Telling One Good Tern From Another
I think it is very difficult to ID shorebirds. Many shorebirds species look almost identical, with only minute variations in size or coloring. In many species, appearance changes dramatically as they age, and some species even look different during different months of the year! The tern species we see around here are very confusing. There were two species of terns at South Beach the day we went: Common Terns and Roseate Terns. During spring and summer, adult Roseate Terns can usually be identified by their thin black bills (as opposed to the orange and black bills of Common Terns). But not always.
This bird's bill looks very black, but since it is immature, a black beak is meaningless. Both species have dark bills when immature or non-breeding. Mature birds have solid black caps, but this bird has a white forehead. This bird has been banded, but that is no help to me.
The white forehead looks rather un-ternlike, but virtually all terns have a white topped head more often than not.
The dark band on the shoulders is something I associate with Common Terns, but . . .
this is also a juvenile bird, so who knows?
The best bet is to say they're all Common Terns, and let it go at that!