Lesser Black-backed Gull (us-RGV)
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Contents |
Regional Information
Range, Abundance, and Seasonal Variations
A vagrant to the Rio Grande Valley. Seen at S. Padre Island or Boca Chica Beach and the Brownsville landfill.
Directions and Maps
General Information
Size
Length: ??cm (??in), Wingspan: ??cm (??in)
Field Marks
Sexes similar. Large gull with slim bill with indistinct gonydeal angle. Round head. Adult breeding: Bright yellow bill with red spot at gonys, yellow legs and iris, white head, neck, breast, and belly, dark gray back and upperwings, white tertial crescent, black primaries with white tips and one or two white mirrors on outer primaries, white tail. Adult Non-breeding: Blurry brown streaking and spotting on head and nape. Juvenile/First year: Young birds have scaly black-brown upperparts and a neat wing pattern. They take four years to reach maturity. Identification from juvenile Herring Gulls is most readily done by the more solidly dark (unbarred) tertial feathers.
Black bill, wholly brown body plumage but may be paler on head, back appears somewhat checkered, dark brown primaries, dark brown secondaries and secondary coverts, pinkish legs, dark outer primaries, pale rump marked with dark bars and appears pale, dark tail. Second year: Variably pinkish bill with black tip, pale brown head, neck, upper breast, and belly, dull brown upperwing coverts, dark brown primaries and tail, dark gray back, white tail with black terminal band. Third year: Like adult basic, but often lacks adult bill pattern, wing pattern, and often retains a partial tail band
Similar species
From the second year through adult plumage, the Lesser Black-backed Gull has a very dark gray back. Great Black-backed Gull has wingtips the same color as the mantle, not darker as the Lesser, and pink legs. Western and Slaty-backed Gulls are larger and have pink legs. Yellow-footed Gull is larger with a darker back, larger bill, and a restricted range. First-year Lesser Black-backed Gulls are very similar to Herring Gulls but have whiter rumps, darker wing coverts, entirely black bills through their first summer, and paler heads and underparts that are spotted with brown. First-year Great Black-backed Gulls have whiter heads and are larger with much bigger bills, and have more strongly checkered wing coverts and secondaries.
Sounds
The call is a "laughing" cry like that of the Herring Gull (to which this species is closely related), but with a markedly deeper pitch.
Feeding & Behavior
They are omnivores like most Larus gulls, and they will scavenge as well as seeking suitable small prey.
Habitat & Nesting
Breeds colonially on coasts and lakes, making a lined nest on the ground or cliff. Normally, three eggs are laid.
Range
Breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa. It is also a regular winter visitor to the east coast of North America, probably from the breeding population in Iceland.
Resources
