I think the early Id when it first arrived and the early pictures muddied the water with this bird ,once seen and photographed there was little daupt that it had the full set of features of White-winged Black Tern ,and the paler brown patch was not like the dark patch of a black tern. It was a Cracking county bird and im glad I spent an evening with it ,even its general flight and behaviour was White-Winged Black Tern. What Ian and JR said below perfectly sums it up. Nice for it to be slightly different ,it made for an interesting viewing. :)
Well, let's start with the conclusion, 100% a White-winged Black Tern for me.
I too noticed vague greyish pegs in the field but nothing like as pronounced as in some photos. Add to that the obvious field marks of brown-toned mantle contrasting a white rump and reduced black around the head with typical 'earphones' and for me the ID was secure. But I was interested in Jon's comments on the bird's call. I also heard it calling when it was being harassed by a Black-headed Gull, typical tern-like but rather high pitched and squeaky. Since the posts on here I have checked Xeno Canto and can find recordings for either species that fit my memory of the call. As it was being chased at the time it might have been an alarm call but that only exists on XC for Black Tern. I would discount any hybrid theory. Surely a hybrid is more of a rarity that a pure White-winged Black Tern but, if going down that path, why not muddy the waters further and suggest a 'mixed singer' as in Chiffchaff/Willow Warbler hybrids. No, In my opinion, not a hybrid but a pure White-winged Black Tern
No problem with this being a White-winged Black Tern in my opinion and in fact the breast 'peg' always looked 'worse' in photos than it did in the field for me over the couple of visits I made (and speaking to those birders I knew at the site too) and I think the feature on this bird has been slightly misinterpreted from images somewhat. The 2008 Heaton Park Reservoir juvenile White-winged Black Tern also showed a similar looking 'peg' to the High Rid bird (I wrote an identification article on the back of it which is unfortunately not accessible on the website currently) and out of the hundreds of juveniles I've seen abroad its not as rare as you might think. Indeed, having now seen seen eight juvenile White-winged Black Terns in the UK, two of them have shown these 'vague pegs', so that's 25%!
But a couple of questions for those who studied the bird closely in the field.
Does this 'vague peg' really look like that possessed by a juvenile Black Tern, in distribution/extent or indeed in colouration?
Is there anything else about this individual (structurally or plumage wise) which did not fit that expected of a juvenile White-winged Black Tern, bearing in mind the more subtle identification features too?
Both a distinct no for me, though I will add again that this is merely my own personal opinion.
A quick google search for images of White-winged Black tern Juveniles resulted in several images where the birds showed similar 'pegs'. Perhaps the best is from the Oxon Birding blog. In most of the instances I looked at, the pegs were very similar to the images on the High Rid thread, in that they appear more brownish than what I have seen on Black Tern. Possibly.
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Really kicking the tyres on this ID aren't we? Maybe I sounded smug before? Not intentional if so. I heard it calling on Wednesday and found a WWBT match on Xeno Canto, but it proves very little as Jon says.
I posted this to my friends on social media yesterday, it may be of some interest:
"Circumstances found me at High Rid res. this afternoon. I'd had a look at the distant tern (no scope) and was just chilling out, sat on the bank of the res. when I heard a call - the tern was being chased by a BH gull. It got me wondering how a WW tern call differed from a B tern call. I have the Jean-Claude Roche discs on my phone so I had a listen to both calls. What I'd just heard sounded more like a Black tern to me. So next time the tern sailed by I played the WW tern call - no response. I did it two or three times more - no response. So I tried the Black tern call - the bird immediately flew towards me, over my head and out of sight beyond the trees, away from the res. A few minutes later it returned and resumed quartering low over the water. Five mins later it came close once more so I tried the Black tern call again and once more it responded, flying straight towards me, this time calling. Again it disappeared behind the trees, taking longer to return, and when it did it stayed much higher, fly-catching 100ft+ above the res. - it was still doing this 15mins later when I left".
And, after some discussion:
"I can't explain the tern's reaction to the call. Maybe it didn't hear the WW tern calls, though I can't see why it wouldn't; perhaps (as Colin suggests) it reacted to the Black tern call anyway - their ranges overlap and it's a juvenile; maybe they share some calls, or react to each other's call for some reason (food, migration?). The call I heard from the tern sounded more like a Black tern than a WW, but that's only going off the two calls off Roche's discs (there are dozens of calls on Xeno-Canto!). I'm not suggesting the ID is incorrect, just thought it was interesting behaviour".
Anyway, that's it. People can draw their own conclusions as to whether any of the above is of any relevance.
I have the Helm ID guide by Keith Vinicombe, and he is cited in the Alstrom article as reporting one of these hybrids. Vinicombe in his book describes a bird with the WWBT wings, rump and saddle, but Black Tern 'pegs' and structure. What a minefield these things can become, as in that case it sounds like the plumage characters of this High Rid bird would not rule out the hybrid ID.
That's possibly enough rumination though? I'm not coughing up this one now, it's a lifer in GM!
Thanks for referring me to the Alstrom article which I have just read and found very comprehensive.
I agree totally that the bird is White -winged Black Tern, it's just that I was puzzled by the present of the "peg" and you have now clarified that aspect for me, so I am grateful to have learned something more.
As a separate matter of passing interest, the Alstrom article cites recorded hybridisations between White- winged and Black Terns in the former USSR, Canada, Sweden and Netherlands, with several likely hybrid birds noted in UK in the past. However this is not to cast any doubts on the High Rid individual which looks 100 % solid; - no hybrid could show such a classic clean white contrasting rump, - it would surely look noticeably greyer?
Cheers,
Mike
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I went to see this bird yesterday and Dennis Atherton pointed out the 'pegs' to me and said it was a niggle. 'Bah, there goes my lifer' I thought. We watched the bird and noticed that the pegs were not symmetrical, the left side one was bigger and from back of camera views they were both brown.
I found this article online with a helpful note on page 13:
"The underparts of White-winged Black are white and unmarked. Exceptionally, there is a brownish patch on the sides of the breast, but it is never so large, clear-cut and dark as on Black Tern."
Thank you Per Alstrom, I will buy you a brew and some chips from the van next time we catch up at Penny Flash!
Being more serious, alongside the saddle, rump and wings, I did note the bill and head shape looked good, when you look at the drawings in the article on pages 3 and 4 and then the various photos about. The black crown does not extend that far forward either. The article is pretty old, published in 1989. But at least it is out there.
I have ticked it as a WWBT, because I think the collection of 'pro' features is overwhelming and there is an explanation in this article for the 'anti' feature. It was great that Dennis mentioned the issue though as I would not have realised otherwise and I wouldn't have looked as hard at the bird. It was superb to watch, highlight was a tussle with a Black-headed Gull right in front of us, which the Tern won, seeing the gull off completely!
I haven't been down to see the High Rid White-winged Black Tern but have been very interested in studying the rather educational photos posted by observers on site; culminating in Colin Davis's excellent flight shot of the culprit ( flying left ) today.
This bird obviously doesn't know it should not be sporting a "shoulder peg", which looks very conspicuous on this latest image.
I had noted hints of this on some of the previous available photos where it appears as a short thin finger, though it takes a bit of imagination to see any sign of this on other images. It's just as well it has a blazing white rump contrasting with its saddle, otherwise this could have been quite a puzzling bird, though observers on site and with prolonged views no doubt were able to note its other finer points and flight jizz.
I have no experience at all previously of the species showing such a shoulder peg nor do I see any mention of this possibility in my literature at home;- any thoughts anyone?
Regards,
Mike P
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