Assertion: bison's lifespan | /r/HasProperty | 12 to 20 years
Facets:
value: according to national geographic
type: OTHER
Source sentences:
text: America Bison achieve sexual maturity at between the ages of 2 and 4 years old, and its average lifespan in the wild is 12 to 20 years, according to National Geographic.
text: The average lifespan of bison is between 12 and 20 years.