little owl vs hooter

little owl and hooter both are nouns.

Word	Noun	Adjective	Verb	Adverb
little owl	Yes	No	No	No
hooter	Yes	No	No	No

As nouns, hooter is a hypernym of little owl; that is, hooter is a word with a broader meaning than little owl:

little owl: small European owl
hooter: nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes

Other hypernyms of little owl include bird of Minerva, bird of night, owl.

little owl (noun)	hooter (noun)
small European owl	nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes
	a device on an automobile for making a warning noise
	informal terms for the nose