Birds of Ocracoke Series

Birds of Ocracoke: The Great Black-backed Gull

Great Black backed Gull PS IMG_4996

To see more profiles in the Birds of Ocracoke series, click here 

(Larus marinus)

Text and photos by Peter Vankevich

This species is considered to be the largest gull in the world.  The adult plumage,  achieved in its fourth year (both sexes similar), has a black mantle, white head and undersides, a thick yellow bill with a red spot on the lower mandible and light pinkish legs. Subadults are very large with a whitish head and underparts, barred or checkered back and wings, and a large,thick black bill.

subadult Great Black-backed Gull

Subadult Great Black-backed Gull

They nest on rocky outcrops, grassy knolls and barrier island dunes.

This bird is a scavenger and will eat most anything including  crabs, sea urchins, other marine invertebrates, garbage, fish and smaller birds. At landfills, they eat rats. It is a threat to colonial birds such as terns since it will eat eggs and chicks.  Management officials control the breeding of Great Black-backed Gull populations and their presence on some islands to give terns, puffins and other species a chance to nest and fledge young successfully.

This bird has expanded its range in the last 100 years or so (see below). Primarily a coastal bird in North Carolina, it is increasingly being seen throughout the state.

Generally silent when on Ocracoke.

Listen :

(audio provided courtesy of OhioLINK Digital Resource Commons)

When to see: Possible year around, though relatively few in summer. Abundant by mid-fall till early spring.

Where: Both Ocracoke and Hatteras inlets, dredge spoil islands, beach, ocean, sound and Silver Lake Harbor

Click here for the Birds of the Outer Banks checklist

Notes 

Great black-backed lesser black-backed gull PS 09.34.12

Lesser Black-backed Gull in forefront, Great Black-back Gull behind it.

A similar appearing species that appears on Ocracoke, particularly in the fall, is the Lesser Black-backed Gull which has a lighter mantle and streakier head. It is also much smaller and slimmer, has a thinner bill and yellow rather than pinkish legs.

Prior to the 20th century, in North America its primary nesting areas were the coasts and islands of the Canadian Maritime provinces.

Nearly extirpated by feather hunters and egg collectors in North America during the 19th century, where it was found primarily in Northeastern Canada, it rebounded when protection measures were enforced.

Unlike the 20th century trend of many land birds whose nesting ranges have been moving north as their populations started to increase, the Great Black-backed Gull’s nest­ing range began to expand south–first to Maine (1928), then to Massachusetts (1931), New York (1942)  and eventually onward to coastal Virginia and North Caro­lina (1970).  Garbage dumps and human refuse probably are major reasons for its expansion.

Historically, Great Black-backed Gulls were also generally nonmigratory, except for their northern-most breeding areas. Thus, when in the evening of Feb. 27, 1934, six of these birds were seen near Ocracoke, it was of such significance that it was reported in the vener­able ornithological journal, The Auk.

Gulls, including this species, wintered in great numbers on Ocracoke during the 1980s. Their numbers have decreased, though many are still present.

On a personal note, when I became a hard-core novice birder, I spotted one from a distance on Chincoteague Island and thought I had spotted my first Bald Eagle.  A view through binoculars dispelled my enthusiasm.