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

Abstract

We investigated phylogenetic relationships among Otus scops owls from Socotra Island, the Arabian Peninsula and East Africa using molecular, vocalization and biometric data. The Socotra Scops Owl Otus senegalensis socotranus, currently treated as a subspecies of the African Scops Owl Otus senegalensis, is more closely related to the Oriental Scops Owl Otus sunia and to the endemic Seychelles Scops Owl Otus insularis. Considerable mitochondrial genetic distance and significant morphological differentiation from its two closest relatives, as well as its distinctive vocalizations compared with O. insularis, strongly support recognition of Socotra Scops Owl as a full species. Unexpectedly, two taxa from the Arabian Peninsula, Pallid Scops Owl Otus brucei and African Scops Owl Otus senegalensis pamelae, represent very distinct lineages; O. brucei is basal to a clade that includes taxa found in the Indo‐Malayan region and on Indian Ocean islands. In contrast, O. s. pamelae occupies a well‐supported basal position within a clade of continental Afro‐Palaearctic taxa. The uncorrected‐p genetic distance between O. s. pamelae and its closest relatives (other populations of senegalensis from mainland Africa) is c. 4%. As O. s. pamelae is also well differentiated phylogenetically, morphologically and vocally from O. s. senegalensis, we recommend its elevation to species status, as Otus pamelae. Among mainland African O. senegalensis subspecies, Ethiopian populations appear to represent the most divergent lineage, whereas other lineages from Somalia, Kenya and South Africa are poorly differentiated. The large genetic distance between the Ethiopian haplotype and other African haplotypes (3.2%) suggests that the Ethiopian Otus may represent a cryptic taxon, and we recommend that more individuals be sampled to assess the taxonomic status of this population.

Evolutionary distinctiveness and historical decline in genetic diversity in the Seychelles Black Parrot Coracopsis nigra barklyi

“…Indeed, the two subspecies on Madagascar clustered together morphologically and genetically, indicative of a relatively recent gene flow that could have been facilitated by their adjacent (and in some areas, sympatric) distributions. Similar patterns of evolutionary distinctiveness have also been observed in a number of other endemic bird species including the Seychelles Kestrel Falco araea (Groombridge et al 2002), the Seychelles Paradise Flycatcher Terpsiphone corvine (Bristol et al 2013a) and the Seychelles Scops Owl Otus insularis (Pons et al 2013). The mean mtDNA divergence between C. n. barklyi and C. n. sibilans of 3% was higher than that observed between the Mauritius Parakeet Psittacula echo and the Indian Ring-necked Parakeet Psittacula krameri manillensis, which are classified as two separate species (Groombridge et al 2004, Kundu et al 2012.…”

Ancient DNA reveals the origins, colonization histories, and evolutionary pathways of two recently extinct species of giant scops owl from Mauritius and Rodrigues Islands (Mascarene Islands, south‐western Indian Ocean)

“…Both M. sauzieri (Mauritius) and M. murivorus (Rodrigues) are confirmed as deriving from the wide‐ranging genus Otus ( sensu stricto , i.e., comprising only Old World representatives; König & Weick, ). Furthermore, both extinct species belong to the Indo‐Malayan/Indian Ocean clade (Figure ), as do the extant Otus species from Comoros, Madagascar, Seychelles, and Socotra Islands (see Fuchs et al., ; Pons et al., ). Within this group, the two Mascarene taxa are not related to O. insularis (Tristram, 1880) from the Seychelles, but belong to the Comorian‐Malagasy radiation.…”

“…With respect to O. pauliani , our results correspond with those obtained using CytB by Roulin, Burri, and Antoniazza (). In another study (Pons et al., ), based on two mitochondrial markers (ND2, ND3) and two nuclear introns (MB intron‐2 and TGFb2 intron‐5), O. pauliani and O. moheliensis were placed in a polytomy with the remaining regional taxa (western insular Indian Ocean Otus ), grouped with limited support. We therefore consider that grouping O. pauliani with O. rutilus and M. sauzieri is a plausible result from our data set.…”

“…Scenario inferred for the two minimal waves of colonization of the islands of the western Indian Ocean, leading to the extant and extinct insular endemic scops owls, by the continental ancestral lineage (leading to O. sunia ). In near‐chronological order: 1, colonization of the Philippines (leading to O. mirus and O. longicornis ), probably in the early Pliocene (see text for discussion of divergence ages); 2, first colonization of the SW Indian Ocean islands, ca 3–4 Ma, and concomitant “star‐like” differentiation of branches on Rodrigues ( O. murivorus ), Mohéli ( O. moheliensis ), Mayotte ( O. mayottensis ), Anjouan ( O. capnodes ) and one branch leading to (3); 3, colonization from Madagascar of Mauritius and Réunion later than 3–4 Ma (leading to O. sauzieri and O. grucheti , in an undefined order), and of Grand Comoro ca 0.5 Ma (leading to O. pauliani ); 4, colonization of Seychelles and Socotra by O. sunia lineage (2nd Indian Ocean colonization, ca 1 Ma), leading to O. insularis and O. socotranus (Fuchs et al., ; Pons et al., ); 5, differentiation between the two subspecies of O. rutilus on Madagascar (from lineage in (3)). Grey hatched areas: present‐day distribution of O. sunia (including breeding and wintering areas).…”

“…Furthermore, their evolution may have included an increase or decrease in body size, or even invariance. In order to answer these biogeographical and evolutionary questions, we analysed ancient DNA (aDNA) fragments from subfossil remains of each of the three Mascarenotus species to determine their position among strigid owls, including extant Otus species of the Indian Ocean region (Fuchs et al., ; Pons, Kirwan, Porter, & Fuchs, ).…”