Christmas boobook lores and throat, yellow eyes, legs and feet. It is approximately 26–29 cm in length and 130-190 grams in weight with the female slightly larger than the male. The double-noted hoot, "boo-book," has a clucking quality with the second note usually lower in pitch. The begging call of juveniles is a high-pitched trill. Vocalisations are similar to those described for the Southern Boobook "N. novaeseelandiae" and include individual variation in advertisement calls. This may be useful in estimating owl densities as radio-tracking can be impractical in some terrains. A recording, courtesy of Richard Hill and Owl Pages http://www.owlpages.com/sounds/Ninox-natalis-2.mp3 Its natural
Morepork single species. Examining both morphological and genetic (cytochrome "b") characters, Michael Wink and colleagues concluded that the southern boobook was distinct from the morepork, as was the Tasmanian boobook, which should be raised to species status as "Ninox leucopsis". Four subspecies of "Ninox novaeseelandiae" are recognised by the IOC, two of which are extinct: The morepork is long, with female slightly larger than the male. She is slightly heavier, too, at 170-216 g compared with the male's 140-156 g. The morepork has generally dark brown head and upperparts, with pale brown spots on head and neck and white markings on