Fulmar petrel and Petrel

Fulmar petrel noun - Heavy short-tailed oceanic bird of polar regions.

Petrel and fulmar petrel are semantically related. In some cases you can use "Petrel" instead a noun phrase "Fulmar petrel".

Petrel noun - Relatively small long-winged tube-nosed bird that flies far from land.

Fulmar petrel and petrel are semantically related. Sometimes you can replace phrase "Fulmar petrel" with "Petrel", this terms are similar.