The dense coat is made of woolly underfur and long, coarse outer hairs. This traps air which waterproofs and insulates the seal. Like all seals, they moult each year, replacing their old fur with new growth. A layer of fat assists with warmth and streamlining. Of the nineteen fish species known to be consumed, Jack Mackerel, Redbait and Leatherjackets form the main prey items.
Females give birth to a single pup which is fed on thick, rich milk.
Once a cow gives birth for the first time, she is practically in a continuous state of lactation for the rest of her life, with maybe only a few weeks off between weaning last season's pup and having another. Australian fur seals breed on five rocky Bass Strait islands, but because seals only come ashore to rest and breed, it is impossible to know exactly how many there are. Based on counts at the breeding colonies each year, scientists estimate there are about 5000 pups born in Tasmanian waters each year. However, not all pups will survive to become adults. This natural mortality continues throughout the life of the seal, but at a lower level than that of the pups.