Tuesday, October 26, 2021

Young seals arrive

Young seals arrive for Haul-Out

Construction doesn’t faze them

Seals arrive daily on the beach at Piedras Blancas. They are young, both males and females. It’s the Fall Haul-Out, a rest for the young seals between migrations. They’ll continue arriving through October.

Seals fast for the four to six weeks they are on the beach during this autumn retreat. They rely on their blubber to meet their nutritional needs. They have the beach and the surf to themselves, before the adult bulls begin arriving around Thanksgiving for the breeding season. Some may stay on the beach into December.

Heavy equipment

This year, they are accompanied by construction crews. The culvert under the north boardwalk collapsed last January, during the big atmospheric river storm. State parks workers are replacing it. Seals remain nearby, ignoring the workers, who have fenced off their work area.

They will turn to the south boardwalk to replace a culvert after the north boardwalk is reopened. Part of the north boardwalk is open, from the north parking lot. That parking lot also leads to the Boucher Trail, two miles to the Piedras Blancas Light Station. Several points along that trail overlook elephant seal beaches.


The light station is open for tours by reservation only on Tuesdays, Thursday and Saturdays. Book ahead through recreation.gov.

Boisterous boys

The young males are willing to spar with each other, on the sand and in the water. It’s the nature of young guys to roughhouse. Some nose around young females, but they aren’t willing to mate. The ones on the beach are too young, and they have an estrus breeding cycle. Like dogs, they only mate when they are ready.



The seals take a rest between their two annual migrations. The young seals will leave the beach as adult bulls arrive in late November, migrating north and west until time to return to the beach to molt their skin in May. They left the beach in June, returning now. In between, they are diving and feeding, diving and feeding.

Males and females have different feeding strategies. Males migrate north along the coastline, diving to feed at the bottom along the continental shelf. Females migrate to the open ocean, feeding on prey they encounter there.

Males eat bottom-dwelling fish such as dogfish and hagfish, not targets for human tables. Females eat small fish in the mesopelagic layer. They don’t compete with fishermen, so elephant seals aren’t in conflict with them they way sea lions are.

Adult females

Occasionally a mature female, not pregnant, comes on to the beach during Fall Haul-Out. Nearly all mature female seals are pregnant every year, but some skip a year. Exactly why they aren’t pregnant is a subject of active research at Ano Nuevo Reserve and Sonoma State University. Tracking individual seals and understanding what’s going on is difficult, but researchers are making progress.

We had our first adult female satellite tag recovery procedure last week,” Patrick Robinson, director of the Ano Nuevo Reserve said in an email. “She was not pregnant, but otherwise seemed healthy.  We're still learning about these seals that skip breeding!”

 

 

 


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