Scientific Name: Sterna hirundo
Population Estimate: 1.6M - 4.6M
Range: Breeds inland across the northern US and Canada. Winters along the coast in Mexico, Central America, and into northern South America.
Field Notes: Medium-sized, black-capped tern. Non-breeding plumage as above. Breeding plumage with orange bill and uniform black cap. Forster's Tern with black eye / ear mask in winter, and by brighter orange bill and legs in breeding plumage.
Personal Notes: We found this petite tern among the large gulls along the downtown beach in Puerto Vallarta.