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Whales in San Francisco Bay

Roughly 30 gray whales have been spotted in the Bay this season, many more than is typical. Sadly, there have also been at least 14 deaths this year, which is more than in all of 2024. 

We are investigating to help determine the cause of these deaths. By gaining insights into what is causing these tragedies, we can better understand how to help prevent them.

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gray whale fluke
two California sea lion pups vocalizing

Social Interactions of Stranded and Recovering Immature California Sea Lions

Social Interactions of Stranded and Recovering Immature California Sea Lions (Zalophus californianus)
  • Behavior

Abstract

Hundreds of California sea lions (Zalophus californianus) strand along the Pacific coast of North America each year. They are treated for a variety of conditions at marine mammal clinics along the coast, including malnutrition, physical trauma, infections, and toxicosis. The largest clinic is The Marine Mammal Center (TMMC) in the Marin County Headlands just north of San Francisco where sea lions can reside for weeks to months before release. Assessment of illness and recovery can be difficult. Since healthy sociality is sensitive to developmental impairment and illness, understanding of typical social interactions would aid in the assessment of overall recovery. To gain insight to the social behavior of captive California sea lions, we examined the behaviors of recovering immature individuals at TMMC. We found that the sea lions in male pens were generally more physically active, expressing more approach interactions and coordinated swimming per day. The sea lions in mixed-sex pens fluctuated in activity, with the level of activity decreasing as the day went on; while the sea lions in male pens maintained similar levels of activity all day. These findings offer a foundation for more rigorous studies of the social neurobiology of recovering California sea lions.


Meyer, M.S., Rickert, S.S., Pearce, H.L., Khan, O.A., van Bonn, W., Johnson, S.P., Lahvis, G.P. 2017. Social interactions of stranded and recovering immature California sea lions (Zalophus californianus). Aquatic Animals. 43(5): 517-529.

behavior

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