Widespread in North American forest regions including the Rocky Mountains, the Boreal Owl (Aegolius funereus) was once the most numerous predatory bird in Eurasian boreal forests. Synthesising the results of unique long-term studies of Boreal Owls, this book explores hunting modes, habitats and foods, prey interactions, mating and parental care, reproduction, dispersal, survival and mortality, population regulation and conservation in boreal forests. Providing a detailed introduction to the species, the authors study the complex interactions of Boreal Owls with their prey species. They examine the inter-sexual tug-of-war over parental care, and the behavioural and demographic adaptations to environmental conditions that predictably and markedly fluctuate both seasonally and multi-annually. They also question whether Boreal Owls are able to time their reproductive effort to maximise lifetime reproductive success. Discussing the effect of modern forestry practices on owl populations, the book also examines how Boreal Owls could be managed to sustain viable populations.