A recent study has shed light on the remarkable tool-using behavior of southern sea otters and its impact on their ability to thrive in a changing marine environment. Researchers from The University of Texas at Austin, the University of California, Santa Cruz, Monterey Bay Aquarium, and other institutions closely observed 196 radio-tagged southern sea otters off the coast of California to unravel the role of tool use in the otters’ foraging habits and dental health.

The findings, published in the journal Science, unveiled that individual sea otters, particularly females, utilize tools such as rocks, shells, and even trash to access larger and harder-shelled prey, thereby reducing tooth damage during feeding. Chris Law, a postdoctoral researcher at UT Austin, emphasized the significance of this behavior, especially for female otters who rely on efficient foraging to meet their energy demands, particularly during the demanding period of raising pups.

In the coastal regions of Central California, sea otters’ preferred prey, such as large abalone and sea urchins, have become scarce, prompting the otters to turn to alternative prey with hard shells, which can pose a risk to their dental health. The study revealed that tool use allowed individual otters, especially females, to access a wider variety of prey, reducing the impact of tooth damage and ensuring their ability to meet their energy needs.

The research also highlighted the critical role of tool use in mitigating the trade-offs between accessing different types of prey, maintaining tooth condition, and meeting energy requirements, particularly in environments where preferred prey are scarce. This behavior has proven to be essential for the survival of some otters, especially in the face of diminishing food resources.

The study’s findings provide valuable insights into the adaptive behavior of southern sea otters and underscore the importance of understanding and preserving this threatened species, which plays a crucial role in marine ecosystems by preying on sea urchins that feed on kelp forests.

References

• Law, C. J., Tinker, M. T., Fujii, J. A., Nicholson, T., Staedler, M., Tomoleoni, J. A., Young, C., & Mehta, R. S. (2024). Tool use increases mechanical foraging success and tooth health in southern sea otters (Enhydra lutris nereis). Science, 384(6697), 798–802. https://doi.org/10.1126/science.adj6608
• University of Texas at Austin. (2024, May 16). Sea otter study finds tool use allows access to larger prey, reduces tooth damage. Phys.Org; University of Texas at Austin. https://phys.org/news/2024-05-sea-otter-tool-access-larger.html