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Mom and Pup
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| [Note Guidelines] Photographer's Note |
This photo was taken at the Ano Nuevo State Reserve.
Elephant Seal
Mirounga angustirostris
Birth
In late December, the females begin to arrive and form "harems" on the beaches of the Reserve. Much smaller than the males, they average ten to twelve feet in length and weigh 1,200 to 2,000 pounds. Three to six days after she arrives, the female gives birth to the pup that was conceived the previous year. Normally only one pup is born to each female, and she nurses for 25 to 28 days.
Nursing
Ordinarily, a mother nurses her own pup, although if they are separated, another female may adopt the youngster. Feeding on its mother's rich milk (55% fat), the pup grows from approximately 75 pounds at birth to 250-350 pounds in less than a month. Some resourceful pups nurse from two or three females. They can weigh 600 pounds and are aptly called "super weaners".
Mating and Gestation
Females come into season and mate about 24 days after giving birth. However, the fertilized egg does not implant in the wall of her uterus for about four months, a rare phenomenon called "delayed implantation". The theory is that the female is so weak after nursing and fasting that she doesn't have enough energy to nourish the egg. Since the seals' gestation period is seven months, this delay means that the young will be born after the female reaches her breeding ground the following year. The pups could not survive if born at sea. Adult females may mate several times before returning to the ocean, abruptly weaning their pups by desertion. By mid-March, most of the adult seals are gone, leaving the pups behind.
Listen to some elephant seals vocalizations.
Source |
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