fulmar petrel vs petrel

fulmar petrel and petrel both are nouns.

Word	Noun	Adjective	Verb	Adverb
fulmar petrel	Yes	No	No	No
petrel	Yes	No	No	No

As nouns, petrel is a hypernym of fulmar petrel; that is, petrel is a word with a broader meaning than fulmar petrel:

fulmar petrel: heavy short-tailed oceanic bird of polar regions
petrel: relatively small long-winged tube-nosed bird that flies far from land

fulmar petrel (noun)	petrel (noun)
heavy short-tailed oceanic bird of polar regions	relatively small long-winged tube-nosed bird that flies far from land