Heermann's Gull

Heermann's gull is one of the more distinctive and beautiful gulls. We saw them recently along the rocky coast at Puerto Penasco, Sonora, Mexico, at the northern end of the Gulf of California. 

A large group in the rocks along the coast. 

Flying near the restaurant we were eating at.

It has a medium gray body, blackish-gray wings, a tail with white edges, black feet and legs, and a red bill with a black tip. In breeding season the head is white, and in non-breeding season the head is dusky gray. Immature birds have flesh-colored or pink bills and are darker and browner than non-breeding adults. 

Beautiful, beautiful bird.

Distinctive red bill with black tip, and this one has a red ring around the eye. I assume that may be a breeding phenomenon. 

Even the inside of the bill is red. 

There are about 90,000 breeding pairs and 90% of them nest on the island of Isla Rasa in the Gulf of California, east of Baja California about the same latitude as Hermosillo. After breeding they will usually go as far north as central California, although they occasionally get as far north as British Columbia, and as far south as Guatemala. 

Front view of bill.

The IUCN rates it as "near threatened."