biologist vs naturalist

biologist and naturalist both are nouns.

Word	Noun	Adjective	Verb	Adverb
biologist	Yes	No	No	No
naturalist	Yes	No	No	No

As nouns, naturalist is a hyponym of biologist; that is, naturalist is a word with a more specific, narrower meaning than biologist:

biologist: (biology) a scientist who studies living organisms
naturalist: a biologist knowledgeable about natural history (especially botany and zoology)

biologist (noun)	naturalist (noun)
(biology) a scientist who studies living organisms	a biologist knowledgeable about natural history (especially botany and zoology)
	an advocate of the doctrine that the world can be understood in scientific terms