Plimmerton tern ID

[Michael Szabo]

Peter Langlands has posted these photographs of a putative Arctic Tern that he found yesterday on rocks at Plimmerton with a flock of c.150 White-fronted Terns. What do others think?

[AlfieB77]

Great find, do you think it will still be there by the weekend?

[Michael Szabo]

The one that I found at Waikanae sandspit with Eddie Bright and Elizabeth Taylor in April was seen again at the same spot 2 days later, so it is possible. If anyone sees an Arctic Tern at Plimmerton in the next 2 days hopefully they will report it promptly so others can try for it.

[tim]

From the photos its looks like a little 1st year white fronted tern.

[Oscar Thomas]

I would say structurally it looks good for Arctic tern - smaller than WFT with small rounded head and shorter bill and legs. The primary pattern should be enough to exclude WFT (no white along the top edge of the feathers, dusky grey overall) which is clear when comparing to the wingtip to the left of the first photo. The head markings are variable but still fit for an immature/NB Arctic tern. Seeing the underwings would help clinch it though.

[tim]

Bill size is exactly the same when comparing the bird in background, considering that the tern in front is closer.
The dark primarys fit well for a 1st year white fronted tern.

[Steve Wood]

The diagnostic “short legs” don’t seem to apply on this individual.

[AlfieB77]

Whereabouts in plimmerton was it found?

[Oscar Thomas]

Having taken a 12th look at it I think Tim and Steve are right and it probably is just a runty WFT with worn wingtips. Makes it challenging when it seems to show a mix of features from different species.

[sav]

I would say structurally it looks good for Arctic tern - smaller than WFT with small rounded head and shorter bill and legs. The primary pattern should be enough to exclude WFT (no white along the top edge of the feathers, dusky grey overall) which is clear when comparing to the wingtip to the left of the first photo. The head markings are variable but still fit for an immature/NB Arctic tern. Seeing the underwings would help clinch it though.

Hi

I'm afraid that I don't agree with Oscar's statement. The structure of this bird, to me, just doesn't look like Arctic at all. Arctic Tern has a front-heavy jizz that this bird doesn't display, and the head shape is wrong. Its legs are way too long, as is the bill.

I've just seen 2 WFTs in Hawkes Bay today that look more or less identical to Peter's bird.

cheers