Figure 2
From: The role of menopause and reproductive senescence in a long-lived social mammal
Changes in the age-structure of female killer whales, from two populations since 1976. Dashed lines are included for clarity to demarcate individuals aged 15, 30, and 40 years. After the 2007 survey, there are 49 females in the southern population (9 older than 45). Not all northern residents are seen each year, so there is some uncertainty in the exact age distribution – if all animals are alive, it is estimated that there are 139 females in the northern population (13 older than 45).