Bigger brains mean better problem-solving skills in carnivores: study

Carnivore species with larger brains relative to their body size might have better problem-solving skills, a U.S. study suggested Monday.

Despite decades of research, the relationship between brain size and intelligence remains highly debated. But the new study, published in the U.S. journal Proceedings of the National Academy of Sciences, supported the theory that species with brains that are large relative to their body are more intelligent.

Sarah Benson-Amram, assistant professor from the University of Wyoming, and colleagues, described a massive experiment, during which 140 animals from 39 different mammalian carnivore species in nine different U.S. zoos were presented with a novel problem-solving task.

The study included polar bears, arctic foxes, tigers, river otters, wolves, spotted hyenas and some rare, exotic species such as binturongs, snow leopards and wolverines.

Each animal was given 30 minutes to try to extract food from a metal box, closed with a bolt latch.

The box was scaled to each animal's body size and baited with the study animal's favorite food, so red pandas received bamboo and snow leopards got steak.

Overall, 35 percent of animals, or 49 individuals from 23 species, were successful in solving the problem, the study found.

The bears were the most successful, solving the problem almost 70 percent of the time, while meerkats and mongooses were the least successful, with no individuals from their species solving the problem.

Thus, the researchers concluded that species with larger brains relative to their body size were more successful than species with relatively smaller brains on solving the task.

"This study offers a rare look at problem solving in carnivores, and the results provide important support for the claim that brain size reflects an animal's problem-solving abilities -- and enhance our understanding of why larger brains evolved in some species," Benson-Amram said in a statement.

Interestingly, larger animals were less successful overall than smaller-bodied animals.

In addition, the study showed that neither manual dexterity nor living in larger social groups improved problem-solving success. Endit