Sexual Maturity: Age at first reproduction not yet measured at any Western site. Following data based on Mountain gorillas and gorillas in managed care.
Estrus cycle: estrus period = 1-2 days, 22-38 day cycle.
First pregnancy: 8.5-10 years
Gestation: 251-295 days
Young per birth: 1, twins rare
Reproductive Rate: 3.5 - 4.5 year birth interval
Infant mortality: varies depending on group 8%-43%
Western Lowland Gorilla and infant.
Image credit: © San Diego Zoo Global. All rights reserved.
Maple & Hoff, (1982)