hawk owl vs bird of Minerva

hawk owl and bird of Minerva both are nouns.

Word	Noun	Adjective	Verb	Adverb
hawk owl	Yes	No	No	No
bird of Minerva	Yes	No	No	No

As nouns, bird of Minerva is a hypernym of hawk owl; that is, bird of Minerva is a word with a broader meaning than hawk owl:

hawk owl: grey-and-white diurnal hawk-like owl of northern parts of the Northern Hemisphere
bird of Minerva: nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes

Other hypernyms of hawk owl include bird of night, hooter, owl.

hawk owl (noun)	bird of Minerva (noun)
grey-and-white diurnal hawk-like owl of northern parts of the Northern Hemisphere	nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes