Which Tern? Iran, Golestan, May 2022 (1 Viewer)

[Pedrambirder]

Hi all,
Little or Saunders's Tern?
I think the right one looks different, at least in two keys, the black on forehead is covering the eyes and the bill looks slimmer!

 

[Muppit17]

The species pair are very difficult to tell apart. However Saunder's is a maritime tern and one rarely seen in this area away from the Gulf coast.

If I understand correctly the location is in North Iran close/on the Caspian Sea eastern shore. I know of no ST records from there.

Certainly one bird looks definitely Little but although the other facial markings look possible, both species are known to be variable. In addition, I certainly would not like to claim a ST without noting the rump colour & the number of dark primaries.

There is a good summary here Little Tern vs Saunders's Tern | uaebirding

 

[andyb39]

Both Little Terns. Neither bird has the prominent white edge to the folded primaries typical of Saunders's, and both birds have orange-yellow legs and roughly the same upperparts coloration. The right-hand bird in the 2nd image has a slightly Saunders's-like head pattern but other things don't add up. As @Muppit17 says, the location isn't right for this species anyway.

 

[Pedrambirder]

The species pair are very difficult to tell apart. However Saunder's is a maritime tern and one rarely seen in this area away from the Gulf coast.

If I understand correctly the location is in North Iran close/on the Caspian Sea eastern shore. I know of no ST records from there.

Certainly one bird looks definitely Little but although the other facial markings look possible, both species are known to be variable. In addition, I certainly would not like to claim a ST without noting the rump colour & the number of dark primaries.

There is a good summary here Little Tern vs Saunders's Tern | uaebirding

Thank you,
Yeah, as the climate condition has been changing alot since last decades, we've observed some uncommon species in central of the country, which have belonged to south coast line near Persian Gulf before, so for some suspicious species, I usually try to find the ID keys first, then I would check species distribution range map, beside.
Thanks for the useful link, also.

 

[Pedrambirder]

Both Little Terns. Neither bird has the prominent white edge to the folded primaries typical of Saunders's, and both birds have orange-yellow legs and roughly the same upperparts coloration. The right-hand bird in the 2nd image has a slightly Saunders's-like head pattern but other things don't add up. As @Muppit17 says, the location isn't right for this species anyway.

Thank you for the ID keys.