Morepork they conceded the two were easily distinguishable in appearance, so maintained the three as subspecies; the Tasmanian boobook only diverged by 2.7% from the other two, while the powerful and rufous owls diverged by 4.4% from each other. Leading from this, the southern boobook was split from the Tasmanian boobook and morepork in volume 5 of the "", however several authors, including Les Christidis and Walter Boles, contested that the data had been misinterpreted from the Norman study, which had not sampled any Australian mainland boobooks at all. They treated the three taxa (southern, Tasmanian boobooks, and moreporks) as a
Australasian darter but covered in a layer of chalky lime, and become progressively scratched and stained over the incubation period. Australasian darter The Australasian darter or Australian darter ("Anhinga novaehollandiae") is a species of bird in the darter family, Anhingidae. It is found in Australia, Indonesia, and Papua New Guinea. It weighs around 2.6 kg and spans 86–94 cm (34–37 in) in length. John Gould described the Australasian darter as "Plotus novaehollandiae" in 1847. Closely related to American ("Anhinga anhinga"), African ("Anhinga rufa"), and Oriental ("Anhinga melanogaster") darters, the Australasian darter has been classed as a subspecies of the African or African