All the females in the group reproduce at around the same time.

Females reproduce no more than once every two years, perhaps longer.

Females reproduce every 2-3 years, usually to a single calf.

Neither males nor females will reproduce until they are at least two years of age.

This means that before 18 000 years ago, many females would be reproducing with the same few males.

Females that do no longer reproduce contribute to the survival of the young.

The females reproduce by parthenogenesis and seem content to live on their own.

When females reproduce, they have a single birth of one individual, and the gestation period lasts five months.

Females reproduce every 12-18 months and have a six-month gestation.

However, some adult females can reproduce without male input.