Sex-specific diet analysis of the Eurasian Eagle Owl in Finland

Abstract

In this study we used the stomach contents of Eagle Owls (primarily 1st winter birds) made available from Finnish museums or taxidermists. Female owls from Finland had an average weight of 2760g (N=50), while male weights averaged 2200g (N=35). The most common prey for both male and female owls was Field Vole. Despite our limited material (42 female and 24 male stomachs), it suggests that Eagle Owl females preyed upon relatively larger prey (Hedgehogs, Muskrat and a wider variety of larger birds) than males. A more correct way to test whether females and males select different prey, diet for males and females hunting in the same area simultaneously should be studied. This would include intensive radio telemetry and/or the video filming of the sexed individuals.The dead found Eagle Owl specimens used in the current study, however, provide the cheapest avenue to address sexual dietary differences in species where internal examination is the only sure way to determine gender.