October is a busy month at Piedras Blancas, with hundreds of juvenile seals arriving for fall haul-out. That means they haul themselves out of the surf onto the beach. Most of these seals are less than 5 years old, the age when the males start growing that distinctive nose.
The smallest seals are the young of the year, the pups born in January. Those on the beach have survived their first migration. Only half of the pups make it. They may not have gained much weight, but any seal on the beach is a survivor.
These fat, young seals make a good meal for great white sharks, which migrate to the Central and Northern California coast in the fall. Young seals are more desirable prey than mature bulls, which are formidable opponents and can fight back.
Great white sharks typically attack from below and behind their prey. The relationship between predator and prey is a balance, between attack and avoidance. UC Santa Cruz researcher Sarah Kienle is studying elephant seal feeding behavior at Guadalupe Island off Baja California. Her collaborators have observed that seals returning to that island are likely to approach the beaches from below….