979-1940 - Heermann's Gull (Larus heermanni) mating ritual on their breeding grounds on Isla Rasa in the middle Gulf of California (Sea of Cortez), Mexico
979-1942 - Heermann's Gull (Larus heermanni) mating ritual on their breeding grounds on Isla Rasa in the middle Gulf of California (Sea of Cortez), Mexico
979-1938 - Heermann's Gull (Larus heermanni) eggs laid on their breeding grounds on Isla Rasa in the middle Gulf of California (Sea of Cortez), Mexico
979-1945 - Adult Heermann's Gull (Larus heermanni) in flight on their breeding grounds on Isla Rasa in the middle Gulf of California (Sea of Cortez), Mexico
979-1939 - Heermann's Gull (Larus heermanni) mating ritual on their breeding grounds on Isla Rasa in the middle Gulf of California (Sea of Cortez), Mexico
979-1941 - Heermann's Gull (Larus heermanni) mating ritual on their breeding grounds on Isla Rasa in the middle Gulf of California (Sea of Cortez), Mexico