acredula type Willow Warbler 26/08/12

The last bird caught of a rain curtailed ringing session at Longshaw on Sunday proved to be the most interesting. The predominantly white underparts and cold colour to the upper parts made this Willow Warbler really stand out even though I didn't catch a more typically coloured specimen on the same net round for direct comparison. It is not often I reach for my copy of Svensson (Identification Guide to European Passerines) or give the wing formula more than a cursory check but this bird made me do both. Incidently I had caught 2 typically coloured Willow Warblers and 6 Chiffchaffs in the previous net rounds.

The light was very poor because of the impending rain but I managed to get some reasonable photos. The lower breast, belly and under tail coverts were pure white but the area around the vent had a very slight buffish wash, the upper breast had a greyish buff wash forming a band as the throat and chin were a paler off white to pure white. The colour of the upper parts was greyish olive-brown or at least that is my best description.



acredula type Willow Warbler (Phylloscopus trochilus acredula)

 


acredula type Willow Warbler (Phylloscopus trochilus acredula)

There is a degree of overlap in plumage characteristics between the trochilus and acredula subspecies but this bird appears to be outside this overlap area and firmly in the acredula side. This is potentially the first reported acredula Willow Warbler for Greater Manchester.