Heermann's Gull
Larus heermanni
This species looks distinctly different from other gulls. Adults have a medium gray body, blackish-gray wings and tail with white edges, and a red bill with a black tip. The head is dusky gray in non-breeding plumage and white in breeding plumage. Immatures resemble non-breeding adults but are darker and browner, and the bill is pink till the second winter. A few birds, no more than 1 in 200, have white primary coverts, which form a showy spot on the upper wing.
ID text from Wikipedia, CC BY-SA 4.0
Kelp Gull
Larus dominicanus
The kelp gull superficially resembles two gulls from further north in the Atlantic Ocean, the lesser black-backed gull and the great black-backed gull, and is intermediate in size between these two species. This species ranges from 54 to 65 cm (21 to 26 in) in total length, from 128 to 142 cm (50 to 56 in) in wingspan and from 540 to 1,390 g (1.19 to 3.06 lb) in weight. Adult males and females weigh on average 1,000 g (2.2 lb) and 900 g (2.0 lb) respectively. Among standard measurements, the wing chord is 37.3 to 44.8 cm (14.7 to 17.6 in), the bill is 4.4 to 5.9 cm (1.7 to 2.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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