Vocalization
S. ulula has a variety of calls used by the different sexes in different situations. When attracting a mate the male usually lets out a rolled whistle of ulululululululul and a sound similar to tu-wita-wit, tiwita-tu-wita, wita, when perching at a potential nest site. The female’s call is usually less constant and more shrill.
When alerting to danger, the Northern Hawk-Owl lets out a sound similar to rike, rike, rike, rike. It also releases a high pitched scream followed by a yip when an intruder is near to the nest. To warn of impending dangers to a fledgling, the Hawk-Owl will let out a noise similar to ki ki kikikikiki. Calls can vary in length from 15 s to 2 min.
Read more about this topic: Northern Hawk-Owl