They are capable of rotating their hind flippers forward in order to have full use of all four limbs on land. Steller's Sea Lions show remarkable sexual dimorphism. Males are much larger than females. The length of the average male is 282 centimeters, while the length of the average female is only 228 centimeters. The weight of the average male is 566 kilograms, while the weight of the average female is only 263 kilograms.
Males also have extremely thick muscular necks and a mane of coarse long hair.
Newborn pups are about 100 centimeters long, weigh 16-23 kilograms, and have a thick, dark brown pelage that molts to lighter after six months. Food Habits Steller's Sea Lions are known to be true carnivores. Commercially exploited walleye pollack is an important part of their diet. May. Males establish a harem of 3-20 females and a territory surrounding them. The pups from the preceding season are born from late May to early June.