Podilymbus podiceps vs grebe

Podilymbus podiceps and grebe both are nouns.

Word	Noun	Adjective	Verb	Adverb
Podilymbus podiceps	Yes	No	No	No
grebe	Yes	No	No	No

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

Podilymbus podiceps: American grebe having a black-banded whitish bill
grebe: small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet

Podilymbus podiceps (noun)	grebe (noun)
American grebe having a black-banded whitish bill	small compact-bodied almost completely aquatic bird that builds floating nests; similar to loons but smaller and with lobate rather than webbed feet