Friday, 30 November 2012

The fallacy of the "southern grey shrike"

Yesterday while birding I came across one "grey shrike" and several "red-tailed shrikes" at Al Hayer. I was reminded once again how difficult identification and classification of middle eastern shrikes is.

The grey shrike was aucheri although I often find it difficult to separate from pallidirostris. The black bridge across the bill and the ochre-buff wash to the underparts is often a good indication of aucheri  as usually (but not always) is the general shade of greyness. In the end, I sometimes have to  fall back on the deposition of the white on the wings if these indicators don't help.

aucheri yesterday 

Note, I am deliberately not naming aucheri as southern grey shrike and pallidirostris as steppe grey shrike.

back view of the same grey shrike

As many of you might know, recent DNA work published in 2010 in Molecular Phylogenetics and Evolution pretty much concludes that the southern grey shrike is a genetic fallacy. Indeed Svensson's Birds of Britain and Europe follows its lead from this DNA work. In this largest selling guide, Southern grey shrike is divided into Iberian grey shrike (clade D2), desert grey shrike (clade B) while aucheri and buryi - the breeding shrikes are back into the great grey shrike (clade A) camp. 

part of the map of grey shrike clades from Olsson et al 2010

Furthrmore pallidirostris is in clade A too. They say they don't know yet where clades A1, A2 and A3 should be split but there isn't enough data to do this yet. So taking this to its logical conclusion pallidirostris is a great grey shrike too. 

I think the DNA evidence is unquestionable. What seems to have perpetuated the idea of southern grey shrike in our part of the world is its inclusion in the 2011 edition of Birds of the Middle East which didn't follow Olsson's  (and Svensson's) lead.  I don't know whether this is because they are waiting for the "official word". 

Red-tailed shrikes are also difficult and I don't believe as much DNA work has been done.

In the field I have day-to-day identification problems. In winter we have very large numbers stay near Riyadh and some can be a real headache.

female adult Daurian shrike

Male adult male red tailed shrike are generally easy to separate but females are more difficult and some first winters are near impossible (for me anyway)!

The bird above is an adult - note the white flash on the wing. The lack of a supercilium and no obvious(?) rufous crown, and dirty underparts tilts me towards Daurian shrike

Then it just gets more difficult. Two more birds I saw yesterday I ended up calling first winter Turkestan shrike but not without angst.

first winter Turkestan shrike

I went for Turkestan shrike with the above above because I managed to get an angle where you can see a rufous crown.  

I went for Turkestan shrike for the second one too because I originally spent so much time on it as I lived in a momentary fantasy that it might be a brown shrike. And Turkestan shrike are a lot closer to brown shrike than Daurian shrike.

a second juvenile Turkestan shrike

I don't particularly enjoy looking at shrikes but I cant really avoid them.

PS. I fixed a bug which meant many viewers couldn't watch the partridge videos in the blog from two days ago. Try it now! It should work.

1 comment:

  1. I share your pain Rob, i have just returned after a couple of weeks mooching around in Maroc (again). I found Shrikes in the interior with paler plumage and large White wing flashes and darker 'greyish' birds on the coast with smaller wing flashes but also found the opposite in each habitat so i do'nt really know what i've supposed to have seen......

    All good fun -

    ATB Laurie -