Study: Primates best at coping with change

To find out how well primates cope with unpredictability, compared with other animals, researchers at the National Evolutionary Synthesis Center in Durham, N.C., analyzed decades of birth and survival data for seven species of wild primates, a center release reported Wednesday.

"Wild animals deal with a world that's unpredictable from year to year," study lead author Bill Morris, a biologist at Duke University, said. "The weather can change a lot; there can be years with plenty of food and years of famine."

When the researchers compared year-to-year fluctuations in primate survival to similar data for two dozen species of birds, reptiles, and other mammals, they found primate survival remained more stable despite seasonal variation in rainfall.

"Primates appear to be well buffered against fluctuations in weather and food availability relative to a lot of other animals," co-author Susan Alberts, also a biologist at Duke, said.

Primates have traits that may help shield them from seasonal ups and downs, Karen Strier, an anthropologist at the University of Wisconsin-Madison, said.

"For one thing, they're social," she said. "Primates live in groups and share information with each other, so they're better able to find food and water in times of scarcity."

Broad, flexible diets enable primates to adjust to seasonal shortages of their favorite foods.

"Primates will eat leaves, grasses, fruits, flowers, bark, and seeds. They're generalists," said Alberts.

"Modern humans have all the same traits these primate species have: we're smart, we have social networks, and we have a broad diet," Morris says. "So the same traits that allow non-human primates to deal with unpredictable environments today may have contributed to the success of early humans as well."

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