (8-9 inches)

Photo: Peter Food

Dovekies are small, chubby alcids that feed on planktonic crustaceans. Like all alcids, dovekies are black above and white below. However, their small size, short necks, and stubby beaks make them easy to distinguish from other species, both in the water and in flight. Non-breeding birds have white throats and a white ear patch.

Atlantic Puffin (12 inches)

Photo: Peter Food

The Atlantic puffin is a chunky, black and white alcid with white cheeks and a large triangular, tricolored bill. Puffins are slightly larger than dovekies. In winter, Atlantic puffins’ bills are smaller and less colorful, but still maintain a triangular shape, and their white cheeks turn gray. In flight, puffins can be identified by their rounded, solid black wings, bright orange feet, and big-headed appearance.

Black Guillemot (13 inches)

Photo: Peter Food

The black guillemot is a slender, somewhat duck-like alcid with a pointed bill, and short, pointed wings with a large white patch on the top. Guillemots are more commonly seen close to shore than other alcids. In breeding plumage they are all black except for the white wing patch. In winter they show a mottled black and white pattern on the wings, and a white head, neck, and underparts. Guillemots have a thin, straight, pointed, black bill and bright red legs and feet.


There is never a shortage of gulls over Stellwagen Bank, and winter is no exception. Black-legged kittiwakes are the most common winter gull (and are a truly pelagic bird). Year-round gull residents include herring and great black-backed gulls.

Black-Legged Kittiwake (17 inches)

Photo: Peter Food

Black-legged kittiwakes, which feed on small fish such as sand lance, can be abundant over Stellwagen Bank during the winter. These primarily white birds have gray wings, pure black wingtips that look as if they had been dipped in ink, an unmarked yellow bill, and short black legs. In winter, they have a dark gray smudgy spot behind each eye. Juveniles are white with a black M-shaped pattern on the upper side of the wings.

Bonaparte’s Gull (14 inches)

Photo: Peter Food

Breeding Bonaparte’s gulls have heads that look like they were dunked in black ink and pink legs. In winter, birds in the sanctuary have gray wings with white primary feathers that are white all the way to the outer edge of the wings and are neatly trimmed in black, along with pink legs, and a gray spot on each cheek. This is a small, swift-moving, tern-like gull.

Iceland Gull (20-23 inches)

Photo: Peter Food

These gulls have white wingtips, lacking the extensive black tips of herring gulls. They are light gray above with white underparts, pink legs, and yellow bills (shorter and more slender than herring gulls) with an orange spot. They often follow fishing boats. Their head and neck may have a brown smudgy appearance in winter. A larger bird, the less commonly seen glaucous gull, has very similar characteristics.

Sea Ducks

Sea ducks generally stay close to shore and rarely spend extended periods of time in sanctuary waters. The males are usually larger than females. Males and females display distinctly different plumages with the males typically showing darker coloring with patches of white and color on their bill or legs. The females’ plumages are primarily brownish. Sea ducks often gather in very large flocks of mixed species. The common eider is the largest sea duck in the sanctuary.

Common Eider (20-28 inches)

Photo: Peter Food

This bird, the largest Northern Hemisphere sea duck, winters in huge numbers on the shoals off Cape Cod and the islands, but is also often found close to shore. In Massachusetts, they commonly breed in Boston Harbor and in Buzzards Bay. Breeding males are white with a black cap, black bellies, and green coloring on the nape of the neck; nonbreeding males seen in the sanctuary are brown, usually with some white on the breast. Females are rusty brown with black barring on their plumage.

Black Scoter (17-19 inches)

Photo: Peter Food

The black scoter is a medium-sized sea duck. Males are completely black with a rounded yellow knob at the base of the bill; females are brown with a buff-colored face and a dark cap, and lack the yellow bill knob. A similar species is the slightly larger surf scoter. Males can be identified by white patches on their nape and front of their head, and an orange-white-black bill; females are brownish, with two or three pale patches on their face.

