Gray squirrels are smarter than red squirrels, research shows

When scientists presented the two squirrel species with a pair of tasks designed to gauge an animal's intelligence and problem solving talents, they found the gray squirrel boasted greater cognitive abilities.

The squirrels were faced with both an easy and complex task. The easy task had the animals open a transparent lid to retrieve a treat. The complex task had the squirrels manipulate a more complex series of directional levers to access a reward of hazelnuts.

Both red and gray squirrels were equally adept at the easy task, but gray squirrels were significantly better at solving the second, more complex task.

Roughly nine in ten gray squirrels successfully manipulated the levers, while only six in ten red squirrels were able to retrieve the hazelnuts.

The gray squirrels cognitive advantage may explain why the species, which only arrived in Britain during the 19th century, now outnumber red squirrels -- who've lived there for thousands of years -- some 15 to one.

"Many factors have been considered to explain why grey squirrels are more successful when they move into areas where red squirrels live," Pizza Ka Yee Chow, an animal researcher at the University of Exeter, said in a news release. "These factors include disease resistance and the fact grey squirrels are bigger, but our research shows problem solving could be another key factor for the success of grays."

Scientists suggest problem solving skills may be especially important for invasive species, which must adapt to new environments.

"These results illustrate how investigating animals' differing cognitive abilities can help us understand important issues in conservation," said researcher Stephen Lea.

While red squirrels may not be as good at problem solving, the research -- published this week in the journal Animal Behavior -- suggests they're quick learners.

For the roughly six in ten red squirrels who did solve the puzzle, several were faster than gray squirrels at manipulating the contraption on their second try.