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
Southern boobook sites. Caves or ledges are alternative roosting sites if no suitable trees are available. Although unobtrusive, it may give itself away by droppings or pellets on the ground beneath. The southern boobook is mobbed by passerines if discovered. It may allow people to approach to within . The maximum age recorded from banding has been 15 years 11 months, in a bird caught and later caught again on Black Mountain in the Australian Capital Territory. Across Australia, breeding takes place from July to February, though peaks in October, and is generally earlier in more northern areas. Eggs are laid from