Juvenile Thayer’s Gull in Aberdeen. NOW!

BOOM!

Thayer’s Gull, Donmouth, Aberdeenshire. 20th Jan 2016.

It’s an open secret. Chris Gibbins and I are working on a GULLS BOOK.

So the obvious thing- go out and find an uber rare gull of course. DOH!

Chris Gibbins writes:

“Isn’t birding just brilliant.

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Exciting. Challenging. Sometimes stressful. Often mind-blowing. And sometimes simply bonkers.

Thayer’s Gull, Donmouth, Aberdeenshire. All photos: Chris Gibbins & Hywel Maggs.

I had made a conscious effort to escape from work more over lunch. Rather than work and have lunch at my computer, I’d promised myself that for 2016 I would go to Donmouth to check the gulls over lunch. A kind-of New Year resolution. I’d been doing this since going back to work after the Christmas break, but in the last few days I was particularly spurred on by Dave Foster. Dave had been finding lots of Caspian Gulls back home in NE England over the last 10 days or so, and Dave’s text messages and gripping Caspian photos reminded me to plug away with Donmouth.

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Tuesday 19 January. I arrived at Donmouth. The tide was just beginning to drop and birds were gathering on the gravel bar. As I wandered along to my usual viewing point, I noticed a gull just below me, very close to the base of the cliffs and just 30 m or so from me. It looked odd. I put my bins up and looked at it – ‘ooooohhh…. here we go’. I put my scope up and started to have a close look.

I look at gulls a lot. One consequence of this is that I see lots of wacky birds (e.g. crazy-looking Herring Gulls), birds that fall rather clearly into the presumed hybrid bracket, and others that don’t quite fit anything. Thus, when confronted with something initially puzzling, my default position is always ‘why isn’t this simply a weird Herring Gull, or a hybrid etc’. But as the features of this Donmouth bird were registering themselves in my mind, this slightly negative default did not kick in – it looked just like a proper gull, and that gull was Thayer’s. That said, I had to be careful not to let first impressions run away with me (‘‘stop, concentrate on the details; be objective’’ I told myself) but boy was this an interesting bird.

The bummer was that, having just nipped out over lunch, I did not have any camera kit. This was critical as a bird like this really needs to be captured in flight. I spent 5 or 10 mins looking at it and running through the options; it was no Herring x Glaucous hybrid, nor did the features add up to a small Glaucous-winged. Over the Christmas period I’d been in Korea looking at gulls, and had seen many puzzling birds that I took to represent various hybrid combinations involving Glaucous, Glaucous-winged, Slaty-backed and Vega. But this bird was not like any of these. For sure it had that Pacific look (largely dark tail and well-marked rump and upper-tail coverts) but it was not like anything I’d seen in Korea. It was either a Thayer’s or a crazy dark Kumlien’s. This is the real nightmare zone, but several things had me leaning towards Thayer’s to me – those amazing fresh, scaley scapulars (like a juv Baird’s Sand), the tertial pattern was good, and the primaries had a narrow fringe confined to the tip (not bleeding along all the feather edge). The primary tone changed a lot in relation to angle and the light conditions (cloudy but sun sometimes breaking through and creating glare) but overall I judged them to be more or less the same as the tertials, but perhaps slightly colder/greyer in tone. Some Thayer’s in my photo collection show primaries the same as tertials, others slightly darker. So this bird seemed okay in this department. Any paler and I would get the jitters. Stills don’t do it justice to its jizz, but walking around and interacting with Herring’s it was obvious it had its own character. It was just fractionally smaller than a Herring with a pinched-in bill base. Slightly snouty. It was rather aggressive and long calling too – how many time have you seen this on an Iceland/Kumliens type? All this was good but I needed flight images. I’d managed some video footage and stills of it on the deck using my phone. Fine, but I really needed to see the details of the open wings and tail/rump frozen in a flight photo, rather than relying on perceptions of them in the field. Dam. No camera. I needed help – some second opinions from friends who were not quite so adrenalin-fuelled or stressed as me, and so could look objectively, and pictures were needed

Thankfully Hywel Maggs lives not far away and he was there with his camera within 15 mins. I left Hywel to try and secure some pics and bombed off to pick up Paul Baxter to get his views on it – he was stuck at work with no car. By the time Paul and myself got back, Hywel had it all under control. Myself, Paul, Hywel and Phil Crockett (who I had also rang for a second opinion and managed a brief look between work duties) discussed the bird; to cut a long story short, were in agreement. It was great for me see and hear their instinctive reactions to seeing it.

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I had to get back to work but this provided me with the chance to put the news out on the email systems etc. Most importantly I emailed a couple of my phone pics to folks whose views I trust more than my own – Peter Adriaens and Martin Garner.

Accepting that they had just my phone-scoped standing shots to go on, both quickly came back with positive, ‘thumbs-up’ type comments. We have lift-off. I waited to receive some copies from Hywel of his flight pics, but at least for the time being there were no big warning lights. The news was out and no doubt the usual Thayer’s-Kumliens’ debate (ID, taxonomy…) would ensue over the internet. These birds are always going to be the subject of discussion and everyone will have their views. All part of birding, and how it should be.

(all pics Mr. Gibbins and Mr Maggs, Donmouth, Aberdeen, NE Scotland – YESTERDAY)

COMMENT from Martin G.

No doubt as already intimated by Chris G. there will be internet/ social media debate. What did I think/ It looks like like a Thayer’s Gull. (This really not necessary- already cracked by Chris!!)

“20 years  after my first Thayer’s. A crazy amout of juvenile only upperparts (lack 2cy feathers). Same fillled in JUVENILE scapulars. Same pinched base bill. Same velvety underparts, same  tertial pattern, morphing colour to primaries (but LOTS look just like this, spot on secondaries and tail). There- it’s what CHRIS SAID!

THAYER’S GULL…    see ya later”

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Below- 2 fresh juvenile Thayer’s Gulls on breeding grounds…

Postscript from Chris Gibbins:
‘‘I’ve just come from Donmouth where the gull is still present. I saw it briefly but light conditions now very neutral so ideal for judging its overall colour tones.

I have to say that I have concerns having seen it in these conditions – it looks rather too milky to my liking. John Nadine’s fantastic image from the other day of it standing on the groyne make it look good, but today I have come away with rather different perception of it. In neutral light the primaries do not look dark enough and the secondaries and outer primaries in flight not quite contrasting enough for me – or at least to put it beyond doubt. I thought I should voice my new concerns about it.

Whatever, it is a great bird. Best thing is to see it and make your own mind up. ‘’

Chris

Dr Chris Gibbins
Senior Lecturer
Northern Rivers Institute
School of Geoscience
University of Aberdeen
Old Aberdeen
AB24 3UF
Telephone: 01224 272338
e-mail: c.gibbins@abdn.ac.uk
Web page: www.abdn.ac.uk/nri

Humble Pie from MG- yes it is right at the pallid end. Yes I probably jumped the gun- though I still some can look like this (see photo below). Some cases will never know for sure.

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One thought on “Juvenile Thayer’s Gull in Aberdeen. NOW!

  1. Gregory Shepherd (@ShepherdGregory)

    Glad you liked Donmouth:always intrestin times at the Estuary:
    fishin for flatties,and the evening sun appears,image never forgotten,
    and made up for not catching anything!(Did hook a finnoc that day,
    but failed to strike~never was that great a fisher! Greg

    Mention that neck-the-woods/Brig O’ Balgownie in a poem[‘Kicks’],
    deservedly so.

    Reply

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