Assertion: porcupine's diet | /r/CapableOf | vary by season
Facets:
value: as an herbivore
type: MANNER
Source sentences:
text: Their exact diet varies by season and location, but North American porcupines mostly eat leaves, twigs, bark, acorns, buds and flowers.
text: As an herbivore, the porcupine’s diet varies by season, according to the availability of plant foods.