secretary bird vs bird of prey

secretary bird and bird of prey both are nouns.

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

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

secretary bird: large long-legged African bird of prey that feeds on reptiles
bird of prey: any of numerous carnivorous birds that hunt and kill other animals

Other hypernyms of secretary bird include raptor, raptorial bird.

secretary bird (noun)	bird of prey (noun)
large long-legged African bird of prey that feeds on reptiles	any of numerous carnivorous birds that hunt and kill other animals