The weather forecast kept changing & we almost cancelled the session due to impending rain showers....but decided to give it a go. We'd originally planned to go to Colyford Common at the far end of the Wetlands, but changed to the Willows area so we'd have the pond dipping shelter for cover if needed.
We put up 6 nets, and almost immediately caught a Cetti's Warbler. They're quite difficult birds to age, but testing out Robin's new guide 'Identification Atlas of the Continental Birds of Southwestern Europe' by Blasco-Zumeta & Heinze, we aged it as an adult (age code 4). The guide is excellent, using a lot of the photos & information that's been available for some time online at Blasco-Zumeta.com. The bird was aged as an adult due to the lack of a moult limit in the wing, the broad rounded tail, the lack of tongue spots and the single generation of feathers in the Undertail Coverts (sometimes the 1st year birds can retain some old feathers, particularly the longest ones, which will be worn, a different colour & without clear white tips).
 |
| Cetti's Warbler |
 |
| Cetti's wing |
 |
| Cetti's tail |
We then had a bit of a surprise as the first proper round produced 21 birds, which included a flock of 6 Long-tailed Tits. Adult Long-tailed Tits undergo a complete post-breeding moult, and quite unusually, the post-juvenile moult of this years birds is also complete. Therefore, if the birds have finished moulting, it's impossible to age them. This was the case with all 6 birds, although one of them was the only re-trap of the day, having been ringed by myself on 17/10/23 in the same area. At the time, the bird had already completed its moult so I was unable to age it, therefore we only know that the bird is at least a year old.
There were also 8 Chiffchaffs caught in the round, most of which were immature, having been hatched this year. It's often possible to spot the immature birds using the presence of unmoulted old Greater Coverts as shown below. The outer Greater Coverts which would have been grown in the nest have a paler fringe & browner centre than the newly grown inner feathers which have a brighter fringe & darker centre. Chiffchaff tail feathers can also be used to age the bird as the juvenile feathers tend to be browner, more pointed & tatty than the newly grown feathers. In the photo below, the juvenile central tail feathers have been replaced.
 |
| Chiffchaff |
 |
| Chiffchaff wing |
 |
| Chiffchaff tail |
The last bird of the day was a Robin, which had a much more obvious moult limit in its wing. The outer old Greater Coverts (OGCs) have a chocolatey background colour & large pale 'thorns'. The new inner Greater Coverts are more olive & have no thorns.
 |
| Robin wing |
We did have a few minutes of sunshine during the session, but at about 10 the rain started in earnest & we packed up.
 |
| The Team in the sunshine! |
Ringed | Re-trapped | |
Blackcap | 4 | |
Blue Tit | 2 | |
Cetti’s Warbler | 1 | |
Chiffchaff | 12 | |
Long-tailed Tit | 5 | 1 |
Robin | 1 | |
Wren | 2 | |
27 | 1 |
