Mystery Bird: Forster's Tern, Sterna forsteri

tags: , , , ,

[Mystery bird] Forster's Tern, Sterna forsteri, photographed at Robbins Park, Smith Point, Texas. [I will identify this bird for you tomorrow]

Image: Joseph Kennedy, 12 June 2008 [larger view].

Nikon D200, Kowa 883 telescope TSN-PZ camera eyepiece 1/350s f/8.0 at 1000.0mm iso400.

Read how to identify this species below ..

Rick Wright, Managing Director of WINGS Birding Tours Worldwide, writes:

A pretty picture, and well composed; with the bird's head turned haughtily towards the observer, we can't see the exact length and shape of the bill or the precise pattern of dark feathers on the head. So let's start with what we can see.

Compare the overall shape of this Forster's Tern with that of a Common Tern. They're both "classic" Sterna terns, but Forster's is noticeably more attenuated -- not just the foreshortened bill, but the tail and legs are longer than those of Common Tern. In this view, note that the tail, just barely visible beneath the folded primaries, nearly reaches their tips; I'm not certain whether I can truly see a white outer vane or not, but if I could, that would distinguish this bird from Common with its dark-margined tail. What strikes me most of all in this image is the length of the tarsus. Just for fun, take this photo and the photo of Common Tern, and ask yourself which bird could straddle the other.

Though the full head is not visible, what we can see of the crown pattern tends to confirm the identification as Forster's Tern. The top of the head is immaculate, and the eye mask is clearly defined.

Review all mystery birds to date.

More like this

Franklin's Gull

Is it just my browser or are the yellow legs part of a different photograph?

In which case, I'll say Arctic tern.

nope, the leg color belongs to this bird. i am not trying to trick you guys, i am trying to help you all learn to better identify birds.

Photograph looks a lot better now; maybe it was my browser.

Now I can see that the legs actually belong to the bird!

And now they're red.

Arctic tern.