Old Caley's Diary: Lesser or greater? It just doesn't add up!

On Friday 17th November a greater scaup was discovered at Farmoor. Another greater scaup, in eclipse plumage, had been found there at the end of September but I had contrived to miss that bird by inches. So on Saturday morning Mrs Caley and I duly returned to the reservoir to pin down the duck. However despite an enjoyable walk around most of Farmoor, we failed to locate the scaup and left empty handed once again. Imagine my chagrin then when the duck was re-found later on Saturday afternoon! Interestingly though after local birders had viewed the photos posted online the consensus shifted to the opinion that this greater scaup was in fact a lesser scaup, a much rarer species from North America and a bird that I'd only encountered once before when I saw two males at Drift reservoir in Cornwall over ten years ago.

So on Sunday I waited until receiving the news that the duck had been seen that morning and then hot tailed it back up to Farmoor to see for myself. As is frequently the case the duck was showing well but right over the other side of the reservoir from the car park so we'd have to walk for a good mile to see it! Of course if I had been clued up I could have parked right next to the southern bank but hey, I wasn't! After a 20 minute slow trot, Mrs Caley and I joined the throng of half a dozen or so birders and settled in to enjoy the rare vagrant bird. The lesser scaup showed brilliantly well, often coming within 20 metres or so of the shore and allowing frame after frame filling shots. It appeared to have all the features of lesser scaup, lacking the crest of the tufted ducks that it associated with, having a grey vermiculated back and a small black nail to the bill. A small doubt that I had though was that it seemed larger than the tufted ducks and I had read that lesser scaup was supposed to be slightly smaller. Still the general opinion from the gathered watchers was that it was a lesser scaup and that views of the open wings underlined this, lesser scaups lacking the outer whitish primaries that greater scaup possess. I failed to capture the open wing pattern on the camera though so was unable to check this.

Some comparison shots with tufted ducks and coot.

And a few diving and preening shots.

We went back home very happy that we had added lesser scaup to our (non-existent) Oxfordshire lists (really must write that up one day). Then midway through the afternoon a post on Oxonbirdingblog suggested that the bird might actually be a hybrid. Horror! And indeed, after being seen on Monday by far more qualified judges than I, the bird was demoted to hybrid status, possibly tufted duck x greater scaup or lesser scaup x greater scaup.

The analysis is excellently detailed on www. oxonbirding.blogspot.co.uk so please read there if interested in a more scientific description.

Still it was a fabulous duck and I managed to get some nice photos if nothing else!

Some of the other birds seen over the weekend while looking for and at the duck.

blue tit (pinkhill)