slate-colored junco vs snowbird

slate-colored junco and snowbird both are nouns.

Word	Noun	Adjective	Verb	Adverb
slate-colored junco	Yes	No	No	No
snowbird	Yes	No	No	No

As nouns, snowbird is a hypernym of slate-colored junco; that is, snowbird is a word with a broader meaning than slate-colored junco:

slate-colored junco: common North American junco having grey plumage and eyes with dark brown irises
snowbird: small North American finch seen chiefly in winter

Other hypernyms of slate-colored junco include junco.

slate-colored junco (noun)	snowbird (noun)
common North American junco having grey plumage and eyes with dark brown irises	white Arctic bunting
	small North American finch seen chiefly in winter
	medium-sized Eurasian thrush seen chiefly in winter