23rd January – The Chiffchaff conundrum   Leave a comment

Chiifchaff is an abundant summer breeder and a scarce winter visitor to southern England. A sheltered drainage ditch in Poole has been a regular wintering area for this species. We have had three ringing attempts there this month and have trapped nine Chiffchaffs. One Chiffchaff was ringed (as a first year) at the same site in January 2009, making it close to four years old and also shows winter site fidelity.

A small number of wintering Chiffchaffs appear to be of ‘eastern’ origin, either of race albitenus or even of the Siberian race tristis. These races seem to have different origins, as tristis may have evolved from a Himalayan ‘proto-Chiffchaff’ rather than from western birds and have different calls and song. Unfortunately the boundaries between ‘our’ collybita and Scandinavian and Russian albetinus and between albetinus and tristis seem to be blurred. The different origin and vocalisations of tristis have led to some to consider it a different species, Siberian Chiffchaff, but to be sure you have one you must hear it give the ‘lost chick’ call!

A calling ‘Siberian’ Chiffchaff was present on our first ringing attempt, a good candidate was trapped but on release it was heard to give the typical ‘hoeet’ call of collybita. However later, what was presumed to be the same ringed bird was seen to respond strongly to tristis vocalisations. Can a single bird give vocalisations of both collybita and tristis or is it a hybrid or intergrade between the two?

Today we caught a typical collybita and an intermediate pale bird that may have been a Scandinavian albetinus – neither was heard to call!

We hope to continue monitoring these Chiffchaffs and hope to see if any remain to breed. One bird at least is giving the typical ‘chiffchaff – chiffchaff’ song.

 

A typical collybita Chiffchaff with olive-green plumage and dirty underparts

 

 

This pale Chiffchaff has very pale underparts and in the field might have been considered a candidate for 'Siberian' Chiffchaff but in the hand had some olive green in the upperparts

 

 

This bird trapped on 11 01 12 is our best candidate for a tristis but was heard to give a 'hoeet' call on release. Later it responded to tristis vocalisations

 

Posted January 26, 2012 by gryllosblog in Uncategorized

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