The Northern Spotted Owl (Strix occidentalis caurina), listed as a threatened subspecies in 1990, has been at the center of forest-management controversies in the Pacific Northwest for more than three decades. The political battles fought over the conservation of the owl and its habitat, and the effects of those battles on the regional economy, are a familiar story. Those battles are barely mentioned in “Population Demography of Northern Spotted Owls,” the new monograph in the Cooper Ornithological Society’s Studies in Avian Biology series. The authors instead present the results of their analyses of demographic data from throughout the range of the subspecies, information that is certain to figure heavily once again in the scientific and political debates.