Small Sea Lions with Big Personalities
Some Galapagos sea lion pups are bold, whereas others are shy.
Article body copy
For the first time, researchers have shown that Galapagos sea lion pups have distinct personalities. The discovery offers new insights and opportunities for the conservation of these endangered sea lions, which breed almost exclusively on the Galapagos Islands off Ecuador.
Over the past two decades, the study of animal personality has exploded. Galapagos sea lions are joining a range of animals—from spiders and mice to octopuses, monkeys, and dolphins—shown to have demonstrable personality traits. For an animal to scientifically qualify as having a personality it needs to exhibit consistent individual differences in behavior that can’t be explained by age, sex, or size.
By understanding Galapagos sea lions’ personalities, says Eugene DeRango, a biologist at Bielefeld University in Germany and lead author of the new study, “we can examine differences in behavior to look at how it impacts an animal’s survival and how they go about their daily lives.”
To determine if Galapagos sea lions have distinct personality traits, DeRango and his team tested how 73 pups responded to a novel object—a fluorescent tennis ball on the end of a 4.5-meter pole. Some pups bit the ball like puppies, says DeRango, while others fled. The test showed the pups’ penchant for risk-taking behavior—a trait that remained consistent when some of the same pups were later introduced to a human. Pups that were bolder with the tennis ball also showed less fear of humans. To prove these reactions were truly a sign of personality, the scientists confirmed the results in repeat tests a year later.
“While they may all look the same—little, cute, and furry—there’s diversity in their behaviors,” DeRango says.
DeRango also found an interesting correlation between pups and their mothers. Older, fatter moms tended to have bolder pups, though he can’t say why. To figure out if boldness is passed down genetically or learned, DeRango would like to see if bold pups’ moms are also bolder. He also found that shy pups got a boost of confidence in the presence of their mothers.
Realizing that animals have different personalities adds another dimension for conservationists to consider says Sean Twiss, an animal behaviorist at Durham University in England who was not involved in the study.
“Personality is a form of biodiversity,” says Twiss. If new challenges arise, like increasing tourism or rapid environmental change, there’s a greater chance the species will survive if there are a range of personalities because “some portion of that population is going to deal with those challenges,” he says.