In North America, long-eared owls also primarily rely on small rodents in their diet, but their diet is somewhat more diverse by rodent family and less completely reliant on voles than their Eurasian counterparts. In general, the further north they are found in North America, the more restricted and vole based the diet is for this species. While diets are poorly researched in detail in Canada, in the northern tier states of Massachusetts, Michigan, Minnesota, Ohio, New York, Wisconsin and northern Oregon voles were easily the main prey for long-eared owls. In particular, the meadow vole ("Microtus pennsylvanicus") tends to be a dietary staple, such as in the two of the larger American studies, in Michigan where they constituted 70.6% of 3269 prey items and in Wisconsin where they constituted 83.4% of 3273 prey items. Another regularly featured vole in the diet in America is the prairie vole ("Microtus ochrogaster"), but few other voles seem to be taken other than opportunistically excluding Oregon where the gray-tailed vole ("Microtus canicaudus") and Townsend's vole ("Microtus townsendii") locally led the foods. In North America, non-arvicoline cricetid rodents such as the genus "Peromyscus", or deermice, and the smaller "Reithrodontomys", or harvest mice, fill the niche of small wild mice and may be irresistible to hunting long-eared owls. "Peromyscus" mice were the main foods for this species in Colorado, Illinois and most studies from Iowa (composing up to 59.1% of the local diet).