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Aerodynamic parameters, such as wing loading, are important indicators of flight maneuverability. We studied two subspecies of the American Barn owl (<i>Tyto furcata</i>), the North American subspecies, <i>T.f.pratincola</i>, and the Galapagos subspecies, <i>T.f.punctatissima</i>, with respect to aerodynamic parameters and compared our findings with those in other owl and bird species. The body mass of <i>T.f.pratincola</i> is about two times higher than that of <i>T.f.punctatissima</i>. Wing loading between the two subspecies scales allometrically. Wing loading in <i>T.f.pratincola</i> is about 50% higher than in <i>T.f.punctatissima</i>. The scaling of wing length is not statistically different from the prediction for isometric scaling. By contrast, the wing chord in <i>T.f.punctatissima</i> is larger than predicted by isometric scaling, as is the wing area. The scaling of wing loading observed here for <i>T.f.punctatissima</i> differs considerably from the scaling in other owl and bird species as available in the literature. We speculate that the allometric scaling helps <i>T.f.punctatissima</i> to catch smaller prey such, as insects that are found in many pellets of <i>T.f.punctatissima</i>, despite the fact that in both subspecies, small rodents make up most of the diet.