What's the noun for owler? Here's the word you're looking for.
owl
Any of various birds of prey of the order Strigiformes that are primarily nocturnal and have forward-looking, binocular vision, limited eye movement, and good hearing. [from 8th c.]
(by extension) A person seen as having owl-like characteristics, especially appearing wise or serious, or being nocturnally active. [from 14th c.]