Yellowstone is home to a healthy population of Great Horned owls (Bubo virginianus). Distinctive tuffs over their ears give them their name. Their call is a low-pitched but loud ho-ho-hoo hoo hoo; sometimes it is only four syllables instead of five. The female's call is higher and rises in pitch at the end of the call. Young owls make hissing or screeching sounds that are often confused with the calls of Barn Owls. Pebble Creek, Yellowstone.