09 August 2016

Two subspecies of Eurasian Reed Warbler in Saudi Arabia confirmed from DNA

A recent paper on the ‘Mitochondrial phylogeny of the Eurasian-African reed warbler complex’ has confirmed by DNA samples that two subspecies of Eurasian Reed Warbler Acrocephalus scirpaceus occur in Saudi Arabia and birds from the southwest once thought to be African Reed Warbler A. baeticatus are in fact Acrocephalus scirpaceus avicenniae. The other subspecies is Acrocephalus scirpaceus fuscus that occurs in central Saudi Arabia (Riyadh - DNA) and Eastern Saudi Arabia (Jubail - ringing details). The paper mentioned above says fuscus is a well-supported clade containing all samples from Kazakhstan and several from Saudi Arabia and Israel, where four samples from Lake Kenneret, collected some time later than 21 May in 1995, may have been local breeders. The western-most sampling locality in the presumed breeding range are Astrachan and Azerbaijan, suggesting that the ranges of fuscus and scirpaceus abut somewhere between the Black and the Caspian Seas. The second clade was avicenniae containing the holotype of avicenniae from Eritrea and samples from breeding populations in Saudi Arabia (Al Shuqaiq), but also a sample from Kenya originally attributed to fuscus. As the latter was obtained away from the breeding grounds, misidentification is a possibility. Most probably this sample represents a migrant from the Red Sea mangrove population. The range of avicenniae is generally believed to be confined to mangroves bordering the Red Sea, but has recently been extended to reach Egypt (Hering et al., 2011a).  The papers records from Lake Kenneret inland Israel, and the observations by Morgan (1998) and Hering et al. (2009, 2011b), imply that this taxon may have a larger distribution and wider choice of habitats than previously known. I have trapped and ringed both these subspecies in Saudi Arabia with photos below of both types and have blood samples from Either Mangroves and Al Qahma Mangroves in the southwest. These blood samples will be tested soon to find out where they lay in relation to the other birds sampled, but will almost certainly be Mangrove Reed Warbler Acrocephalus scirpaceus avicenniae which is what was assumed when trapped and measured.
Acrocephalus scirpaceus fuscus
Caspian Reed Warbler Acrocephalus scirpaceus fuscus
Acrocephalus scirpaceus avicenniae
Mangrove Reed Warbler Acrocephalus scirpaceus avicenniae