The study of three western European owl communities revealed the existence of geographical patterns concerning food-niche characteristics of the individual owl species and, consequently, of community composition and structure. Middle and Northern European communities show a close packing of species along the food dimension of the niche; the ways in which the available food resources are exploited are very restricted owing to the abundance of a particular prey type (voles, Microtinae). With increasing scarcity of this microtine prey, some species are eliminated in the Mediterranean community, food exploitation methods are diversified, and some substantial dietary shifts occur.