A new study has revealed that fruit-eating lemurs are the brainiest of all such animals. The intelligence of lemurs was tested by researchers from Duke University. It was found that the species relying on fruits as their staple food acted smarter than those who were eating a more varied diet.

Sense of spatial memory was more advanced in lemurs that ate fruits compared to other species of the mammal.

Alexandra Rosati from Yale University led the research along with Kerri Rodriguez and Brian Hare of Duke. The researchers included red-ruffed and black-and-white ruffed lemurs in the study. The diet of red-ruffed and black-and-white ruffed lemurs consisted of over 90% fruits.

The spatial memory skills of them were then compared with Coquerel's sifakas along with mongoose and ring-tailed lemurs. These species feed on fruit, seeds, leaves, flowers along with bugs and insects.

In the first experiment, the ability of the animals to remember where food was located in mazes and boxes was tested. The food was hidden in a T-shaped maze.

Only fruit eaters were actually able to remember the location of the sweet treat after a week, compared to their counterparts eating a varied diet.

The researchers wanted to see in the second test whether the animals were able to remember the location or just the turns they made to find the food. Ten minutes after showing where to find the food, the researchers placed the fruit in the same location. The lemurs, however, were given a different starting position this time. "Before they might have turned right, but now they had to turn left to get to the same spot", Rosati said.

This time also, fruit lemurs did much better in the task than other species. This helped researchers reach at the conclusion that fruit-eating lemurs rely on a memory of a place in order to find food, and not just their own actions.