Lemurs that love fruits have higher memory power than their counterparts which are depended on a more varied diet.
According to the researchers from Duke University, the research findings support the idea that depending on seasonal food items help in improving certain cognitive skills including memory.
The study is part of an effort to understand the origins of primate intelligence. ”Our results suggest that different cognitive skills might evolve for different reasons,” researchers Alexandra Rosati noted in a statement.
For testing the memory power among the lemurs, researchers Alexandra Rosati at Yale University and Kerri Rodriguez and Brian Hare carried study on five species of lemurs residing in captivity at the Duke Lemur Center.
The five species of lemurs used for the study include fruit-loving red-ruffed and black-and-white ruffed lemurs, leaf-consuming Coquerel’s sifakas, and ring-tailed and mongoose lemurs that consume a combination of fruit, leaves, seeds, flowers, nectar and insects.
Lemurs live in social groups that consist of two to 16 animals. They stay within a common home range. The researchers mainly wished to keep a track on how many of the lemurs were able to recall the incidents.
The researchers made the lemurs to learn the position of food placed in one of two arms of a T-shaped maze during the first experiment. A week later, what they found that the fruit-loving ruffed lemurs were the only species able to remember the location of the food.
In the second experiment, the researchers ascertained that whether the lemurs were remembering the exact location of the food or just recalling them.
The experiment was repeated, but ten minutes after learning the location of the food the lemurs were placed in a new starting location.
Following the study, the researchers concluded that the ruffed lemurs were most likely to find the right spot again, even though they had to follow a new path to locate the food
In the third experiment, the researchers determined the lemurs’ ability to recall several locations. For the study, they allowed a lemur to investigate a room containing eight open boxes, each marked with a visual cue. 50 percent of the boxes contained food and the fifty percent were empty. After the lemur learned which boxes contained food and which didn’t, the researchers placed food in all eight boxes and placed the lids on the boxes to prevent the lemur from seeing the food. When each lemur investigated the room again, the ruffed lemurs preferentially investigated locations where they discovered food before.
According to researchers, ruffed lemurs’ diets can be 90 percent or more fruit.
The findings of the study were published in the journal Animal Cognition.