The Spotted Owl is similar to the Barred Owl but has cross-shaped markings on the underparts where the Barred Owl is alternately barred on the breast and streaked on the belly. Barred Owls are grayer than Spotted Owls. Great Gray Owl is much larger with yellow eyes. Great Horned and Long-eared Owls have ear tufts.
Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.