Isabelline Shrike (Lanius isabellinus) - HBW 13, p. 777

Taxonomy: Lanius isabellinus Hemprich and Ehrenberg, 1833, Gumfuda (= Al Qunfidhah), Arabia.
Thought to form a superspecies with L. collurio and L. cristatus; has in the past been considered conspecific with one or both of those, but recent genetic analyses support treatment as separate species. Degree of reproductive isolation from former relatively low, and mixed pairs and hybrids regularly occur where ranges overlap in SW, W & C Asia. Nomenclature of races recently revised, as true identity of nominate isabellinus had been confused: race arenarius previously treated as nominate until examination of the type specimen of isabellinus (collected on non-breeding grounds in W Arabia) showed it instead to be identical to the form hitherto listed as speculigerus; as a result, form previously known as speculigerus becomes nominate, with name speculigerus as a synonym, while form previously treated as nominate takes the oldest available name applicable to it, arenarius (see page 733). Races form two groups, nominate and phoenicuroides representing one group and arenarius and tsaidamensis the other; these groups treated by some Russian authors as two separate species, but nominate race probably intergrades with arenarius in N China (S Nei Mongol). Proposed race karelini (from S Kazakhstan) included within phoenicuroides. Four subspecies recognized.