A boat trip to Duiker Island

The trip out to the island was relatively smooth. The sea was still calm following yesterday’s good weather. We sat inside until we reached the island, where we ventured out on deck to photograph the seals. It is illegal to step on to the island which is a Cape Fur Seal and bird sanctuary. As well as the seals, the island is home to Cape Cormorant, Black Back Gulls, Bank Cormorant, Kelp Gulls, and Hartlaub Gulls.

The vast majority of the Cape Fur Seals found on Duiker Island are males waiting out their time until they reach breeding age, which happens between 8 and 12 years, depending on their size. The island is not a breeding colony as the sea can get very rough and the pups would get swept away and drown.

Duiker Island is most densely populated between January and March which is moulting season. During this time, they remain on land. They don’t go to sea in search of food. Instead, they rely on fat stored in their blubber.

Cape Fur Seals breed in November and December in breeding colonies around the coastline of South Africa and Namibia. The gestation period is 12 months, so pups are also born in the last two months of the year. A female seal (cow) reaches breeding age at four or five years old. She usually only gives birth to one pup at a time. She recognises her pup by its smell and its call, and will only mother her own offspring. Seal pups are entirely dependent on their mother’s milk for the first six to ten months of their lives.

Seals grow quickly. They start to swim at six weeks old. By seven to ten months, they can spend two or three days at sea alone and can already swim long distances. Tagged Cape Fur Seals have swum from Cape Town to Cape Cross in Namibia, a distance of 1600 kilometres, at the age of just eight months.

Cape Fur Seals can dive to a depth of 36 metres or more. They cannot breathe underwater and close their ears and nostrils tightly when they dive. Even when they are sleeping in the water, they have to surface to breathe – every 10 to 15 minutes for pups, and every half an hour for adults.

Some more facts about Cape Fur Seals:

• They eat fish, shrimps, shellfish, and squid.
• They can hear quite well on land, but their hearing underwater is much better. They are very good at knowing what direction a sound is coming from.
• Their eyes are adapted to see both on land and in the water.
• They maintain a constant body temperature of 38.5˚C.
• Bulls can weigh up to 350 kilograms, and cows up to 113 kg.

When we got back to the harbour, a bizarre calypso group was playing and dancing for us. We gave them a tip as we got off the boat. On the quayside, a local was feeding a large bull seal by hand and encouraging tourists to stroke it and sit on its back to have photos taken! It’s 2023 for goodness sake!! Stop it!!Read more