ornithology vs zoology

ornithology and zoology both are nouns.

Word	Noun	Adjective	Verb	Adverb
ornithology	Yes	No	No	No
zoology	Yes	No	No	No

As nouns, zoology is a hypernym of ornithology; that is, zoology is a word with a broader meaning than ornithology:

Other hypernyms of ornithology include zoological science.

ornithology (noun)	zoology (noun)
the branch of zoology that studies birds	the branch of biology that studies animals
	all the animal life in a particular region or period