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 the nest with food. A purring or braying call is used by both sexes as a contact call around the nest and (more quietly) when bringing food to nestlings, or by the female to beg for food from the male. The female makes a low trill during courtship and nesting. Growls, high-pitched yelps, and screeches can be made when attacking intruders. The southern boobook maintains and defends a territory in breeding season; whether this continues for the rest of the year is unclear. It retires to densely foliated spots in trees in the daytime, each individual often having several roosting