They start to appear in the waters of the southern cape in June and increase in numbers to reach peak numbers in August, September, October and November. Watchers from the shores of Walker Bay in winter and early spring often see a group of whales engaged in boisterous mating, with up to 6 males competing for the attention of a single female.

The whale gestation period is about 12 months and the calf is born tail first and near the surface. The newborn instinctively swims to the surface within 10 seconds for its first breath. Its mother, using her flippers helps it. Within 30 minutes of its birth the baby whale can swim. The newborn calf is about 4.5-7 m long. The baby is nurtured with its mother's milk and is weaned after about 1 year. The mother nurses the calf by rolling on her side and ejecting her milk into its mouth with muscles deep inside her breasts. They feed on approximately 600 litres of milk per day! Calving is thought to occur only every three to five years. Right whales only long-term bonds are between mother and calf. The Overberg coast is one of the world's most important nursery areas for the southern right whale.