scavenger vs fauna

scavenger and fauna both are nouns.

Word	Noun	Adjective	Verb	Adverb
scavenger	Yes	No	No	No
fauna	Yes	No	No	No

As nouns, fauna is a hypernym of scavenger; that is, fauna is a word with a broader meaning than scavenger:

scavenger: any animal that feeds on refuse and other decaying organic matter
fauna: a living organism characterized by voluntary movement

Other hypernyms of scavenger include animal, animate being, beast, brute, creature.

scavenger (noun)	fauna (noun)
any animal that feeds on refuse and other decaying organic matter	a living organism characterized by voluntary movement
someone who collects things that have been discarded by others	all the animal life in a particular region or period
a chemical agent that is added to a chemical mixture to counteract the effects of impurities