bird of night vs bird of prey

bird of night and bird of prey both are nouns.

Word	Noun	Adjective	Verb	Adverb
bird of night	Yes	No	No	No
bird of prey	Yes	No	No	No

As nouns, bird of prey is a hypernym of bird of night; that is, bird of prey is a word with a broader meaning than bird of night:

bird of night: nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes
bird of prey: any of numerous carnivorous birds that hunt and kill other animals

Other hypernyms of bird of night include raptor, raptorial bird.

bird of night (noun)	bird of prey (noun)
nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes	any of numerous carnivorous birds that hunt and kill other animals