All of the Southern Ocean’s South Georgia Island is spectacular, but Gold Harbor, near the southeastern end of the 106-mile long sub-Antarctic Island is a stunner. With the hanging icefall of Bertrab Glacier looming over the long arc of the gravel-shored bay, Gold Harbor teems with wildlife. Southern Fur Seals, like those in the foreground here, some 25,000 pair of breeding King Penguins, a small colony of 300 or so pairs of Gentoo Penguins, even an endemic pipit species; as well as the star of the show. Those would be the largest member of the seal family, the largest carnivore that isn’t a cetacean and an animal so incredibly homely that they are pretty cute. They can fart continuously for a stopwatch-measured 45 seconds and likely belch even longer. They are Southern Elephant Seals, Mirounga leonine, and WC got to spend some quality time with them on South Georgia Island back in 2002.
(All of these photos but the first were taken with a 300mm supetelephoto lens. These guys can move surprisingly fast.) The elephant seals WC encountered at Gold Harbor were subadults, not yet big enough to compete for a harem. While males reach sexual maturity between 3-6 years of age, they do not begin breeding until about 10 years of age. The business of staking out and defending a territory and assembling a harem is strenuous; a beach master may go three months without a meal, guarding his ladies, driving off interlopers and mating. As big at these Gold Harbor fellows are, the full adults males are even bigger.
This animal can routinely dive day and night to average depths of 300-600 meters for 20-22 minutes. Their deepest dives are made during daylight hours, when they have been documented to dive as deep as 2,000 meters for as long as 2 hours. As much as 90% of their time is spent beneath the surface, coming up to breathe for 2-3 minutes between dives. Homely as they may be hauled out on the shores of Gold Harbor, they are elegant in the water.
Southern Elephant Seals exhibit the greatest sexual dimorphism of any mammal, at least in terms of mass ratio, with males typically five to six times heavier than females. On average female southern elephant seals weigh 400 to 900 kilograms (880 to 1,980 lb) and measure 2.6 to 3 meters (8.5 to 9.8 ft) long, whereas bulls can range from 2,200 to 4,000 kilograms (4,900 to 8,800 lb) and grow to 4.2 to 5.8 meters (14 to 19 ft) in length. For comparison, among the northern elephant seal and the sperm whale – two other large marine mammals that are highly sexual dimorphic by size – males typically outweigh females by a factor of three to four. These subadults are not yet fully grown, but are already huge.
The big marine mammals come ashore to breed and to molt, but otherwise spend their entire lives at sea, generally around the edge of Antarctica. When the whalers had hunted all of the whale species to economic extinction, they shifted their unrelenting hunting pressure to elephant seals. The species is still recovering, and now faces changes wrought by climate change in the Southern Ocean. It’s appalling that human activities have endangered species at both the far north and far south of this planet. There will be reckoning.