There are accounts of Great Horned Owls attacking snakes and coming off second best. Nestlings are sometimes taken by Red-tailed Hawks, and other predators. Deaths from severe weather and starvation also occur. Although various infectious diseases and parasites have been found in the Great Horned Owl, no one really knows how many die of them. Adult Great Horned Owls face the possibility of death due to various human activities.
Some owls fly into power lines or are struck on highways.
Others are shot by irate farmers or thoughtless hunters. Fortunately, laws that protect Great Horned Owls from needless persecution have been passed in each province. Owls that die of natural causes can reach a great age. The Great Horned Owl remains so widely distributed and remarkably tolerant of major habitat disturbance by people that its future seems secure. Its ability to exploit a great diversity of prey and its largely nocturnal activity are undoubted advantages.