The breeding call is a tremulous braying call, the equivalent of the bleating call of the Powerful Owl. Some Boobooks have been known to hunt mainly mice or small ground birds. Flying insects are taken by hawking flight through and above trees, taking only one insect each flight, and transferring it to the beak before bringing it to the nest or landing to eat it. Other insects are snatched from foliage or caught on the ground. Boobooks often hunt around street lights and along roads where many are hit by cars.
Pairs perch close together with the male giving 'pot pot por' call for long periods.
This may commence well before start of season. The nest can be a wide variety of tree hollows - the tree may be alive or dead with a hole in a limb or the main trunk, upright or sloping. The male cleans out the hollow before eggs are laid - usually 2 or 3, rarely up to 5. They are laid at 1 to 2 day intervals and are incubated for 35 days. The young have white down and are fledged in 5 to 6 weeks.