Female Otters Use Tools to Survive a Changing World

A recent study has revealed that sea otters, particularly females, are clever tool users when it comes to snagging their meals. Researchers from The University of Texas at Austin, University of California, Santa Cruz, Monterey Bay Aquarium, and other institutions tracked 196 radio-tagged southern sea otters along the California coast. Their mission was to understand how these otters adapt to a changing environment.

These researchers, along with their volunteer “otter spotters,” kept a close eye on the otters’ tool usage. They observed them using rocks, shells, and even bits of trash to crack open their prey.

This innovative behavior allows otters to feast on larger prey and protects their teeth from damage, especially when their usual food becomes scarce. The study sheds light on the dietary habits and dental health of these fascinating marine mammals, according to The University of Texas at Austin.

Chris Law, a postdoctoral researcher and an Early Career Provost Fellow at UT Austin, who spearheaded the study during his time as a graduate student at UC Santa Cruz, highlighted the significance of this finding.

He explained that sea otters vary in how often they use tools. Females, in particular, rely on tools to compensate for their smaller size and weaker biting strength, ensuring they can meet their energy needs, especially when raising pups.

Otters are more likely to prey on crabs, mussels, and small marine snails

In the coastal regions of Central California, where southern sea otters roam, their favorite foods like giant abalones and sea urchins are usually easy to crack open.

Sea ​​otters are unique in that they are the only marine mammals that use stone tools. They often use rocks to crack open shells while swimming on their backs. pic.twitter.com/qKNQnEpv0I

— Kotobarz (@Kotobarz) March 25, 2024

However, these food sources are becoming scarce. As a result, otters are turning to tougher food sources such as crabs, clams, mussels, and small marine snails. While these might satisfy their hunger, they come with a risk—damaging their teeth while prying them open.

Having healthy teeth is important for otters’ survival. If their teeth wear down or get damaged, they could face starvation. That’s where tools come in handy. By using tools, otters can expand their menu options, ensuring they get enough calories to thrive.

Moreover, the study revealed that female otters tend to have fewer tooth problems compared to male otters.

The research indicates that female otters are more likely to use tools, and those who did were able to tackle tougher or larger prey compared to those who didn’t. In fact, female otters could chow down on prey that was up to 35 percent harder than what males managed to crack open using tools.

This behavior isn’t unique to otters. Female dolphins, chimpanzees, and bonobos also show a preference for tool usage, likely for similar reasons, as reported by The University of Texas at Austin.