Seals
Cape Fur Seals: (Arctocephalus pusillus pusillus)
IUCN classification: Least Concern
- Cape fur seals are “endemic” to Namibia and South Africa.
- Adjacent to Dyer Island is Geyser Rock, a Cape fur seal colony that is 55,000 seals strong! Every year, 10,000-12,000 pups will be reared but only 1/XX will survive to adulthood.
- Cape fur seals are mammals, like us, which means they give live birth and feed their young with milk.
- Cape fur seals have been recorded at 600m depth!
- Cape fur seals mostly eat boney fish, but do also eat squid, octopus, and, on occasion, birds like the African penguin.
- Females can weigh up to 120kg and males up to 360kg! This is because male seals must fight off competing males during mating season.
- Mating and breeding time is November/December of every year. This is when male seals set up “harems” or territories of females to mate with. Females mate immediately after giving birth.
- Cape fur seals are the main prey for great white sharks.
- Cape fur seals are the main prey for great white sharks.
Why would a seal eat a penguin?
- More research needs to be done in order to understand the complex ecosystem surrounding Dyer Island. This is why DICT research, Michelle Wcisel[LINK RESEARCHER PAGE], is basing her M.Sc. thesis on this very topic.
- It is thought that small groups of “rogue” seals, typically young males, specialize in predating on seabirds. They do not consume the whole bird, but rather target the stomach cavity of returning birds. Returning birds are typically full of fish from foraging, so the seals are really after the fish meal inside destroying the bird in the process.
- There is an especially delicate system at Dyer Island where penguin and seal colonies neighbor each other. Therefore, understanding the complexities of this system are imperative to the survival of the penguins.
