The Breeding Biology and Diet of the Masked Owl Tyto novaehollandiae Near Eden, New South Wales

Abstract

Summary: In forested environments, the Masked Owl Tyto novaehollandiae is a highly cryptic species whose presence is easily overlooked, except for short periods early in the breeding season when it becomes more vocal and its presence is readily detected. The results of three successful breeding attempts are reported in which laying occurred between late March and mid-July. Two young were fledged on one occasion and at least one young was fledged on two other occasions. Masked Owls in one territory bred successfully in the same nest hollow during 1990 and 1994. The owls either did not nest during the three intervening years or they did so in an unlocated tree. The habitat for the owls was dry open-forest in rugged terrain interspersed with narrow bands (c. 100 m wide) of tall, wet riparian forest. One nest tree was located in one of these riparian zones and was surrounded by a large area of mainly unlogged forest, although there were several recently logged areas nearby. The diet of these owls consisted almost entirely of small native ground-dwelling or scansorial mammals, none of which is dependent on continuous areas of old-growth forest. At least two of the main prey species are characteristically abundant in riparian forest with a dense understorey or ground layer. In contrast to other studies, no introduced species were recorded in the diet. The apparent rarity of the Masked Owl is difficult to explain given its dietary flexibility and ability to use disturbed habitats.