what size are owls
The Average Size of Owls. The average size of owls varies depending on the species. Bubo virginianus or the great horned owl has an average length of 18 to 27 inches. Generally considered as the smallest owl, Micrathene whitneyi or the elf owl only grows at an average length of 5 to 12 inches.Bubo bubo or the Eurasian eagle owl lives in Asia and Europe, which has an average length of 23 to 30 inches.eanwhile, the average length of Aegolius harrisii or the buff-fronted owl is 9.06 inches. Other notable owl species include Aegolius ridgwayi or the unspotted saw-whet owl that grows 7.09 inches long and Aegolius funereus or the boreal owl that grows at an average length of 8.66 to 10.63 inches.