Assertion: emperor penguin | /r/Desires | vocal calls
Facets:
value: alone
type: MANNER
value: for identification
type: PURPOSE
Source sentences:
text: As the species has no fixed nest sites that individuals can use to locate their own partner or chick, emperor penguins must rely on vocal calls alone for identification.
text: Since they have no permanent nest sites, emperor penguins depend on vocal calls to identify their partner or chick.