Commerson's from South America and Kerguelen areas differ in their ages and lengths of sexual maturity.
- A female from the South America population is sexually mature and can bear a calf when she is 5 to 8 years old and about 130 cm (51 in.). Males are mature at about 5 to 6 years old and 127 to 131 cm (50-51.6 in.).
- A female from the Kerguelen population is sexually mature when she is about 5 years old and 165 cm (65 in.). Males are mature at about 8 years old.
Gestation is about 12 months.