The Boreal Owl remained for four days, during which it moved its daytime roost from the bones to a nearby shed. It spent the next three daytimes perched on a propane cylinder, but was gone each evening after dark. A Leach's Storm-petrel colony was handy, and the owl may have been feeding on them – one morning the owl was standing with a dead petrel in its claws. Petrels coming into the colony at night were perhaps easy prey for the nocturnal predator. Boreal Owls also turned up on April 29 2000, in late November 2001, and on October 16 2004.