Tuesday 25 February 2014

Pale-bellied Brents and Odd Gull

I had a very enjoyable hour or so birding after work this afternoon. With the evenings drawing out the birding potential is definitely on the up! Off the Imperial this evening were three dapper pale-bellied brent geese - the first I've seen for ages. I'm assuming they are wintering birds that are normally elsewhere on the estuary as they normally move in the spring after the bulk of the dark-bellied brents have gone. There have been really high April counts on the Exe and they are now expected in numbers in the spring. Also this evening c80+, common gull, just 10+ lesser black-backed gulls and a smart adult summer mediterranean gull. A lone guillemot was drifting down river looking none too healthy and I counted 1 great crested grebe, 2 goldeneye and 35+ red-breasted mergansers.

The view from the coach park looking across to Cockwood with the Imperial rugby ground on the left.

I photographed this herring gull off Mudbank yesterday afternoon. There is nothing really at odds, plumage-wise, with it being a first winter herring but I feel a little uneasy about it. Firstly it has, in my opinion, a mild 'cachinnans' feel to it and I wonder if there might be some caspian genes lurking somewhere? The most odd feature is the paler 'band' across the greater coverts contrasting with darker bases. It's certainly not the classic 'cachinnans' pattern, or even close to it, but it's odd for herring gull too and I've seen photos of caspians showing patterning close'ish to this. Whether or not they are pure caspians of course remains open to question and even if this bird looked very like 'cachinnans' in other respects I think its wing coverts would rule out its acceptance as being pure. The tertials are worn and of little help and there are no pale tips to the median coverts that, on caspian, combine with the pale greater covert tips to give a double 'wing bar' effect. The bill is not great - quite short and a bit bulbous-ended and the head isn't gleaning white but it still feels a bit odd to me.

A bit of a bulge behind the legs in this shot but it doesn't look long-winged.

Note the smooth contour to the neck and the light neck streaking. The legs are not long and certainly not spindly and they are as pink as the herring gull to the rear.

I'm annoyed this is the only under wing shot I got and I missed seeing it properly in flight. You can't see anywhere near enough detail but it's not especially dark and neither does it look particularly pale. The overall feel is much more herring-like in this pose and the tail/upper tail coverts looks like bog-standard herring. I'd be really interested to see what anyone else thinks. Am I going mad or does it look a little unusual?

1 comment:

  1. Hi Matt, agree, certainly worth a closer look and it would have caught my attention but I'm sure you're right with HG masquerading as Caspian. I see what you mean about the GC but the rest of the wing looks fine for a pale HG - can't see any moulted coverts either. As you say, structure fits HG best in every way as do the tail and underwing.

    Anyway, after your Kumlien's and Glaucous Gulls surely it's somebody else's turn with the next Caspian? All the best.