At birth, pups weigh about four kilograms. During the first few weeks of life, they are weak and many do not survive. Pups are born with a black fur coat. In February, they moult into a silver-grey coat.

Only the cow looks after her pup. Bulls do not assist in pup rearing.

When the cow is at sea feeding, the pup remains at the colony. As it gets older, it spends a lot of time playing with other pups and practising swimming. It is completely dependant on its’ mothers milk until it is at least 8 months old. Then it starts to chase and catch fish. Around October each year, cows must get ready for the birth of their next pup. The 10 - 11 month olds, now called yearlings, are left to fend for themselves and must catch all the food they need.