Ornate Owl Head by BioWorkZ
Red-Tail Skull by BioWorkZ on DeviantArt
Great Horned Owl by BioWorkZ Pinned by www.myowlbarn.com
Sibley's Owls of North America (available in poster format too), via Sibley Guides
Hawk Species at Hawk Mountain | Hawk Mountain Sanctuary: Raptor Conservation, Education, Observation & Research
birds of prey - Google Search
Owl types. Handy little poster for identifying Northern Hemisphere Owls.