Common Gull Page 3

St. John's Newfoundland

Adult winter Common Gull (Larus canus canus) on 14 January 2007 at the St. John's dump.

This adult Common Gull differs from Mew Gull (L.c. brachyrhynchus) by ring on bill. Note also wider white tertial crescent which is narrow on Ring-billed Gull. Its mantle was one shade darker than Ring-billed, but not as dark as Mew Gull. St. John's dump on 14 January 2007

Two large white mirrors on outer primaries 9-10. Note different black and white wingtip pattern than on Mew Gull which usually has less black on wingtips and white tongue tips on primaries 6-8. 14 January 2007

Second winter Common Gull. Appears much like an adult but lacks white tipped primaries, tertial crescent less obvious and bill somewhat duller. Note adult-like gray wing coverts which are brownish and contrast with scapulars in same age Mew Gull. Quidi Vidi Lake in St. John's on 17 January 2007.

Second winter Common Gull (same bird as above). In flight showed two large mirrors as on adults and more black in wingtips, and it had dark markings on the primary wing coverts unlike adults. Also note absence of dark tail band present in same age Mew Gull.

Adult-like appearance of second winter Common Gull. Two white mirrors and no dark tail band. Same bird as two above.

First winter Common Gull. Note gray adult-like scapulars typical of a three year gull in first winter plumage and neatly trimmed wing coverts compared to same age Ring-billed Gull. Note also somewhat different bill color and black tip. 15 January 2007.