miércoles, diciembre 05, 2007

Esta lavandera blanca Motacilla alba, me hizo dudar. Se trata, casi con seguridad, de una lavandera enlutada M. alba yarrellii, un visitante muy escaso en tierras madrileñas, pero quizás subestimado. Pego a continuación el mensaje recibido de un inglés que lleva años controlando lavanderas (gracias a Andy Paterson por su mediación).

Going on the ID paper and birds seen in the field , I would say the photo is an adult female yarrelli.
Based on the following:-
1/ Extensive area of black bib.
2/ Distinctly black nape and crown.
3/ Large white forehead.
4/ Obviously black-centred (not dark-greyish) greater and median coverts.
5/ Back colour appears to be one or two shades darker grey than typical adult alba.
It's not easy, but alba appears to be a grey bird in winter, even the crown is grey over black. Any very obvious black would indicate yarrelli.
I suspect the large flocks of yarrelli at sewage farms hereabouts, will have a fair share of albas amongst them. We have probably missed them for years, but especially with warmer winters (17 C yesterday !!), maybe they are now not bothering to migrate further south.

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