Thayer's Gull (thayeri)

(last update: January 22, 2013)

Thayer's Gull adult July

Canadian Atlas of Bird Banding Volume 2: Seabirds, 1921–1995. (Gaston et al., 2008)

Thayer's Gull (Larus [glaucoides] thayeri) 43.1

Thayer’s Gull breeds on coastal sea cliffs from Ellesmere and eastern Baffin islands, west to Banks Island, and south to Vansittart Island and the north coast of Southampton Island (Gaston et al. 1986; Godfrey 1986). It winters along the Pacific coast from British Columbia to California (American Ornithologists’s Union 1998 and supplements through 2006). The status of Thayer’s Gull as a separate species is under some dispute. While Godfrey (1986) regarded it as a subspecies of the Iceland Gull (Larus glaucoides thayeri), the latest American Ornithologists’ Union checklist (American Ornithologists’ Union 1998) still maintains it as a separate species. However, until the 1960s, it was regarded as a subspecies of the Herring Gull (Larus argentatus). Consequently, earlier banding of thayeri was recorded as being of that species, and it is impossible to compile accurate banding statistics (hence, we have not included a summary table or banding effort map). Based on considerations of range, at least 59 thayeri have been banded in Canada. Thayer’s Gull is included here on the basis of one encounter near Vancouver of a bird banded near Cambridge Bay, Nunavut, where thayeri is known to occur, but argentatus does not (Parmelee et al. 1967). This encounter illustrates the typical wintering behaviour of the species and is noteworthy mainly for the speed of travel, which suggests that the bird may have travelled over land, rather than taking the very long sea route via the Bering Strait. Another bird banded as a Herring Gull at “Coppermine River,” Northern Territories, and encountered in California in winter could have been a Thayer’s Gull, but the banding locality does not match the coordinates given, which place it well inland; this encounter remains enigmatic.

Encounter records: Thayer's Gull (as per April 02 2012)

Age is nestling, bird incapable of sustained flight. "L" in current age codes.
Sex = U, unknown.

Number of birds banded in projects: