Monday, 4 December 2017

Larking About at Staines

Last week an American Horned Lark was reported at Staines reservoir, having apparently been present just over the road at the (permit only) King George VI Reservoir for some three weeks prior.  Now the Horned/Shore Lark complex is a tricky one as far as species are concerned. Eremophila alpestris is know as  Shore Lark  in this country though called Horned Lark elsewhere in the world and is presently classified as having forty or more sub-species throughout the world. However, the word on the street is that the whole Horned Lark complex may well be split (perhaps in up to six separate species), of which our own Shore Lark (E.a. flava), that winters along our eastern coastline, would be one - see this Birding Frontiers article from a few years back. Now, whilst it was generally agreed that the bird at Staines was definitely an American Horned Lark there was much debate on Bird Forum about which sub-species it was, though the consensus was one of E.a. alpestris, hoyti or praticola. So whilst at present this bird would just be an interesting sub-species tick, there was a possibility that it might become a full species in its own right at some point down the line so at the very least there was an insurance visit required. What's more I am still in two minds about whether to follow strict BOU listing standards or to adopt my own broader standard so it's possible that in the future the Gnome Rarities Committee might accept American Horned Lark as a tick in its own right. Anyway, the bottom line was that I was bored and it wasn't very far away so I went to see it.

I've been to Staines Reservoir a number of time previously. It's a rather bleak place and the birds are often rather far away. Indeed whilst the Lark in question had been showing nice and closely along the causeway bank on the Saturday, by the time I visited on Monday it was firmly ensconced along the western bank of the northern reservoir though fortunately when I visited it wasn't too far away (about 100 yards) so I was able to get reasonable views. In order to see it you either have to stand further away where the fence is low enough to see over or closer but then have to peer through some rather imposing metal fencing. I tried both spots and in the end the peering through the fence wasn't too bad.

The bird was on show constantly in the same spot for the hour or so that I was there. The most striking thing about this bird was the white extended supercilium instead of the yellow of our birds. It also looked plainer and darker though apparently that can be more objective. There's a lot of  discussion about subtle plumage differences on the Bird Forum thread for those who are interested but the white supercilium was by far the most obvious to me.

 Some digiscoped video footage of the Lark

Apart from that there were some distant Pochard, Wigeon and Teal as well as a couple of Egyptian Geese. There were no Black-necked Grebes about for which this reservoir is well known during the winter months, just a few Tufted Ducks bobbing about in the waves. The southern reservoir seemed to have been drained and was showing large areas of exposed mud, looking strikingly bleak.

The partially drained southern reservoir
A proper photo of the Staines American Horned Lark taken on Saturday when it was on the causeway shore,
courtesy of Ewan Urquhart, showing it's striking white supercilium and generally darker appearance

After an hour or so I felt that I'd seen all that I was going to see so wandered back along the causeway and headed for home. So, all in all a nice bird to see at a reasonably close distance to Oxford and the possibility of an armchair tick down the line. All in all, not a bad way to pass a Monday morning.