migrator vs fauna

migrator and fauna both are nouns.

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

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

migrator: an animal (especially birds and fish) that travels between different habitats at particular times of the year
fauna: a living organism characterized by voluntary movement

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

migrator (noun)	fauna (noun)
an animal (especially birds and fish) that travels between different habitats at particular times of the year	a living organism characterized by voluntary movement
traveler who moves from one region or country to another	all the animal life in a particular region or period