A first-winter Common Tern (Sterna hirundo) (left) with a first-winter (right) and an adult winter (leftmost) Forster's Tern (Sterna forsteri) at the Port Aransas jetty, Nueces county, southern Texas on January 13, 2011:
The same first-winter Common Tern (right) with a first-winter Forster's Tern (left); compare the primaries, rump and tail patterns:
Another image of the first-winter Common Tern showing the upperwing pattern
