Stolz, Gary M. 2008
The great horned owl is common throughout North America. It is a powerful predator with strong talons and sharp beak. It eats mammals, birds and reptiles when available. In the far north it eats snowshoe hare, geese, mice, voles and lemmings. Further south it might also eat snakes, lizards, squirrels and skunks. Like most Owls it is nocturnal relying on its keen vision and silent flight to suprise its prey.
It’s “horns” are actually tufts of feather above its ears that look like horns.
Cornell Lab of Ornithology
Vanner, Michael. The Complete Encyclopedia of North American Birds. Parragon Publishing; Bath, UK, 2005.