Then, at 3 years old, the male calves will go off to live with the male herd. At 15, the male will start to mate. Females will mate as soon they reach 5 years old. Walruses can live up to 40 years.alruses can swim on average around 4.35 mph (7 km/h) and as fast as 21.74 mph (35 km/h), according to the MarineBio Conservation Society. A group of walruses is called a herd. They gather by the hundreds to sunbathe on the ice. During mating season, walruses amass by the thousands.