slate-colored junco vs junco

slate-colored junco and junco both are nouns.

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

As nouns, junco is a hypernym of slate-colored junco; that is, junco 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
junco: small North American finch seen chiefly in winter

Other hypernyms of slate-colored junco include snowbird.

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