Thursday, September 22, 2022

Predators patrol offshore

 

Young elephant seals make a good blubber meal

A local photographer documented orcas offshore theCentral Coast in September. Orca sightings are unusual, although the fact that they are there is not unexpected.

Orcas are known to prey on elephant seals, although it’s not well documented. This happens far at sea, with no humans around to watch.

September is when juvenile elephant seals return to Central Coast beaches. They come to take a month or so of rest, the Fall Haul-Out. Hundreds of them sleep on the beach at Piedras Blancas. Look for size differences, nose development, and scars from prey attacks.



Predators feed on young seals

Great white sharks prey on the juveniles in the Farallon Islands and Tomales Bay in the fall. Perhaps these orcas were here to do the same.

Vincent Shay, the photographer, identified two groups of orcas: one group of four and the other of five. They were likely transient orcas, which feed on marine mammals. 

According to Port Townsend Marine Science Center at Fort Worden State Park, “transients travel and hunt in small groups of 2-6 individuals. These small groups are usually based on a female and her offspring, but often change as animals mature and disperse.”

Evading predators

Elephant seals dive deep, but predators can attack when they come to the surface to breathe. Staying in the dark depths is safer. They feed below their predators’ usual hunting depths. Even traveling between their feeding sites and the rookery, the seals travel in long v-shaped dives, as far as possible below the range of their predators. Researchers call it “the lightscape of fear.”



Sharks and orcas hunt at relatively shallow depths. Orcas are also intelligent and have complex social structures. They hunt cooperatively in groups.

Sharks know when they are outclassed, though. They clear out when orcas swim through. One study found that when orcas showed up in the Farallons, sharks hunting elephant seals relocated to Ano Nuevo and other shark aggregation sites.

At Piedras Blancas in September, seals rest peacefully on the beach, waking up for the occasional match with another young seal. Each one is a survivor of the dangers they face from predators even more fierce than they are.

San Simeon Cove Winter Guides

December through March is elephant seal breeding season. Piedras Blancas rookery is the main local breeding area, but alpha bulls chase less dominant males off those beaches. They often come to San Simeon Cove to rest and recuperate from their battle wounds.



Human visitors and their dogs also come to the cove. The seals are an unexpected wildlife experience for them. Friends of the Elephant Seal guides help to keep both sides safe.

The bulls that come to San Simeon Cove are less dominant only to other, even bigger bulls. They weigh two tons or more. While they are rarely aggressive toward beachgoers, they can be dangerous. Visitors need to keep their dogs from annoying the seals, and stay well back. Seals may challenge each other, or decide to return to the ocean without warning to visitors strolling down the beach.

FES trains volunteers to educate the public and help everyone enjoy visiting the beach. Join them by applying online by October 17. Questions? Call 805-924-1628. Must be 18 or older. Commit to two four-hour shifts a month, December through March. Must be friendly, outgoing, able to stand for three to four hours and walk on the beach in a variety of weather conditions.

https://www.sanluisobispo.com/news/local/environment/article266192816.html