Saturday, 25 September 2021

How Not to Find Good Birds

A busy week of work has played havoc with important stuff, and the last time I managed an early-morning beach inspection was Tuesday...

Three Whinchats bottom left, and the chalk cliffs of Beer Head in the distance, further round the bay. Exactly 17.04 miles (27.43 km) as the Whinchat flies.

These next two from Sunday morning...

Even when the birding is a bit quiet, it doesn't matter.

Reed Warbler. Still a few birds to be coaxed out, but no Sedgies for a while now.

The main highlight from the last couple of outings was a game of hide-and-seek with at least two Grasshopper Warblers in dense sedge at West Bex. Not the best views, but better than the zero encounters with the species I'd managed so far this year.

Which brings us to this afternoon...

A gentle stroll from West to East Bex and back was punctuated by the very occasional 'hweet' from the bushes and little else. By the time I began the return leg my Chiff tally was a very modest six, and a single Whinchat had felt like a major prize. Thankfully there were a few gulls to look at. The East Bexington fields have all been harvested, and several turned over a bit (harrowed?) which definitely pulls in a few birds. It was nice to see double figures of Med Gulls decorating the countryside again.

Mostly my walk had been very lazy, with barely any effort to deviate from the path and have a poke around, but at West Bex I thought I should at least head down to the waterline and check the beach properly. I was pleasantly surprised to discover a decent bunch of big gulls hiding behind the lowest shingle ridge. In the distance was an interestingly white-headed bird with obviously white-tipped, black tertials. As far as I could tell it was definitely a bird in its first calendar year. Through binoculars it appeared to have quite boldly marked second-generation scapulars, so I decided it looked a good candidate for a Yellow-legged Gull in well-advanced 1st-winter plumage. Immediately I got the camera out and began to take photos, gradually creeping closer. I did consider the possibility of Caspian Gull, but the scapulars put me off, plus the head/bill combo didn't have a very Caspish vibe. Mind you, there was clearly something amiss in that area because the bird seemed unable to close its bill properly.

As I slowly approached, the nearest gulls began to lift off and head west along the beach. Eventually the target bird took off also but, unlike the others, flew east and away. Turning around I spotted Mike Morse behind me. Mike had timed his arrival well and, though he missed seeing the bird on the beach, had managed some flight shots. We chatted briefly, and when he had gone I had a look at the burst of photos I had taken when the gull took flight. Hmmm...

The first thing I noticed was a prominent, 'venetian-blind' type inner-primary window, quickly followed by a gleaming white underwing. Neither is a good feature of Yellow-legged Gull. But both are good features of Caspian Gull! Oops. There wasn't much more I could do until I got home and uploaded the pics to the laptop. Here is a generous selection...

Initial views. Looking at these photos now, I'm not sure why Caspian Gull alarm bells didn't ring more loudly...

The tertials are much more Casp than YLG, with those broad white tips rather than thumbnails.

With that ever-open bill it is difficult to get a true idea of the bird's 'look', but I think it's obvious that the bill is not a heavy one.

Those scapulars are quite heavily marked, but within the Casp spectrum. Considering it is still only September there is an amazing amount of moult in the wing coverts! The inner greater and median coverts are all new. Some of the first-generation greater coverts are a bit chequered, but again within variation for Casp.

That white underwing is absolutely spot on!

The inner-primary 'window' is more prominent than you would expect on Yellow-legged Gull.

Tail pattern looks great. Very black terminal band contrasting strongly with white tail. Just a few blackish flecks elsewhere.

Most of the greater coverts look nice and plain.

So. Plumage-wise I'm pretty happy to call this a Caspian Gull. But...

I did run some photos past a gull enthusiast who encounters far more Caspian Gulls than we do in this part of the country. He thought it had the feel of a German type Casp, and that the head shape possibly let it down. Looking at all my photos now, the bird does appear to have a swollen lower jaw, and the right side of its face appears lumpy too. So it is difficult to accurately assess its 'look'. Possibly the safest plan is to let it go as a possible hybrid. If I'm being honest I am a bit loath to do this because Caspian Gull is still a very nice find in Dorset. However, the way I 'found' it was hardly a stellar performance in bird identification, so...

Anyway, I'll close with Mike's excellent flight shots...

© Mike Morse

Look at that underwing! Persil white!! © Mike Morse

© Mike Morse

© Mike Morse

After the thrilling gull stuff it was all a bit of an anticlimax, until my one and only Wheatear of the afternoon injected some welcome pizzazz...

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