19 August 2012

Southern Grey Shrike but which sub-species? - Dhahran Hills

I saw a Southern Grey Shrike in Dhahran in April and managed to get a few photographs of the bird. I have seen quite a few birds in the last year and although not common have seen them throughout the year, so assume they are resident. All the birds I have seen look similar to the ones in the photos shown here, which are of two different birds (bird two in last two photographs) seen at different sites within Dhahran. ‘Shrikes – A Guide to the Shrikes of the World’ (Lefranc & Worfolk 1997) does not show Southern Grey Shrike as occurring in the Eastern Province of Saudi Arabia on their map, but birds certainly do occur in this area, although possibly not too much further north as they there are only two records from Kuwait.

Lanius excubitor aucheri breeds in Arabia, eastern Egypt, norhern Sudan, Israel, Iraq & Iran. Lanius exubitor elegans breeds most Sahara and north Africa and Egypt west of the range of aucheri. This suggests that birds from the Saudi Arabian region are aucheri , with it being a very common & widespread breeding resident that is noted on passage and as a winter visitor in the United Arab Emirates. The bird I saw looks like a cross between elegans and aucheri, but closer to elegans in plumage, especially the white patch in the wings and the white under-parts colour, lacking the grey wash of normal aucheri. Although the black reaches over the bill, it is more restricted than drawings of aucheri I have seen and seems to fit elegans better. The birds do not appear to be palidirostris as the black goes over the bill, the black on the lores appears too extensive and the white of the under-parts to clean, not pinkish washed. The bill is completely black and this would not be expected in a palidirostris which normally shows a pale horn coloured area on the bill. There is a possibility of these birds being a pale type aucheri. In Sinai, Negev & parts of central Israel there is a continuous intergrading population between elegans & aucheri, beginning in the eastern desert of Egypt (Shirihai - Birds of Israel 1996) so maybe it s something like this? Any ideas or suggestions on where these birds fit in the Southern Grey Shrike complex would be welcome.  

Race elegans has a very thin, often absent, line of black feathers on the forehead and a moderate white line above the facial mask on most birds. This is unlike the prominent / broader black frontal mask and much reduced or absent white line of aucheri. In elegans the mantle is paler ashy-grey, the under-parts cleaner rarely with any hint of pink or grey and has an extensively white tail with T6 entirely white apart from a partly dark shaft. The secondaries are also completely, or nearly so, white on the inner webs and has a larger white area on the scapulars, as well as a larger white wing panel beyond the upper primary coverts (15-30 millimetres). In aucheri there is always a varying degree of grey wash to under-parts, the mantle is always darker and the tail is more black with T6 having a black base on the inner web and a broader and more protracted dark area on the shaft. In aucheri the secondaries are largely dark grey or just partly white and the white area beyond the upper primary coverts measures only 7-18 millimetres (Shirihai - Birds of Israel 1996).