Gulls and Terns
GULLS
The term "Seagull" refers to a family of birds that are not truly birds of the sea. They really should be called "Shore-gulls" because only a few species (such as the Sabine's gull and Black-legged Kittiwake) ever venture any great distance from the shore. Since, however, Stellwagen Bank and Jeffrey's Ledge are so close to shore, a good number of Gull species can be seen on most whale watches to those areas. In my sixteen years working for 7 Seas Whale Watch I have identified eleven species of gulls from the decks of the Privateer or Privateer IV. Those species are: Great Black-backed Gull, Lesser Black-backed Gull, Herring Gull, Ring-billed Gull, Laughing Gull, Bonaparte's Gull, Black-headed Gull, Iceland Gull, Glaucous Gull, Sabine's Gull and Black-legged Kittiwake.
Herring and Great Black-backed gulls are by far the most common and are a familiar sight around the wharfs and piers of Gloucester harbor, although small numbers of Ring-billed and Laughing Gulls are usually present as well. Each year a good number of Bonaparte's Gulls are often seen feeding on small marine invertebrates around an area of the harbor called "The Fort" in late August and September. These little gulls (not to be confused with the species of gull called "Little Gull" which can sometimes be seen in Gloucester Harbor during the winter) are easily recognizable by their small size and bright white stripes on the leading edge of their wings.
Only two of the Gull species mentioned above are considered truly pelagic (or "ocean-going"): The Sabine's Gull and the Black-legged Kittiwake. The Sabine's Gull breeds in the far north along the shores of the Arctic ocean and is a very rare fall migrant through our area. Since 1983 I have heard of three Sabine's Gulls being seen from whale watch boats in the Jeffrey's Ledge/Stellwagen Bank area. I can personally vouch for two of those birds and the other one was reported from a very reliable source (that's your bird Peter!). There may well have been other sightings by experienced birders who often go on whale watches just for the birds but don't report their sightings. Sabine's Gulls can be recognized by small size (Length 13.5" Wing Span 33"), tern-like flight, and by the large white triangles on their upper wings. A really close look at a Sabine's reveals a black bill with a yellow tip. Juvenile Black-legged Kittiwakes can look very similar so be cautious before yelling "Sabine's!"
Unlike the rare Sabine's Gull, the Black-legged Kittiwake is quite common in our area. These gulls are actually winter residents in the Gulf of Maine that spend the summer breeding in Nova Scotia, Newfoundland and the Canadian high Arctic (a separate Pacific population breeds in Alaska). Watch for these birds in April and May and then again in September and October. They can be recognized by their wingtips which are purely black. Other Gulls such as Herring and Ring-billed Gulls have white spots in the black of the wingtips. The wingtips of the Kittiwake have been described as looking as if they were "dipped in ink".
TERNS
Terns, like gulls, are predominantly coastal birds. They are patterned much like gulls except they have a black "cap" during the breeding season and are generally much smaller and more delicate than gulls. Five species of Terns can be seen in our study area. The Common Tern is by far the most abundant. Common terns are about 12" in length with a wingspan of 13" and they have long, thin, blood-red bills with a black tip. Many common terns are misidentified as Arctic Terns which only migrate through the area in Spring and Fall. Arctic Terns have captivated the imagination of many birders because they hold the distinction of being the animal with the longest migration on Earth. Each year these birds migrate from their breeding grounds in the Arctic to their wintering grounds in the Antarctic 12,000 miles away. That means that they travel a total of 24,000 miles a year; a distance equal to circumnavigating the globe. All this with just a pea-sized ball of fat on their chest for energy! Arctic Terns can (with great care) be separated from the very similar Common Terns by their all red bill (no black tip) and by their slightly grayer bellies that give them a "white-cheeked" appearance.
Other Tern species seen from the Privateer or Privateer IV include Forster's, Caspian, Least, Black (rare), and Sooty (very rare, seen once in July of 1997).
