Southern boobook pale spots. It has grey-green or yellow-green eyes. It is generally nocturnal, though is sometimes active at dawn and dusk, retiring to roost in secluded spots in the foliage of trees. The southern boobook feeds on insects and small vertebrates, hunting by pouncing on them from tree perches. Breeding takes place from late winter to early summer, using tree hollows as nesting sites. The International Union for Conservation of Nature has assessed the southern boobook as being of least concern on account of its large range and apparently stable population. English ornithologist John Latham described the boobook owl as "Strix
Failure to refer Failure to refer Failure to refer, also reference failure or failure of reference, is the concept that names can fail to name a real object. According to Bertrand Russell's theory of truth, there is only one actual world, and a statement's truth value depends on whether the statement obtains in the actual world. Continuing the tradition of Gottlob Frege, Bertrand Russell posited that a name picks out, or refers to, a real object in the world (Russell's correspondence theory of truth). The name "Genghis Khan" thus picks out the 12th and 13th century Mongol leader we know by that name.