It’s shark season at the Farallon Islands!

Every fall, the white sharks return to the Farallon Islands from their annual migration to the middle of the Pacific Ocean. We typically see the first shark predation event during late August, and then the number of predations increase through September to when they peak in October.


Observing white shark predation

In the fall, sharks migrate to the coast of California, including the Farallon Islands, to feed on pinnipeds (seals or sea-lions) when the abundance of immature animals is at its peak. This gives us a unique opportunity to study them. On September 27 as we were watching from the Lighthouse atop Southeast Farallon Island, a swarm of gulls began to circle and a pool of blood was observed in Fisherman’s Bay, indicating that a shark had just found a meal.


Lighthouses and Migrants

For the first few decades that PRBO worked on the Farallones, a powerful rotating light on the lighthouse acted as a beacon to lost ships, birds, and bats.  An analysis of 38 years of hoary bat arrivals on the island revealed that nights during the dark phases of the moon had a greater likelihood of