Which of the brown shrikes?
Taken on 15 February 2015 at Lucknow, India
Habitat - Tall grassland on the roadside near a lake.
The group of shrikes earlier lumped into Lanius cristatus as a polytypic species has been split back into three groups exemplified by eastern brown shrike Lanius cristatus (cristatus group), Isabelline shrike (isabelline group) and the western red backed shrike (collurio group), each group having other related member species each with its own specific breeding grounds spread east to west across Eurasia. To confuse matters further, some have even exchanged places! after the discovery that the type specimen for Isabelline shrike itself was misclassified necessitating reassignment of species name as per convention. For more on the classification conundrum look up the following references. The new taxonomy of the "Isabelline Shrike" Lanius isabellinus complex - with notes on racial identification
talks about the recent flux in relation to isabelline shrikeshttp://www.surfbirds.com/ID%20Articles/Isabelline.html+Tim Worfolk
a foremost expert on shrikes talks about the state of the art on classification of brown/isabelline/red-backed shrikeshttp://www.dutchbirding.nl/content/journal/pdf/2000-6.pdf
This shrike seen in the picture has a relatively large head and beak with striking absence of markings on the wings and white rump and rufous tail. The bandit mask is absent in front of the eyes. Although at first glance, the indistinct bandit mark should make one think of Isabelline, the rufous crown and consequent prominence of the supercilium becomes a problem which brings up the possibility of a 1st winter brown shrike. However, brown shrikes, even 1st winter ones (or even the typical isabelline) have highly prominent markings on the wings which are prominently absent here.
This brings up the possibility whether this is the Lanius arenarius (chinese shrike) which is a recently recognized species (hence not there in the field guides) which fits the bill. [Details there in the monograph by Tim Worfolk]. While it is easily recognized and distinguished in its breeding grounds, its wintering areas south are unknown. A good candidate is India but with its absence from the field guides, Lanius arenarius is most likely to be misclassified as either Isabelline shrike or juvenile brown shrike. Expert opinion would be welcome.
Here is a link to a book on shrikes by +Tim Worfolk
but apparently it predates the assignment of Lanius arenarius and doesn't even feature the word in the entire book. http://books.google.co.in/books/about/Shrikes.html?id=xWx7ESWeq2QC