1 Mar 2015

tristis and abietinus Chiffchaffs caught and ringed – Sabkhat Al Fasl

Whilst ringing at Sabkhat Al Fasl on 23 January 2015 we caught three Chiffchaffs with two appearing to be the normal abietinus types we catch, and one a rather duller paler looking bird recalling Siberian Chiffchaff tristis, that has just been elevated to full species status in the latest OSME regional list ORL version 3.0 and IOC4.1 list repurposes splitting. The Siberian Chiffchaff is shown below in the top photograph and shows a bird with a brown component to the plumage that is critical in the identification process as the upperparts often have a somewhat ‘tan’ appearance. The bird showed the right shade of brown in the upperparts and the buff wash on the breast and flanks with slight ‘additional’ yellow and olive compatible with ‘fulvescens’, generally treated as a western form of tristis, though it remains to be fully determined whether or not it’s appearance results from limited introgression of abietinus genes (Alan Dean pers comm). The main criteria for identification of Siberian Chiffchaff are as follows: Absence of olive in the crown and mantle with a grey-brown or pale brown hue in the upperparts. There is an absence of yellow away from the underwing with warm buff in the supercilium and ear-coverts and some buff at the breast-sides/flanks. The bill and legs often appear very black but this feature is variable. If the bird calls the most distinct call is a thin, piping monosyllabic ‘peep’. The Siberian Chiffchaff is a vagrant to Saudi Arabia with this bird being the first properly documented record for the Country. Records are rare from Kuwait, Qatar and the UAE but they are regular wintering birds in Oman. The second photo shows an abietinus type applying that designation in its broader sense. Identity of Chiffchaffs in the Middle East is very complicated with Mountain Chiffchaffs nearby, which look quite like tristis, and a series of taxa with intriguing combinations of abietinus or intermediate plumage but tristis-like calls (the brevirostris/caucasicus/menzbieri group), diagnosing Chiffchaffs can be a demanding exercise. I sent these photos to Alan Dean who is an expert on many things including Chiffchaffs and he agreed with my identifications and I would like to thank Alan for his very helpful comments on these birds.
Siberian Chiffchaff - tristis
Siberian Chiffchaff - tristis
Common Chiffchaff - abietinus
Common Chiffchaff - abietinus

2 comments:

  1. A bird in the hand is probably the only sure way to ID. I would not like to attempt to differentiate in the field :-)

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    1. Mike

      Even in the hand they present a challenge. In the field the call is they way to go for identification along with plumage for tristis.

      Jem

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