In a two year study, Christmas Island Hawk-Owls Ninox natalis chose to
roost in the bottom third of the canopy of trees with particularly de
ep crowns, in areas with fewer low understorey and more mid-level unde
rstorey trees, suggesting a preference for sheltered, concealed, roost
sites with easy escape routes below them. Analysis of regurgitated pe
llets, stomach samples and faeces showed the owls to be primarily inse
ctivorous, eating a wide variety of medium to large insects, especiall
y Orthoptera, Lepidoptera and Coleoptera. They supplemented this diet
with vertebrates of which introduced Black Rats Rattus rattus were the
most important in this study. Other studies have found native and int
roduced geckos as well as the Christmas Island White-eye Zosterops nat
alis in their diet. Owls snatched their prey from the understorey, haw
ked insects around streetlights, 'long-stay perch hunted' along roadsi
des and presumably also fed in and above the canopy.