ivorybill vs woodpecker

ivorybill and woodpecker both are nouns.

Word	Noun	Adjective	Verb	Adverb
ivorybill	Yes	No	No	No
woodpecker	Yes	No	No	No

As nouns, woodpecker is a hypernym of ivorybill; that is, woodpecker is a word with a broader meaning than ivorybill:

ivorybill: large black-and-white woodpecker of southern United States and Cuba having an ivory bill; nearly extinct
woodpecker: bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects

Other hypernyms of ivorybill include pecker, peckerwood.

ivorybill (noun)	woodpecker (noun)
large black-and-white woodpecker of southern United States and Cuba having an ivory bill; nearly extinct	bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects