If not a White-cheeked Tern, then what?

It is raining outside, Covid lockdown still has its grip upon us, so, as a refuge, let us travel back in time and revisit a bird that caused many eyebrows to be raised and a rarities committee to pronounce it as 'not proven'. I give you one White-cheeked Tern, at Dungeness, Kent on 13th May 1989. These are my notes that were submitted to the BBRC at the time.

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At approximately 10.00hrs, P Boxall, JP Siddle and RE Turley and myself were sitting in the common room at Dungeness Bird Observatory when two birdwatchers came into the room and, whilst chatting to us, casually mentioned that they had been watching a tern feeding over the 'patch'. They described it as being "a Black Tern with with white cheeks which was as large as a Common Tern".

All four of us left our hot drinks and drove to the area of beach opposite the 'patch' - an area of sea disturbed by the power station outflow some 100m offshore. When we scanned the patch, the bird that had been described was still on view. The bird confounded us as to an immediate identity. As we continued to watch the bird from the beach, D Walker came out of the seawtaching hide overlooking the patch, where, together with A Hughes, he had been watching the tern. They had first seen the tern from 300m further east and had come closer to investigate further. We all then went into the hide together, and all six of us started to slowly, and carefully, observe the bird. We discussed all aspects of the bird, gathering a thorough description. We still did not have a firm identification, although we knew it was a 'Sterna' tern which could quite possibly be a White-cheeked - but wasn't that just wishful thinking?

A Hughes then returned to the observatory and fetched a copy of Harrison's 'Seabirds'. This was not helpful in us being able to confidently identify the tern, and led to some confusion. D Walker and RE Turley then returned to the observatory to get further reference. Before they returned, the tern left the patch and flew eastwards and out of view. It was not to be seen again at Dungeness. At this point I had been watching the bird for 30 minutes. On D Walkers and RE Turleys return, with the aid in particular of 'Birds of the Middle East and North Africa' by Hollom, Porter, Christensen and Willis; plus BWP Volume 4, we were able to identify the tern, with confidence, as a White-cheeked.

The first impressions of the tern was that it was the same size and shape as the 100+ Common terns also present. This tern was obviously darker than them of both upper and underparts, with the most striking feature being a white cheek patch on both sides of the face.

Medium-sized tern, being the same size and shape as the accompanying Common Terns except that the bill looked slightly longer and more drooping. The tail, although noticeably forked, lacked long outer tail streamers.

Forehead, crown and nape black, forming a dark crown, which extended down to above the lores and apparently below the level of the eye. This suffused out onto hind-neck, neck sides and lower ear-coverts.

Mantle, rump and tail a uniform dusky silver-grey, much darker than Common Tern but not as dark as to be expected of a Black Tern, although approaching the latter species.

Wings dusky silver-grey as upper body, except for very obvious silver primaries, more obvious on the inner-primaries, which 'flashed' in the light at certain angles. The outermost primaries, and their tips, were dusky silver-grey. The trailing edge of the secondaries were distinctly edged off-white. Underwing smoky grey, with a whitish band appearing along the underwing greater coverts, rather reminiscent of Sooty Shearwater.

Underparts a darker grey than upper parts, rather uniform in colouration, extending from lower throat, breast, belly, flanks to the under-tail coverts. This colouration met up with the black neck-sides and lower ear coverts.

This left the white 'cheek' patches, which were rectangular in shape and slightly rounded at the edges towards the back of the ear coverts/ hind neck. These white patches extended from the region of the lores and bill base and onto the upper ear coverts. The shape of this white area was striking and stood out well against its dark surround.

Bill dark.

When flying with Common Terns over the patch it appeared no different in jizz from them (but see note on bill shape) and fed in the same manner, by dropping down to just above the disturbed sea and picking at prey items on the surface. When flying eastwards, flight as Common Tern.

We were sure in ruling out the tern being an oiled or melanistic bird because (i) all non-dark areas of the bird, such as the cheeks, trailing whitish edge to the secondaries and pale bar on underwing coverts were symmetrical and of the same shape; (ii) all of the dark colouration was not blotchy or erratic.

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We took all of these notes, as a group, before we had access to any literature, so that at the time we had no knowledge as to what field characteristics to look for. When we were able to read up about White-cheeked Terns we were astonished to find that we had clearly noted some important features. As was typical of most birders in 1989, none of us had a camera, so no image was ever taken of the bird.

Several descriptions were sent to the BBRC, together with a painting created by RE Turley (that was also published in ‘Birding World’). This would have been a British first had it been accepted, but the BBRC rejected it. I had been told that the submission made by the original finder (by his own admission an inexperienced birder) was contradictory to those submitted by the rest of us. Rumour had it that it received  a rocky ride from a Middle-east based birder who was called upon for his expertise. Whether either of these facts are true, I do not know.

So, 32 years after the event, what do I think about it all? I rarely think back to the bird, but when I do I feel that it was what we claimed - an adult White-cheeked Tern. Checking the plethora of literature at our disposal now, and a more robust knowledge of the species, we did nail a number of identification features.

Pro: In Olsen and Larsson’s ‘Terns’ (Helm) they state that ‘underwing diagnostic: dark secondaries show good contrast with whitish median and greater coverts’ - we got that.

Pro: Mantle, rump and tail concolorous, lacking the contrast shown in Common and Arctic Tern.

Pro: Flashing silver primaries, mentioned in many references as notable. I was told back at the time of our sighting that sterna terns flying out to sea in the Middle East were often picked out as being White-cheeked because of this feature.

Cons: White-cheeked (length 32-34cm, wingspan 78-83cm) is considered to be smaller than Common Tern (length 31-35cm, wingspan 77-98cm). Bill colour stated as red with black tip, and we called it as an all dark bill. EDIT: I have been sent an image of an adult White-cheeked Tern that shows an almost wholly dark bill, and, on seeing Ray’s painting once again, he has painted the bill with a black outer half that merges into a dusky red along the rest of its length. Also of interest, in Nils Van Duivendijk’s ‘Advanced Bird ID Guide’ he states that W-c Tern exhibits a long, evenly slender bill USUALLY WITH A SLIGHTLY DROOPED TIP!

I reckon that if our bird had been a second, or third for Britain at the time, it would have sailed through. And shall I let you in on a secret? Regardless of what the BBRC, and 99% of birders might think, it’s on my list...