California Sea Lion

Zalophus californianus

This carcass was found on Nye Beach in Newport, Oregon. The cause of death is unknown, but PCB toxicity is suspected. PCBs are produced by dinoflagellate plankton and bio-amplified up the food chain. The carcass was moved to a secure location but left exposed so flies could lay their eggs on it. The developing fly larvae consumed the muscle tissue and left most of the bones clean. It took volunteers three years to reassemble and mount the bones.
In this skeletal articulation, notice how the vertebral column curves. This shape shows how sea lions swim, moving their whole backbone in an up-and-down motion and propelling forward with their powerful front flippers. Notice the ridge (sagittal crest) on the skull and shoulder blades, which are used for large muscle attachment.
Also, notice that taxidermy foam was used along the vertebral column to simulate discs, which are not generally well preserved.

california_sea_lion-400x223.jpg

Adult Size: Males are much larger than females and can reach lengths of nearly nine feet long and 1,153 pounds.
Life Span: 15-20 years
Feeding Habits: Their diet varies greatly and includes squid, a wide variety of fish and clams. This food is all foraged along coastlines, the continental shelf and sea mounts. Outside the mating season, males and females separate so they don’t compete for food.
Mating and Offspring: Mating occurs in California’s Channel Islands. From May to August, males establish a territory and attempt to gather as many females as possible to mate. Females have a 12-month reproductive cycle, which includes a nine-month gestation and a three-month delayed implantation period. Most young are born in June or July.
Frequency and Abundance Oregon Coast: In Yaquina Bay and on Oregon’s coast, the vast majority of California sea lions are males. They are abundant from September to May. Females are rarely in Oregon and generally stay close to their breeding rookeries in California.