The brown fur seal feeds on pelagic schooling fish, such as pilchards, anchovies and hake, as well as cephalopods such as squid and octopuses, and also crustaceans. The brown fur seal has been known to dive to depths of up to 500 metres while foraging (2). Great white sharks (Carcharodon carcharias) and orcas (Orcinus orca) are known to prey on fur seals foraging out at sea, while the black-backed jackal (Canis mesomelas) and brown hyaena (Hyaena brunnea) also take pups while they are on land (1).
The male brown fur seal defends a territory with good resources to attract females (7). This species exhibits a ‘harem’ system in which one male mates with many females (8). Most seal and sea lion species mate on land; however, as brown fur seal females begin leaving on foraging trips before becoming receptive, some males follow the females out to sea, where they mate in the water (7).
The female brown fur seal becomes sexually mature at around the age of 3 years, but the male may not reach maturity until around 9 to 12 years. Breeding occurs from October the January, with births usually peaking in the first week of December. The female brown fur seal gives birth to a single pup after a gestation period of around one year (1). The brown fur seal pup measures about 60 to 80 centimetres at birth (2).
After giving birth, the female brown fur seal divides her time between attending the pup and foraging out at sea. The pup stays at the colony during this foraging time and survives off the milk it received during the female’s last visit. The female brown fur seal mates again just six days after giving birth, but continues to suckle her pup for up to 12 months (9). The male brown fur seal is known to live to at least 19 years of age, with females living to about 21 years (5).