15 December 2013

Arabian Scops Owl Otus pamelae – A new Arabian Endemic

Keonig (2008) split Arabian Scops Owl Otus (senegalensis) pamelae as a distinct species from African Scops Owl O. s. senegalensis but recent work (Pons et al 2013) has shown African Scops Owl Otus senegalensis pamelae, represents a very distinct lineage and is well differentiated phylogenetically, morphologically and vocally from O. s. senegalensis. As a result it has been recommend to elevate it to species status, as Arabian Scops Owl Otus pamelae. The reasons for this are this southern Arabian taxon is highly divergent from African senegalensis (uncorrected-p mitochondrial genetic distance = 4%). The song of pamelae is very different from that of Eurasian Scops Owl O. scops and Pallid Scops Owl O. brucei but more similar to that of African Scops Owl O. senegalensis. It nevertheless differs from the latter’s song in being higher pitched, sounding ‘scratchier’ and having more prolonged notes; the song sounds two-parted, due to the much quieter first note (G.M. Kirwan & R. F. Porter pers. obs., Keonig et al. 2008). In terms of biometrics, results clearly suggest that pamelae is longer winged and longer legged than mainland African populations of senegalensis. In comparison with populations of O. senegalensis in continental Africa, Arabian pamelae is distinguished in being paler overall, with less distinct streaking over the underparts and a less obvious whitish line on the scapulars (Keonig et al. 2008). Arabian Scops Owls possess several diagnostic genetic and phenotypic characters and it is therefore consider the most appropriate taxonomic treatment is to recognize Arabian Scops Owl as a species Otus pamelae, and not as a subspecies of O. senegalensis as it was originally described based solely on morphological data. This change means that Arabian Scops Owl becomes a new Arabian endemic, found in South-west Saudi Arabia, South-west Yemen and north-east to southern Oman and African Scops Owl Otus senegalensis is now no longer found in Arabia but instead occurs in parts of Ethiopia, Eritrea & Somalia.

Note: Birds seen and heard in Daallo Forest, Somaliland, sound very similar to the scops owls of South-west Arabia which are now considered to be a separate species (see above). Their call is noticeably different from that of African Scops Owl O. senegalensis, which is what they were previously considered to be. The identity of the Daallo birds may not be resolved until their DNA can be tested; they could be Arabian Scops Owls but it is also possible that they may prove to be a distinct taxon (Birdquest 2012).

Jean-Marc Pons, Guy M. Kirwan, Richard F. Porter & Jerome Fuchs (2013). A reappraisal of the systematic affinities of Socotran, Arabian and East African scops owls (Otus, Strigidae) using a combination of molecular, biometric and acoustic data. Ibis (2013), doi: 10.1111/ibi.12041
Keonig, C., Weick, F. & Becking, J.-H. 2008. Owls: A Guide to the Owls of the World, 2nd edn. London: Christopher Helm.
Redmond, N. 2012. Birdquest Tour Report: Djibouti & Somaliland 9-27 September 2012.