7 Mar 2015

Long-tailed Shrike still present and moulting – Dhahran Hills golf course

On 5 March I went to the golf course to have a quick look at the pond and see if anything else was about. I saw a shrike on arrival but it was a male Turkestan shrike rather than the Long-tailed Shrike that had been seen in the area two weeks before. Whilst looking around I saw another shrike very briefly looking very much like the Long-tailed Shrike but lacking the long tail feathers of this species and appearing more warm on the upperparts than the previous bird. As the bird had a short tail I looked into the moult strategy of Long-tailed Shrike with the help of Tom Worfolk. The bird in Dhahran appears is an adult and BWP & Panov says (with ref. to migratory ssp. erythronotus): Adults have complete moult before autumn migration. Adult Pre-breeding moult timing and extent has not been fully established, although some from India in March–April, had head, body, tail, part of upper wing-coverts, and all tertials new. Juveniles as most other shrikes, rapid partial post juv. moult, maybe followed in winter/spring by complete moult? It thus appears that out Long-tailed Shrike is still about but now in the process of regrowing all of its tail feathers. This suggests it will stay around for a few more days until its tail moult is complete. As mentioned previously the sub-specific identity of the bird is not straightforward although erythronotus, breeds in the Palearctic, where it is strongly migratory although the lack of rufous extending onto the scapulars is not normal for this subspecies and the amount of white over the eye seems excessive also.  All extralimital Western Palearctic records and all records from the Middle East have been assigned to this sub-species. The first record for the UK at Howmore, South Uist, Western Isles, 3rd and 4th November 2000 encouraged the BOURC, to check museum skins, and they concluded that the white line above the eye and the lilac tinge to the grey mantle are features more typically associated with the form caniceps, which is considered to be largely resident in southern and western India. This is the other subspecies I considered for the Dhahran bird. Examination of a selection of specimens available at the National Museums of Scotland demonstrated that erythronotus can show individual variation, but rarely show any white above the eye. The limited number of specimens of caniceps similarly showed individual variation, but the paler grey mantle and white above the eye were apparent on most individuals. The paper also says, as I also mentioned in a previous post on the Long-tailed Shrike, that the most likely explanation is that greater individual variation exists within erythronotus, and that this can lead to some birds showing some characters suggestive of caniceps. To complicate matters further there is clinal variation between adjacent mainland forms and many individuals cannot be confidently assigned to any given subspecies. This added information has not helped clear up the issue but the bird sis most likely to be erythronotus as they are strongly migratory and caniceps is not.
March 5
February 18

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