A study led by researcher Alexandra Childs sheds light on a fascinating behavior observed in Galápagos sea lions. The research, recently published in the American Naturalist journal, reveals that around 11% of the sea lion population continues to nurse from their mothers well into adulthood, a phenomenon dubbed “supersuckling.”
Childs, a PhD candidate in behavioral and marine biology at the University of Bielefeld in Germany, expressed astonishment at the sight of fully grown sea lions nursing. The behavior defied expectations, with some individuals nursing up to 16 years old, akin to humans breastfeeding into their 60s.
The study, spanning 20 years of data on Galápagos sea lions (scientifically known as Zalophus wollebaeki), found that most individuals weaned from their mothers between 1.5 and 4.5 years of age. However, supersucklers continued nursing beyond this age range.
While this behavior is observed in other sea lion species and seals, the extent of supersuckling in Galápagos sea lions is particularly pronounced. This behavior is believed to be linked to ensuring offspring survival and reproduction during periods of food scarcity, though the study noted an increase in supersuckling during times of ample food resources.
Further research is needed to fully understand the reasons behind this behavior, which could range from immunological benefits to social bonding mechanisms. The study underscores the need for continued exploration into the intriguing behavior of Galápagos sea lions.
