Chiffchaffs wintering in Kuwait : which subspecies?
Chiffchaff, Al Abraq, Kuwait, December 2nd 2013
Certain Chiffchaffs wintering in Kuwait have enigmatic plumage and calls. The crown and mantle are olive-brown while the underparts are rather pale, with relatively limited yellow streaking. However, there are evident olive fringes to the flight-feathers. The plumage lacks the rusty-buff or 'tan' suffusions typical of Siberian Chiffchaff. They have a distinctive call, which starts on an even pitch, like tristis, but then rises and then falls, the sonogram having the shape of a 'hook' tipped on its side (see below).
Fig. 1. Call of Chiffchaff ay Jahra, Kuwait, November 2013
The call can be heard here ►. In quality, the sound is rather in-between that of nominate collybita and Siberian tristis, with the terminal fall in pitch relatively weakly discernible to the ear. The subspecies involved is subject to a great deal of speculation, with suggestions including menzbieri but caucasicus also seems to be a possibility. The 'hooked' shape does not match any of the sonograms of Chiffchaff races published by Helbig et al. (1996) and repeated by Clement et al. (1998). However, the first call illustrated in section 'k' for caucasicus in Helbig et al. closely matches the flat opening and the rising pitch at the midway point. It apparently lacks the terminal downward turn (but conceivably this been truncated in the recording or subsequent processing of the sonogram, as the downstroke is abrupt and has less impact than the rest of the call).
See <here> for sonograms and discussion of Chiffchaffs in the Elborz mountains of Iran, a region spanning the ranges associated with caucasicus and menzbieri. The Iranian birds are of somewhat similar appearance to the Kuwaiti Chiffchaffs but with a greyer ground-colour to upperparts and distinctly white underparts, yellow being restricted to isolated streaks. They have a predominantly flat, rather tristis-like call, with just a very shallow rise and fall, A sonogram is below.
Fig. 2. Call of Chiffchaff at Kiaser, Elborz Mountains, Iran, April 2017
In Azerbaijan, on March 19th 2012, Timo Janhonen recorded Chiffchaffs with a call comparable to those in Kuwait, with an evenly pitched ('flat') opening followed by a terminal arch . The recording is available <here>.and photos <here> on Tarsiger. The breeding form in Azerbaijan is caucasicus but the early date does not confirm birds established on territory. There were several such birds but Timo Janhonen states (in lit.) that they were in lowland shrubberies and meadows by the Caspian Sea (rather than the forest) and, consequently, it is impossible to know whether they were arriving near their breeding grounds or were migrants en route farther afield. Timo also noted a very similar call <here> on xeno-canto, recorded in Azerbaijan in January 2015 by Steve Klasan, so individuals with this call apparently winter in the region.
Fig. 3. Calls of Chiffchaffs from Azerbaijan, March 2012
(left), Azerbaijan January 2015 (centre) and Kuwait, November 2013 (right).
(Azerbaijan sonograms prepared from recordings by Timo Janhonen (left) on Tarsiger and Steve Klasan (centre) on xeno-canto.)
Many thanks to Timo Janhonen for providing recordings and other useful data from Azerbaijan and Antero Lindholm for discussions of the Chiffchaffs found in Georgia and adjoining regions.
CLEMENT, P., HELBIG A.J & SMALL, B. 1998. Taxonomy and identification of chiffchaffs in the Western Palearctic. Brit. Birds 91: 361-376.
HELBIG, A.J., MARTENS, J., SEIBOLD, I., HENNING, F., SCHOTTLER, B. & WINK, M. 1996. Phylogeny and species limits in the Palearctic Chiffchaff Phylloscopus collybita complex: mitochondrial genetic differentiation and bioacoustic evidence. Ibis 138: 650-666.