Seagulls (Larus)
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Eighteen, or perhaps two-thirds of all North American seagulls belong to the Larus genus.
Adult identification can be straightforward. Most identification problems stem from the fact that juvenile gulls go through a series of molts prior to gaining what constitutes standard feathers for the particular adult species.
The four species presented here highlight within genera diversity.
The red bill of the Heermann's Gull (Larus heermanni), top picture, provides a great identification clue for this exclusively West Coast gull.
Often found on rocky coastal ledges, these hardy fish eaters forage their way as far north as British Columbia in search of a coastal oasis.
The Herring Gull (Larus argentatus), another very common Larus species, inhabits most North American shorelines.
Its summer range extends as far north as the south coast of Alaska and northern Canadian territories.
Pink legs and an orange to red mark on the bottom bill serve as the only real distinguishing marks of the species.
California Gulls (Larus californicus), the Utah State bird, share a common bill look, however adults have yellow legs.
Thayer's Gulls also share some physical features. A thick yellower bill along with yellow eyes, highlighted in picture three, provides a head shot comparison with the Thayer's Gull.
Yellow legs and a black ring around a yellow bill distinguish the Ring-billed Gull (Larus delawarensis) from other Larus species.
It's one of the more common North American gulls, wintering in the south from coast to coast. During breeding season, large flocks migrate as far north as southern Canada. The latin name delawarensis stands for the place the species was first recorded, the Delaware River.
Ring-billed gulls serve to remind us that sometimes the term sea gull is a misplaced description of the genus. Many individuals spend the majority of their summer and winter lives far away from salt water habitats.
The Thayer's Gull (Larus thayeri), picture five, an uncommon species, breeds in the high Arctic during the summer and winters along the West Coast, with a small Great Lakes winter population.
Often, but not always, Thayer's can be identified by brown eyes and comparatively more delicate looking bill. The bottom picture shows a close up of the Thayer's head to be used in comparison with the Herring Gull.
© 2006-2011 Patricia A. Michaels