MOLECULAR-DATA CONFIRMS THE SPECIES STATUS OF THE CHRISTMAS ISLAND HAWK-OWL NINOX-NATALIS

DNA sequences from the mitochondrial ND2 gene were used to assess the taxonomic status of the Christmas Island Hawk-Owl Ninox natalis. Seque nce variation was examined across 17 specimens representing 9 species and subspecies within the genus Ninox. The comparisons revealed a corr elation between taxonomic level and genetic divergence with a clear se paration between the levels of sequence divergence observed in compari sons involving individuals, subspecies and species. These observations provided strong endorsement for the use of DNA sequence data to asses s the taxonomic status and phylogenetic relationships of N. natalis. L evels of sequence divergence recorded between the three forms of the N . squamipila complex examined (squamipila, hypogramma and natalis) ran ged from 4.0% to 4.8%. These were comparable to the levels of divergen ce observed between obviously distinct species such as N. rufa and N, strenua (5.4%) and were consistently greater than observed among subsp ecies within the monophyletic N. novaeseelandiae complex (1.5% to 2.3% between novaeseelandiae, leucopsis and undulata). The genetic distinc tiveness of all three forms of squamipila was also apparent from phylo genetic analysis of the data. Distance and parsimony methods both fail ed to identify any of the three forms of squamipila as forming a monop hyletic assemblage. Based on the combined evidence (sequence divergenc e and phylogenetic position) it is concluded that squamipila, hypogram ma and natalis each represent separate species in the genus Ninox. The se findings have implications for conservation efforts in the region.