FIGURE 14. Relationship between mass of predator and mass of largest recorded prey in several North American species of owls. Range of body mass includes smallest mean male and largest mean female weights for one or more subspecies of each species presented by Earhart and Johnson (1970). Prey records are from Earhart and Johnson (1970), Marti (1974), and Forsman et al. (1984). FPO, ferruginous pygmy owl; NPO, northern pygmy owl; SWO, saw-whet owl; BoO, boreal owl; BuO, burrowing owl; LEO, long-eared owl; SEO, short-eared owl; CBO, common barn owl; SpO, spotted owl; BdO, barred owl; GHO, great horned owl. Approximate body mass of largest species (woodrat, Neotoma) in the House Mountain microvertebrate assemblage is 154-177 g; a body mass of ca. 100-400 g is predicted for the Verde fossil owl (dashed oval). Note logarithmic scales.