27 January 2009

This intriguingly brown/grey and white Chiffchaff has been present at Clennon Valley since November last year. Unfortunately, it has not positively been heard to call – one of the best ways to separate the various Chiffchaff types.

The current review being undertaken by BBRC has come up with some good guidelines for separating a classic Siberian tristis Chiffchaff (see Chiffchaffs) but there are many other birds that remain difficult to identify racially.

This bird is a tricky one! Following the BBRC identification criteria for tristis Chiffchaff, this is how the Clennon Valley bird fits:

• Absence of olive in the crown and mantle – Yes
• Absence of yellow away from the underwing – Yes
• Presence of a grey-brown or pale brown hue in the upperparts – Slightly
• Presence of warm buff in the supercilium and ear-coverts – Slightly
• Presence of buff at the breast-sides/flanks – No, very white
• Very black-looking bill and legs – No, very brown almost pink!
• A thin, piping near-monosyllabic Bullfinch-like or Dunnock-like call – Not calling
• A song markedly different from western Chiffchaff's – No song

Overall in plumage this Clennon Valley bird is pale with muted colours, suggesting a northern/eastern type tristis, abietinus or fulvescens. But can these Chiffchaff types be as variable in plumage as collybita, our Western European Chiffchaff? If so, it is probably impossible to classify – but still a very striking bird to look at!

Many thanks to John Lee for getting such a good photo and letting us use it!

Chiffchaff subspecies – Clennon Valley – © John Lee – 20 January 2009