Tracing the colonization history of the Indian Ocean scops-owls (Strigiformes: Otus) with further insight into the spatio-temporal origin of the Malagasy avifauna

摘要: The island of Madagascar and surrounding volcanic coralline islands are considered to form a biodiversity hotspot with large numbers unique taxa. origin this endemic fauna can be explained by two different factors: vicariance or over-water-dispersal. Deciphering which factor explains the current distributional pattern given taxonomic group requires robust phylogenies as well estimates divergence times. lineage Indian Ocean scops-owls (Otus: Strigidae) includes six seven species that portions Comoros Seychelles archipelagos; little is known about limits, biogeographic affinities relationships each other. In present study, using DNA sequence data gathered from loci, we examine history scops-owls. We also compare timing colonization times already proposed for other bird Our analyses revealed do not monophyletic assemblage: Otus insularis genetically closer South-East Asian O. sunia than Madagascar. Pemba Scops-owls pembaensis, often closely related to, if conspecific rutilus Madagascar, instead African mainland senegalensis. Relationships among taxa unresolved, despite analysis over 4000 bp, suggesting diversification burst after initial event. highlight one case putative back-colonization an ancestor (O. sunia). date estimates, Bayesian relaxed clock method, suggest all these events occurred during last 3.6 myr; albeit were synchronous, pembaensis diverged senegalensis 1.7 mya while Comoro their continental sister-group mya. our coincide lineages. occurrence multiple synchronous scops-owls, at time when faunistic exchanges involving was common result lowered sea-level would have allowed formation stepping-stone islands. Patterns emerged are: 1) star-like concerning order 2) high genetic distinctiveness taxa, reinforcing recognition distinct species.