Articles - Greater Yellowlegs: Camel Estuary, Cornwall, 12-13 September 2011

On 12 September, at approximately 10.40 am, Roger Pickford was sitting in the newly opened bird hide at Treraven Meadow, just south of Wadebridge, Cornwall, when he noticed a yellow-legged wader arrive and start to feed at the edge of a small flooded pool, just north-east of the hide. A couple of minutes later, Will Delacour arrived and decided that they must be watching a species of American yellowlegs. He phoned me at home, but I missed the call as I was out seawatching. He then phoned Derek Julian, who spoke to me on my return, asking for an opinion on the bird's ID.

I managed to get to the hide at around 2 pm. My first impressions on seeing the bird were of a fairly large, long-billed yellowlegs with well-marked underparts, and we all discussed the possibility of it being a Greater. However, at that time I had not seen the bird in flight or heard it call.

We then discussed the features that appeared not to suggest Greater, being very conscious of the justifiable flack that would undoubtedly ensue from the rare-bird-chasing fraternity if we got it wrong, not to mention the potentially huge and unnecessary carbon footprint created by birders setting off from all corners of Britain, armed with news of such a mega. This last consideration undoubtedly contributed to the delay in getting the news out, and I would go so far as to say that it even influenced the identification process.

In the short time that I had spent watching it, I considered the feeding action shown by the bird to be very unlike a typical Greater Yellowlegs, and the size was extremely difficult to gauge with only a Little Egret coming anywhere near 'our' bird.

We were praying for a Redshank to fly in and settle beside the wader for a decent comparison, and it didn’t help that most of the bird's tertials appeared to be missing, denying us a look at the key feature of primary projection beyond the tertials. We should have remembered that Greater moults earlier than Lesser Yellowlegs. The barring and spotting to the underparts did look impressive, although I have seen at least one similarly heavily marked Lesser. The bill appeared to be long and straight, but not as robust as you might expect for a Greater.

Given these doubts, Derek and I left the hide with the reluctant impression that on balance it must be the commoner Lesser Yellowlegs. I tend to rely more and more these days on analysing photos as an aid to identification, and when I arrived home I went directly to my computer to check my photographs for the bill, tibia and tarsus ratios. This quick and simple process overwhelmingly suggested a Greater Yellowlegs!

I phoned Derek immediately, who was independently coming to the same conclusion. Undoubtedly a mistake had been made but, with lessons learned, I’m not at all disappointed in our identification process - given the implications, it was far better to err on the side of caution, but it just took too long for the demanding expectations of some modern birders.

A little later we managed to record the call, and that evening was spent with about 80 very happy birders watching an indisputable Greater Yellowlegs. We could at last relax and enjoy this fantastic long-distance vagrant.

Many thanks again to the finders for giving so many people this unique chance of enjoying a great bird.