Last summer, Lauren Highfill discovered that sea lions are not the most agreeable study participants. Over three months, Highfill, a third-year experimental psychology student at the University of Southern Mississippi, persuaded only one sea lion to complete her experiment, which explored the animals' ability to understand human communication. She had to dismiss her second sea lion after the animal gave birth to a pup. And after a heat wave hit, six more sea lions at Austria's Vienna Zoo refused to participate, as they adopted a strict schedule of all-day napping.
"I was even attacked by the pregnant animal, but overall it was a good learning experience," says Highfill. "I learned that you need to allot a lot more than three months for an animal study."
Perhaps more importantly, Highfill also garnered preliminary evidence that these marine mammals have a grasp of human communication skills.
In her study, the one compliant sea lion, an eight-year-old female named Zwerg, learned that she would be rewarded if she touched her nose to either of two flower pots. Then, during the experimental phase, she watched as a trainer pointed at one of two flowerpots. Zwerg then touched her nose to one of the pots, picking the indicated one 79 percent of the time. When the trainer specified the correct flowerpot by looking at it, Zwerg chose correctly 83 percent of the time.
The findings suggest that sea lions may be able to understand that other animals know something they don't, a foundation for a theory of mind, says Highfill. And though sea lions don't have hands to point out things to one another, they seem to easily understand human pointing.
"It's interesting that their brain functions at a level where they can somehow respond correctly to cues they shouldn't naturally respond to," she says. "They might have been exposed to it from watching human interactions."
-S. Dingfelder