migrator vs emigre

migrator and emigre both are nouns.

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

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

Other hyponyms of migrator include departer, goer, leaver, emigrant, emigree, outgoer, evacuee, immigrant, rusher, colonist, settler.

migrator (noun)	emigre (noun)
an animal (especially birds and fish) that travels between different habitats at particular times of the year	someone who leaves one country to settle in another
traveler who moves from one region or country to another