There didn't appear to be any Tree Pipits moving or much else for that matter and there wasn't much moving around in the bushes either. It was a surprise, therefore, to find a Tree Pipit in one of the nets on the second net round but that wasn't one of the 'I don't believe it' moments. The second net round also produced a single Willow Warbler and interestingly it was a new adult. Regular readers of this blog will know that I have been catching more adults than usual this autumn so catching another adult wasn't a huge surprise. When the next Willow Warbler also turned out to be a new adult I simply thought it was just one of those things that can happen by chance and that I would catch some juveniles in subsequent net rounds.
The catching rate was very slow but when the 3rd Willow Warbler of the morning also turned out to be a new adult I did start to think 'I don't believe it' and I may even have said it out loud. The next net round produced yet another adult Willow Warbler and another 'I don't believe it', this time the bird was a retrap that was last caught in April of this year. At that point I still thought I was likely to catch at least a couple of juveniles before I packed up because a catch that only included adults seemed so unlikely as to be unthinkable. When the penultimate net round produced another new adult, the 5th of the morning, it produced another 'I don't believe it' from me. The final net round drew a blank so it was a case of 5 adults out of 5 and not a juvenile in sight!.
I know its not a big sample but to catch 5 Willow Warblers on 9th August and for all of them to be adults is exceptional to say the least. It certainly underscores how unusual the juvenile:adult ratio has been at the site this autumn and I am sure it is a subject I will come back to again at some point.
|Adult Willow Warbler 09/08/17. Four of the five had completed their full moult and the one that was still in moult had nearly finished.|