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
Failure to refer Any sentence in which we attach a predicate to the name "Genghis Khan" is true if the predicate obtained in the actual world. Any sentence in which the predicate does not obtain for Genghis Khan is false. The Wikipedia statement “"Genghis Khan founded the largest contiguous empire in world history"” is thus true, and the statement “"Genghis Khan was one of the most successful playwrights of late Victorian London"” is false. As an example for a name that fails to refer to a real object, Russell used “"the present king of France"“ in a 1905 article. According to the Russellian