For the past five years on Dec. 15, a "Beach Closed" sign is placed across the mid-level stairs leading to Casa Beach (also known as the Children's Pool) as humans vacate to give up the sand for the annual harbor seal pupping season.
Most humans leave the premises readily as the 60 some degree winter coastal waters are quite chilly. Not so constrained, a number of gravid female harbor seals increase their presence on the sandy beach enclosure to nearly full time to prepare for the arrival of their pups, due around February, March, and April. Having "shared the beach" with human recreational activities for the other seven months of the year, the seals need this exclusive use to complete the nine-month gestation period, free from visitors and potential disturbances.
After birth, the mother nurses her pup for six or seven weeks while earnestly showing it all the skills required for survival in their ocean domain. The weaning is firm, and mothers can be seen flipping over when the weaner persists in looking for another easy meal. Females need this free time for their bodies to restore the maternal hormonal balance in preparation for mating season (May to June) to complete the annual reproduction cycle.
The Sierra Club Seal Society docents offer an illustrated "Talk and Walk" at the Mangelsen's Wildlife Images Gallery in La Jolla on a biweekly basis for the general public during this time. For more information on these talks, call the Gallery at 858-551-9553.