Saturday, 14 September 2013

Friday 13th Sept

Mick and I arrived at the reservoir at 05:00 yesterday morning to be met by low cloud and fine drizzle. The rain was forecast to clear throughout the morning so until then a cup of tea was in order until it passed.
After 30 minutes the cloud started to break up so we took to the task of erecting the nets.
A good movement of warblers was soon noted and Chaffinches are now starting to make their presence in good numbers with double figures regularly seen on the disused railtrack all day.
Most warblers ringed were Chiffchaffs and Blackcaps with the Reed Warbler, Sedge Warbler, Garden Warbler, Whitethroat, Lesser Whitethroat and Willow Warbler making up a full cast of the resident breeding warblers.
Ageing Chiffchaffs in autumn is fairly straight forward. The freshness of tail feathers is one criteria used to determine their age. Adults replace their whole tail during a complete moult whilst juveniles usually retain theirs which by autumn become abraided and chipped at the tips. However, it is not uncommon to find juveniles with replaced central feathers which then show a contrast with dull old ones and darker new ones. The picture below shows a tail of a juvenile Chiffchaff with a fault bar across the tail. The central tail feathers have been replaced with much darker and greener edged adult type feathers along with the outer two on the right side of the tail, R5 & R6.
If only they were all this easy!

Juvenile tail with some replaced adult type feathers 


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