She defends and protects her calf and may shelter it under her chest between her foreflippers. Calves often ride on their mothers' backs in the water. There is some evidence that females may care for orphans, although it is unknown whether the female nurses the orphan. G. Calf growth and development. Growth rates gathered in zoological environments are considered to be indicative of the growth rates of free-living walruses.
Males grow slightly faster than females.
By one month of age, calves are strong swimmers. A pregnant, near-term cow and her calf from the previous pregnancy usually separate in late April, just before the new calf is born. Mother and calf stay together two years or longer if the mother doesn't produce another calf. Young males may stay an additional two or three years before joining an all-male herd. Females tend to stay with the same herd.