1 / 3
2 / 3
3 / 3
The Steller’s Sea Cow is an extinct sea cow species living near the North Pacific coast. It was the largest member of its order, Sirenia, and was named after the person who discovered this animal, Georg Wilhelm Steller. It was a relative of the modern-day dugong(Dugong dugon) and has many physical features that are also seen in these animals today. The species went extinct in 1768, likely due to sailors hunting them for meat and fat.
Steller's sea cows are reported to have grown to 8 to 9 m long as adults, much larger than modern-day manatees and dugongs. Their size made them the largest aquatic animal during the Holocene epoch. Their head was small compared to their body size. Their mouth was small and toothless and their eyes were quite small. Like modern-day manatees, these animals also might have whiskers. Its skin was brownish-black, with white patches on some individuals. It was smooth along its back and rough on its sides, with crater-like depressions most likely caused by parasites. This rough texture made people think their skin was made of bark. They also had double lips, allowing them to grasp kelp and other seagrass. Their flippers had bristles on them. Steller, in his description, suggested that they utilized their forelimbs for tasks like swimming, walking on the shallow waters of the ocean, fighting and even digging for algae.
Steller’s sea cows are related to manatees and dugongs, with dugongs being their close relative. Steller described the sea cow as being highly social. It lived in small family groups that helped injured members and were also apparently monogamous. Steller's sea cow may have exhibited parental care, and the young were kept at the front of the herd for protection against predators. Mating season occurred in early spring and gestation took a little over a year, with calves likely delivered in autumn, as Steller observed a greater number of calves in autumn than at any other time of the year. Since female sea cows had only one set of mammary glands, they likely had one calf at a time. These mammals were herbivores like other sirenians. Their main food source was kelp. Steller's sea cow only fed directly on the soft parts of the kelp, which caused the tougher stem and holdfast to wash up on the shore in heaps. The sea cow may have also fed on seagrass, but the plant was not common enough to support the population and could not have been the sea cow's primary food source.
Steller’s sea cows went extinct due to people hunting them. It has been noted that the extinction of the sea cow has been triggered just by hunting for their meat and skin. The fat could be used for cooking and as an odorless lamp oil. The thick, leathery hide could be used to make clothing, such as shoes and belts, and large skin boats sometimes called baidarkas or umiaks. The decline of Steller's sea cow may have been an indirect effect of the harvesting of sea otters by the area's aboriginal people. With the otter population reduced, the sea urchin population would have increased, in turn reducing the stock of kelp, its principal food.