Even more so than diurnal raptors, a wide diversity of owls are known to fall prey to Cooper's hawks. Despite the temporal differences of their activity, the intensive hunting methods of Cooper's hawks may allow them to access roosting owls more readily than other types of hawks. Small owls that the Cooper's hawk have been known to prey upon have included flammulated owls ("Psiloscops flammeolus"), eastern screech-owls ("Megascops asio"), western screech-owls ("Megascops kennicottii"), whiskered screech-owl ("Megascops trichopsis"), elf owl ("Micrathene whitneyi"), northern pygmy owl ("Glaucidium gnoma"), ferruginous pygmy owl ("Glaucidium brasilianum"), burrowing owl ("Athene cunicularia"), boreal owl ("Aegolius funereus") and northern saw-whet owl ("Aegolius acadicus"). Medium to large-sized owls are sometimes also prey for Cooper's hawks have been known to include long-eared owl ("Asio otus") and perhaps the rather large spotted owl ("Strix occidentalis"). Most impressively, an instance was observed where a Cooper's hawk appeared to have preyed upon an adult of the rather larger (averaging about ) barred owl ("Strix varia"). There is also a record of a barred owl preying on a Cooper's hawk as well.