Christmas boobook

The Christmas boobook (Ninox natalis), also known as the Christmas hawk owl, Christmas Island boobook or Christmas Island hawk owl, is a species of owl in the family Strigidae.

Closely related to the hawk-owls of genus Ninox, which occur in Southeast Asia and Australia, N. natalis was first classified at species level by J.J.Lister in 1888. It was not until 1998, however, that DNA testing confirmed its status as a separate species from other owls.

The Christmas Island hawk-owl is a small, rufous-brown hawk-owl with a barred breast, dark chestnut facial mask, whitish brow, 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.

Its 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 Australian boobook (Ninox boobook) and include individual variation in advertisement calls. This may be useful in estimating owl densities as radio-tracking can be impractical in some terrains.