On our journey to the Skeleton Coast Park we stopped off at Cape Cross, 115km north of Swakopmund, to see a breeding colony of between 80 000 and 100 000 Cape fur seals (Arctocephalus pusillus pusillus). And what an amazing sight it was, with seals as far as the eye could see. The Namibian Wildlife authorities have set up a boardwalk so that you can walk above and between the seals without disturbing them. The area understandably smells dreadful, but it’s a small price to pay for such an amazing sight.
The fur seals (family Otariidae) are also known as ‘eared’ seals as they have external ears, which other true seals don’t have. There are three species of fur seals along the coast of Southern Africa.
These seals don’t migrate and are present at Cape Cross throughout the year. The males spend very little time at the colony during the non-breeding season – they’re busy building up blubber and food reserves that sustain them for about six weeks while they establish a territory and gather up a harem of between 5 and 25 females when its time to mate.
Shortly after the male arrives, the females come ashore to give birth to a single pup, weighing about 5 – 7 kgs. Within a week of the birth, the male mates with all the females in his harem and their fertilized ova remain dormant for about three months before the nine month gestation period begins. The pups are born within a six week period between November and December and start to suckle during the first hour of birth.
After the mothers and babies have bonded, the mothers leave the pups to forage at sea, often for days at a time. While the mothers are out gathering food, the pups congregate together. Fortunately mothers recognize their baby’s cries otherwise they could never be reunited.
The pups suckle for about a year, but start eating solids, like fish and crustaceans, when they’re four to five months old. They are born with thick black coats, which moult to an olive-grey colour after a few months.
The pups face a number of dangers as they are growing up and their mortality rate is estimated to be about 27% of the total born. Black-backed jackals (Canis mesomelas) and Brown hyaenas (Hyaena brunnea) are their main predators. They can also be crushed during a stampede, drowned or abandoned. Culling is also a contentious issue and we know that it does take place at Cape Cross. It is euphemistically termed as a “management programme” in their brochure.
The cold waters of the Atlantic Ocean provide rich pickings for the Cape fur seals, with pilchards, masbankers, squid, octopuses and other crustaceans being readily available for them to eat. They eat on average about 8% of their body weight per day, which is rather a lot considering that the males weigh in at between 180 kg and 360 kg and the females at approximately 75 kgs.
If you’ve had enough of seals and are driven away by the smell, you can go and have a look at a replica of the cross erected by Diego Cao, the first European to set foot on the Namibian coast in 1486. It is located adjacent to the seal colony and was placed in honour of John I of Portugal.