No better way to keep cool in the summertime than writing about animals that spend their lives in the Arctic.
The Bearded Seal (Erignathus barbatus) is a medium-sized seal (though they are the largest seal species in the Arctic) whose name refers both to its heavy jaw and its appearance of facial hair. It has many long face whiskers that curl downward when dry. They are found primarily in Arctic waters and waters adjacent to the Arctic Ocean, but fossil records indicate that their ancestors lived as far south as South Carolina during the Pleistocene epoch. The Inuit name for Bearded Seals is ugjuk (plural ugjuit).
Unlike some other pinnipeds, sexual dimorphism between adult males and adult females is not extremely pronounced. Bearded Seals grow up to 8.9 feet (2.7 meters) in body length, and top out at about 948 pounds (430 kg) in weight. They have squared-off front flippers and are one of the few seal species to have two pairs of teats. They have extremely tough skin, and they are one of the species hunted by Inuit less for food and more as a staple building material. Their skin can be used to fashion whips, tents, the skin of a wood-framed boat, shoes and dog sled harnesses. Polar bears also prey on Bearded Seals.
When in the water, Bearded Seals stick close to the ocean floor, feeding on fish, shrimp, crabs, clams and squid. They use their long whiskers as feelers, poking through the soft, silty bottom. Their preference for this type of feeding means that they do not often stray into very deep water, depths of 980 feet (300 meters) at most. When they are yearling pups, however, they are more adventurous and will dive as deep as 1,480 feet (450 meters).
Bearded Seals give birth to their pups on small ice floes floating in shallow waters. They’ll swim for the first time only hours after being born, and if everything goes well will grow at a rate of 7 pounds (3 kg) per day. The mating cycle begins again when the pups are close to being weaned, but mothers are still protective of their pups even after they begin to ovulate. Like the Baikal Seal, Bearded Seals have delayed implantation, which means that while the total gestation time is 11 months, their active gestation time (after the blastocyst has implanted) is only 9 months. Male Bearded Seals will “sing” during the mating season, hoping to attract females and warn off any rival males.
In general, Bearded Seals are solitary. Even in high population densities they will live apart from each other, only coming together during the mating season. Though they are not considered to be a threatened species, like other animals that live in the Arctic they face danger from overfishing and climate change.
The weather out here is so hot and dry that even some of my succulents shriveled up and died. I had to go get some replacements today and move my plants further into shade. Let’s cool off with some pinnipeds.
The Brown Fur Seal (Arctocephalus pusillus) is the seal you all know from those countless Great White Shark documentaries - the ones that show the sharks breaching the surface of the water off the coast of South Africa, hunting these very seals as they venture out to open waters for food. Brown Fur Seals go by different names, including common names for the two subspecies, like the South African fur seal, the Cape fur seal, and the Australian fur seal. They are the largest of all fur seals, stocky in build and with broad skulls. Their vibrissae (whiskers) can grow so long that they point past their ear flaps.
The largest Brown Fur Seals, A. p. pusillus, are found on the African coastlines, primarily South Africa. Males can grow up to 7.5 feet (2.3 meters) in body length and weigh up to 660 pounds (300 kg). Females are smaller, growing up to 5.9 feet (1.8 meters) and weighing 260 pounds (120 kg). Their cousins, A. p. doriferus, are on average slightly smaller, and found primarily along the Australian coastlines. Despite their different ranges, though, the two subspecies share many of the same behaviors.
Brown Fur Seals feed primarily on fish, squid and crab, in that order. They have been known to branch out to other cephalopods like octopus, and even the occasional bird, but approximately 70% of their diet consists of different kinds of fish. They can dive as deep as almost 700 feet (204 meters). As mentioned, they are preyed upon by Great White Sharks, but have developed some tactics to help them survive these predators. There is safety in numbers, so they will swim in large groups when they can, as the sharks like to go after lone individuals. When they swim along the surface, they will “porpoise,” which increases their ability to keep watch under the water. If a group of them is attacked by a shark, they will scatter, going in all different directions to confuse the shark and increase the odds that they will all escape. When in close quarters with a shark, they will stick as close as they can to the shark’s dorsal fin, staying out of reach of its powerful jaws until the shark tires and gives up.
During the mating season, Brown Fur Seals will haul up on rocky shores, gathering into huge rookeries ranging from 500 to 1,500 in number. Though most of their lifespan is spent at sea, they are never too far away from land, and the shores and shallow waters are ideal for new mothers and pups to spend some time together. Breeding starts in October, when the big males haul out and start establishing dominance with each other. During this time they will fast until the end of the breeding season, around December, to protect their females from being mated with by other males. However, females are free to choose which males they mate with, and can wander to another male’s harem if they like him better. Pups are born after a gestation period of almost 12 months, just in time for their mothers to be ready to breed again.
Brown Fur Seals are incredibly curious, and will often approach photographers and scuba divers when they are at ease, though this is more likely to happen in the water, where they have more maneuverability and therefore more opportunity to escape. Though in the past they were hunted, they been protected in Australia since 1923, and in South Africa since 1990. However, they are still hunted in Namibia.
The Australian Sea Lion (Neophoca cinerea) is the only species in the genus Neophoca, and can be found along the southwestern coastlines of Australia. They are among the most endangered pinnipeds in the world, with only 10,000 to 12,000 animals in the remaining population. They were hunted almost to extinction for their hides and oil in 18th and 19th centuries - at the time their range extended to Bass Island.
Adult male Australian Sea Lions are larger than adult females, and aside from the size difference they are easily distinguished by different coat colors. Males are mostly dark brown with a blond “mane” around their head and shoulders. The coats of the females are lighter in color, which range from blond to tan to silver-gray. Males can grow up to 8 feet (2.5 meters) in body length and weigh 660 pounds (300 kg). Females grow up to 6 feet (1.8 meters) in body length, and only reach weights of up to 230 pounds (104 kg).
It’s likely that Australian Sea Lions feed on crustaceans, cephalopods and fish, though little is known about their specific diet. It’s possible that they hunt and eat penguins as well. Males will typically venture further from shore and dive to greater depths than females. One male was observed to dive to a depth of 800 feet (245 meters). Great White Sharks have been known to prey on Australian Sea Lions, and they can drown when entangled in crayfish pots and shark nets.
Breeding cycles between colonies of Australian Sea Lions are not synchronized, which is unusual for pinnipeds. Bulls do not have established territories and are constantly fighting with other males for the right to breed with groups of females during the breeding season. The gestation period of female Australian Sea Lions is almost eighteen months, after which she will give birth to a single pup. Australian Sea Lions practice alloparenting, which means that orphaned pups will be cared for/adopted by others. Pup mortality is as high as 40%, because dominant males have been known to kill pups, and when the males keep their females in such small groups, the females can become aggressive as well.
It’s believed that the feces of Australian Sea Lions provide valuable nutrients to the local ecosystem. The bacteria found in the feces is very efficient in breaking down the waste into forms that are easily absorbed by coastal ecosystems. The Australian government is currently running a recovery program to help sustain and hopefully increase the overall population of Australian Sea Lions.