Long-term study shows reduced survival and longer lactation in endangered sea lions after a marine heatwave, suggesting critical trade-offs in maternal care.
Key Points
This study investigates the effects of the 2014-2016 marine heatwave on the behavior and survival of endangered Steller sea lions.
Conducted a long-term individual-based study on Steller sea lions in the Gulf of Alaska.
Estimated vital rates using robust design multi-state mark-recapture statistical methods.
Assessed changes in maternal attendance, survival rates, and reproductive behaviors over multiple years.
Adult female survival rates dropped from approximately 93% to 77% for mothers and 85% for barren females post-heatwave.
Reproductive rates decreased from over 70% before 2016 to about 60% during 2016-2018, with more females skipping birth years.
Juveniles suckled longer than one year, indicating extended lactation, which posed risks to adult female survival.