White-winged Scoter (19-22 inches)

Photo: Peter Food

Male white-winged scoters are deep black with large white patches on their wings and a relatively small comma-shaped white mark that curves up and back from under the eye. They also have a thick neck, a large head, and an orange bill and legs. Females have a darker bill, a brown body, and two rounded white patches on each side of the head. The female surf scoter is similar except it lacks the white wing patches.

Long-Tailed Duck (15-18 inches)

Photo: Peter Food

The male long-tailed duck has long, slender tail feathers, the female does not. These small active sea ducks have rounded heads and small dark bills. In the winter, males have a dark patch on the neck with a white head, and a pink band on the bill. The female’s body is brownish with a white head and a brown cheek patch.

Other Winter Species

Several other common species winter in the sanctuary The great cormorant is a visitor after the double-crested cormorant leaves and can gather in flocks, but in fewer numbers than its cousin. Individual sightings of common loons may be difficult to see due to the muted colors of their winter plumage, but are not uncommon in the sanctuary. Both cormorants and loons sit low in the water and dive from the surface for fish.

Great Cormorant (36 inches)

Photo: Peter Food

The great cormorant is slightly larger and chunkier than its double-crested cousin. They also have white feathers on their throat, and adults display white patches on their flanks in late winter and spring.

Common Loon (32 inches)

Photo: Peter Food

The common loon is easily recognized in its breeding plumage (black head, black and white checkerboard back, shiny green or blue neck band, and striped collar) and a distinctive wailing call. It spends summers on quiet inland lakes, and most loons move to coastal ocean waters in winter. In winter the loon’s appearance is muted with a brownish-gray head and back, and white underparts and a white lower face and neck.

Shoulder Season Birds

These birds can be seen spring and fall on their way to and from breeding and feeding grounds. Some may stick around for extended periods of time. When in the sanctuary, these seabirds display various patterns of black and white plumage.

Arctic Tern (12 inches)

Photo: Peter Food

Arctic terns are only occasionally seen flying over the sanctuary. They have a bright, blood-red bill all the way to the tip, and their breast is grayer than that of the common tern. The Arctic tern also has shorter legs and is more common in northern waters. This marathon migrator breeds in Arctic areas and then winters in Antarctica, traveling some 25,000 miles.

Northern Gannet (36-43 inches)

Photo: Peter Food

The northern gannet is the largest seabird in the North Atlantic, and adults are predominantly white in color with black wingtips, and a yellowish wash on their heads. They have large pointed bills, and pointed tails. Juveniles are variously molted with brown and white, and they take several years to acquire the white plumage of adults. Gannets catch fish by hovering 80 feet or more above the ocean, then plummeting head first into the water in pursuit of their prey.

Northern Fulmar (17 inches)

Photo: Peter Food

The northern fulmar is a stocky seabird with a thick neck and nostril tubes on its bill. Although it resembles a gull, it is more closely related to shearwaters and petrels. It uses stiff wingbeats to create a less than graceful flying style. Northern fulmars vary in color from white with gray wings and darker gray wingtips (light form) to an overall dark gray color (dark form). They are opportunistic feeders and readily follow working fishing boats in search of food.

Red-Necked (7-8 inches) and Red (8-9 inches) Phalaropes

Photo: Peter Food

These curious sandpipers breed in the Arctic and sub-Arctic tundra but spend most of their lives at sea. Flocks migrate through the sanctuary during spring and early fall. Their dense plumage traps large amounts of air, which makes them ride high in the water, like corks bobbing at sea. They often spin in place, stabbing the water with needle-like beaks for copepods and other zooplankton. Females are larger and have a more brightly colored summer plumage than the males (reddish underparts from neck to tail in the red, a red neck patch in the red-necked). When seen in the sanctuary during the non-breeding shoulder seasons, their plumage is primarily white and black, and their bills are black. The smaller red-necked phalarope is the more common of the two species.