Podiceps ruficollis vs grebe

Podiceps ruficollis and grebe both are nouns.

Word	Noun	Adjective	Verb	Adverb
Podiceps ruficollis	Yes	No	No	No
grebe	Yes	No	No	No

As nouns, grebe is a hypernym of Podiceps ruficollis; that is, grebe is a word with a broader meaning than Podiceps ruficollis:

Podiceps ruficollis: small European grebe
grebe: small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet

Podiceps ruficollis (noun)	grebe (noun)
small European grebe	small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet