Size does matter when it comes to animal brains

New York: A mammal's brain size predicts its problem-solving ability, says a study.

Species with large brains were more successful than species with relatively small brains, the study revealed.

"The results of this study provides important support for the claim that brain size reflects an animal's problem-solving abilities and enhances our understanding of why larger brains evolved in some species," said Sarah-Benson-Amram, assistant professor at University of Wyoming in the US.

Species that are more social or live in big social groups are not necessarily better problem-solvers than those that live alone, highlighted the study.

The study represented a step forward in understanding the evolution of problem solving in mammalian carnivores, researchers revealed in the study published in the Proceedings of the National Academy of Sciences.

Researchers tested 140 zoo animals from 39 mammalian carnivore species with a problem-solving task.

Animals such as river otters, wolves, bears, African wild dogs and cheetahs tried to open steel mesh "puzzle boxes" baited with food and adjusted to their body size.

The animals opened the puzzle box using a lever, and if they were successful, they received a food reward in the box.

Overall, 35 percent of animals successfully solved the puzzle, with bears as the most triumphant at completing the task 70 percent of the time. Meerkats and mongooses were the least successful.

Although these species also differed in body size, it was their brain size relative to how big they were that primarily influenced whether they solved the puzzle.

Variables such as the social group size for animals, their manual dexterity or work effort failed to predict success at opening the boxes, the study showed.