Norfolk boobook morepork, being a small brown hawk owl with mottled plumage. It was smaller, darker and more reddish in colouring than the Australian subspecies, with much spotting. However, it was slightly larger than the nominate subspecies from New Zealand; female boobooks are larger than the males, with New Zealand females comparable in size to Norfolk Island males, a factor which gave rise to sexing difficulties with hybrid birds in the conservation management program. The owl inhabited the island's subtropical rainforest, which was largely cleared in the 19th century following human settlement. Most of the remaining forest lies within the small (4.65
Southern boobook treated Australian and New Zealand boobooks, along with several taxa from Indonesia and Papua New Guinea, as one species—"Ninox novaeseelandiae"—with 16 subspecies. In his 1968 book "Nightwatchmen of the Bush and Plain", Australian naturalist David Fleay observed that the boobooks from Tasmania more closely resembled those of New Zealand than those from mainland Australia, though he followed Mees in treating them as a single species. The southern boobook was split from the Tasmanian boobook and morepork in volume 5 of the "" in 1999, though several authors, including Australian ornithologists Les Christidis and Walter Boles, continued to treat the three