Assertion: gorilla's group | /r/HasProperty | one dominant silverback
Facets:
value: for several years
type: TEMPORAL
Source sentences:
text: A typical group contains: one dominant silverback, who is the group's undisputed leader; another subordinate silverback (usually a younger brother, half-brother, or even an adult son of the dominant silverback); one or two blackbacks, who act as sentries; three to four sexually mature females, who are ordinarily bonded to the dominant silverback for life; and from three to six juveniles and infants.
text: The group of gorillas is dominated by a male or a silverback for several years.