First Calendar Year at Castricum
There have already been several Isabelline Shrikes this autumn- some creating lively debate about whether there are one form or the other. We might look at a few of the others. First off this very interesting one.
OK I know it might be pushing it to put a definite name to it. This bird has caused some head scratching. There will hopefully be definitive DNA analysis and claiming it as a ‘definite’ Turkestan – well wouldn’t it just be better to keep you’re head down? To me it’s very similar to one of the individuals we feature in The Challenge Series: AUTUMN – here on Flamborough (at Buckton). That bird was also identified as a 1cy Turkestan.
Making mistakes. Trying and sometime getting it wrong- but still pushing the boat out and having a go. It’s what it’s all about!
So enter Hans Schekkerman, with photos from Cees de Vries and Luc Knijnsberg (and thanks to them). I understand after more views they are mostly pro-Turkestan. Here’s what Hans wrote on the first day:
Today (13th Nov) a 1st winter Isabelline shrike was trapped and ringed at Castricum, Netherlands. A set of photo’s by Cees de Vries can be found at http://waarneming.nl/waarneming/view/95333564 .
Here is a translation of the comment I posted with the record:
This species is as difficult in the hand as in the field! … First-winter with completely juvenile wing … In the sunlight it appeared to me more like Daurian, but in the shadow it reminded more strongly of Turkestan (Red-tailed).
Pro-phoenicuroides: (1) mask rather dark and contrasting (but with some gingery wash); (2) clear off-white supercilium (though extending well behind eye only on the right side), with some buffy wash only above the lore; (3) rather stronk dark barring on crown, rump, uppertail-cov and even some on lower mantle; (4) underparts mainly whitish, contrasting rather strongly with upperside.
Pro-isabellinus: (5) there was some clear buffish/orange wash on flanks (particularly on those feathers with brown chevrons) and also on the central belly; (6) this wash faintly continued up the breast-sides and onto the cheeks, that were not entirely white even directly under the mask; (7) tail fairly bright rufous with only a little bit darker centrals and not much darkening distally; (8) in sunlight, warmer ‘gingery’brown tinge to upperparts (almost invisible in shade).
Centres of juv median coverts were neither whitish nor orange but dark brown, with even darker subterminal line and warm-brown edge.
Any opinion on this bird would be greatly appreciated.
Best wishes, Hans Schekkerman”
So I say the DNA will make it a Turkestan- phoenicuroides- the rarer of the two regularly identified forms of ‘Isabelline Shrike’ which turn up in NW Europe. It’s not the easiest example and in some of the photos- brighter sunlight causes it to morph into something looking a little more akin to a Daurian Shrike. The Buckton bird did exactly the same - morphing in sunlight. I think the flat ‘overcast’ light depicts it more accurately.
Most of the features fit the details described and illustrated for Turkestan in The Challenge Series: AUTUMN.
What do you say it is? Place yer bets.
The variety of photos in different light shows how the plumage tones ‘morph’ to see degree. Overcast flat light is best.
Thanks especially to Grahame Walbridge for much excellent input on this and others Issy Shrikes.