Tern ID confirmation, Northumberland Coast, England, 3 November 2022 (1 Viewer)

[Barred Wobbler]

I was surprised to see these 4 terns land in front of me this afternoon, presumably a family group. I'm thinking Arctic, based on general structure, bill length and underlying colour, short legs etc, but the tail streamers are shorter than the wings, but I'm guessing this could be down to wear at this time of year.

 

[Barred Wobbler]

No responses? An Arctic tern was reported from the same place this morning, so maybe I was right with my ID, unless anyone seeing this post knows differently?

 

[Alexander Stöhr]

Hello,
I think the lack of comments is due to multiple birds. No offence you know, but two of your birds look very good for Arctic Tern imo, one is difficult and one is realy hard (at least for me).
The first adult in picture 1 looks good for an Arctic Tern by the features you said and the rounded head with a short, spikey bill (thanks Killian Mullarney!). please note that primaries in very late Arcic Terns became slightly darker due to wear for the same reason as in Common Tern. And I think, darkness is enhanced by excellent image Quality with much contrast.
Second adult bird in picture 2 and 4 is harder for me, but its another Arctic Tern imo.
The 1cy bird in picture 5 and 6 looks very good for an Arctic Tern for mr, too.
the second 1cy bird is the hardest for me, but I agree with you, it might well be an Arctic Tern and a migrating family. But as you know, the two species can migrate together.
Most important: like you, I hope for others to jump in.Thanks!

 

[Barred Wobbler]

Thanks Alexander. They were a surprise to me because all of our local terns left long ago for their wintering grounds. We have 5 species breeding locally at various sites; Common, Arctic, Sandwich, Roseate and Little, but I can't recall when I last saw one. A November record is very unusual.

 

[SteveClifton]

I think lack of responses is in part due to the lack of availability of good ID info on non-breeding sterna terns. Most European field guides don't illustrate them as they usually aren't seen in the northern hemisphere in winter.

I reached pretty much the same conclusion as Alexander, that these are mostly Arctic Terns. In the case of the adult-types, I think AS has covered the main points, but something else which adds support to them being Arctic is that this species (unlike Common Tern) delays moult until arrival on the wintering grounds (per Collins) which perhaps explains why they still have more or less full black caps in November.
In the case of the bird in picture 3, while young Arctic Terns can look similar to this (note the warmer plumage tones & red-brown on the lower mandible) the bills quickly become black shortly after fledging and plumage typically becomes more monochrome. Plumage tones of this bird are still warmer than the other juvenile(s?) but the fact that the bill still has a lot of orange/red tones in early November suggests Common Tern to me. Also, is the upper (central) part of the rump light grey? as opposed to pure white in Arctic Tern. I think the head shape and shape of the dark crown markings also lean towards Common.

Pictures of the spread wings and tails would surely help if there are any...?

Not as late as these birds, but I myself saw two 1cy Common Terns near Hauxley in mid-October, and there are still the odd Sandwich Terns being reported off the NE coast of England this week. We haven't had a spell of really cold weather yet this autumn...

 

[Barred Wobbler]

I think lack of responses is in part due to the lack of availability of good ID info on non-breeding sterna terns. Most European field guides don't illustrate them as they usually aren't seen in the northern hemisphere in winter.

I reached pretty much the same conclusion as Alexander, that these are mostly Arctic Terns. In the case of the adult-types, I think AS has covered the main points, but something else which adds support to them being Arctic is that this species (unlike Common Tern) delays moult until arrival on the wintering grounds (per Collins) which perhaps explains why they still have more or less full black caps in November.
In the case of the bird in picture 3, while young Arctic Terns can look similar to this (note the warmer plumage tones & red-brown on the lower mandible) the bills quickly become black shortly after fledging and plumage typically becomes more monochrome. Plumage tones of this bird are still warmer than the other juvenile(s?) but the fact that the bill still has a lot of orange/red tones in early November suggests Common Tern to me. Also, is the upper (central) part of the rump light grey? as opposed to pure white in Arctic Tern. I think the head shape and shape of the dark crown markings also lean towards Common.

Pictures of the spread wings and tails would surely help if there are any...?

Not as late as these birds, but I myself saw two 1cy Common Terns near Hauxley in mid-October, and there are still the odd Sandwich Terns being reported off the NE coast of England this week. We haven't had a spell of really cold weather yet this autumn...

The bill colour of that bird in the 3rd photo was a bit of a puzzler for me too. No flight shots, I'm afraid. I wasn't quick enough to get the two birds I saw arriving before they landed and when they left, one by one, they flew directly out to sea without any messing about over the rocks, so no flight shots. From them arriving until the last one left it was 45 minutes, with the first leaving after about half an hour.

 

[smiths]

These are all Arctic Terns indeed.

 

[SteveClifton]

These are all Arctic Terns indeed.

I wasn't over confident that it was a Common Tern when I commented above Peter.

Would appreciate if you could elaborate on what clinches the ID...?

 

[smiths]

N°3 (3850) you mean?
The head shape and head pattern look very typical to me, and very convincing for Arctic:
the head is rounded, with a high, domed forehead, giving the bird an overall gentle look.
As for the head pattern, the complete lack of eyering is telling, and so is the smudgy black pattern below the eye, which is more extensive than in Common.
The black cap is solid in front of the eye and widens a lot towards the nape, in a way that reminds me a little of Eastern Rock Nuthatch or a badger...
There is some overlap, but usually the black 'mask' has a more irregular shape in juv./1w Common Tern, with less extensive black both below and above the eye, the latter due to a broader white frontal blaze almost reaching the eye.
Note also the ridiculously short legs of this bird, again pointing to Arctic.
Finally, due to the wing position in this bird, P6 is exposed, revealing another helpful feature not usually visible at rest, which is the extensive white 'tongue' covering almost the whole width of the inner web. In juv. Common, the inner webs of the primaries are largely grey, the clean white colour being more restricted to the inner edge of the feathers.

 

[SteveClifton]

N°3 (3850) you mean?
The head shape and head pattern look very typical to me, and very convincing for Arctic:
the head is rounded, with a high, domed forehead, giving the bird an overall gentle look.
As for the head pattern, the complete lack of eyering is telling, and so is the smudgy black pattern below the eye, which is more extensive than in Common.
The black cap is solid in front of the eye and widens a lot towards the nape, in a way that reminds me a little of Eastern Rock Nuthatch or a badger...
There is some overlap, but usually the black 'mask' has a more irregular shape in juv./1w Common Tern, with less extensive black both below and above the eye, the latter due to a broader white frontal blaze almost reaching the eye.
Note also the ridiculously short legs of this bird, again pointing to Arctic.
Finally, due to the wing position in this bird, P6 is exposed, revealing another helpful feature not usually visible at rest, which is the extensive white 'tongue' covering almost the whole width of the inner web. In juv. Common, the inner webs of the primaries are largely grey, the clean white colour being more restricted to the inner edge of the feathers.

Yes no.3 was the bird I was referring to. Appreciate the detailed analysis of the bird👍