Saturday, 7 April 2012

Thayer's Gull in Lincolnshire

Yesterday I went down to Lincolnshire to twitch the Thayer's Gull with Richard Stephenson and Chris Bell, I was the only one who had not seen the species before and so was keen to see it. News broke about this bird midweek and since then some photos have emerged and have shown it to be a generally handsome bird that exhibits all the features that should be shown by a Thayer's Gull. Kumlien's Gull are thought to be either closely related to Iceland Gull or Thayer's Gull. Genetic sequencing and further research would need to be done before assigning Kumlien's to be a subspecies of either Iceland Gull or Thayer's Gull.

We arrived around about 11.15ish and made our way for the location where the bird had last been seen some 5 minutes before our arrival. The bird had been showing well but on our arrival we were informed it had flown and had not been seen in the field since. We were not too concerned as we knew it would be nearby somewhere as it had been communing between a few fields in the general area. We then headed back to a location where the bird had apparently flown to, it took a short while but I eventually picked the bird out flying up out of a ploughed field, I managed to get most of the crowd on it as it gained height and floated it away. A few minutes later it returned and then the gulls moved on over toward the country park. We checked the country park next but there was no sign at all, a Caspian Gull was claimed but many present could not see the bird being claimed amongst the 100 or so present. It was then time for some lunch and a few rather good jokes, was good to meet up with Alan Whitehead again and Tom Middleton put in a brief appearance, before moving off strongly West back to Sheffield.

I was less than hopeful when most of the Gulls disappeared mid afternoon, I started to be rather happy about seeing the bird late morning as it was looking like it had done a runner. However at around 3 it was found close to the field I first saw it in and it performed very well in both flight and on the deck, it allowed for some study. I had never seen Thayer's Gull before and had no previous experience with the species but it was apparent it was a fairly obvious bird. Most Thayer's Gulls do tend to be a lighter shade of brown than this individual and I learnt that apparently the darker birds comprise something like 20% of the population and so are rare, so in other words its a mega rare gull in a rare plumage. Everyone is a winner. The bird was quite striking and here are some things to consider about the birds plumage:
- The head was small and fairly pear shaped.
- The bill was long and all dark and made up quite a lot of the general head size of the bird.
- Overall a very dark chocolate brown bird.
- Inner primaries a nice silver colour which formed a window on the inner primaries.
- Scapulars solidly dark with white fairly broad white fringes.
- Solidly dark tail band.
- Secondaries dark and contrast with the rest of the birds upperwing being nearly uniform with the tail band.
- Fairly heavy and dense barring on both the upper and undertail.
- At rest the primaries were easily the darkest part of the birds plumage, in flight this forms part of the outer primaries and this is particularly obvious in flight as well as on deck.
- Upper rump contrasts well with tail and the rest of the upper body, much paler than the rest of the birds plumage.

Overall a very nice bird and well worth the visit, glad I went and a nice bird. Learnt a lot and look forward to hearing what the committees are going to do with it. Will they split it and follow suit to what other committees do? Let's wait and see.

(Thayer's Gull - © Andrew Kinghorn)

Until next time, Foghorn out!

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