Although ubiquitous where ever we turn, I was curious about the several different species that are often observed fishing and feeding together at dawn. The flocks of seagulls that we see on Cape Ann at this time of year are typically comprised of two species and they are the Great Black-backed Gull and the Herring Gull. In the above photo taken at daybreak (click to view larger), you can see both species; the gulls with speckled feather patterns are first year fledglings of both the Great Black-backed and Herring Gulls.
Interestingly, early in the twentieth century, both species of gulls were mostly winter visitors, neither staying to breed when the weather warmed. The first pair of breeding Herring Gulls was discovered on Martha’s Vineyard in 1912. The first pair of breeding Great Black-backed Gulls was found in Salem in 1932.
The Great Black-backed Gull (Larus marinus) is the larger of the two, up to 30,” with a black back and wings, yellow bill distinguished by a red dot on the bottom near the tip, and pinkish legs.
The Herring Gull (Larus argentus), at 25 inches, has gray wings tipped with black, gray back, white head, pinkish legs, and yellow bill also with a red dot on the bottom near the tip.
The Ring-billed Gull (Larus delawarensis) is also a regular visitor but according to Mass Audubon, it has never successfully bred in Massachusetts. The Ring-billed at first glance looks similar to the Herring Gull but is the smallest of the three at 17″ and is also easy to distinguish as it has yellow legs and a dark gray band near the tip of its bill.