This presumed Great Black-backed Gull (Larus marinus) was
photographed in northern coastal Tamaulipas, Mexico on November
26 1998 by John Gee and Carol Edwards. The bare parts strongly
indicate a 3rd-Basic age yet the plumage strongly indicates a
2nd-Basic age - so what age is it? This may be the first GBBG
for Mexico, so I would appreciate helpful comment - thank you.
comparison to a herring gull:
