Primates are more resilient than other animals to environmental ups and downs

December 01, 2010

Durham, NC -- What sets mankind's closest relatives -- monkeys, apes, and other primates -- apart from other animals? According to a new study, one answer is that primates are less susceptible to the seasonal ups and downs -- particularly rainfall-- that take their toll on other animals. The findings may also help explain the evolutionary success of early humans, scientists say.

The study appeared online in the November 30 issue of American Naturalist.

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

To find out how well primates cope with this unpredictability compared with other animals, researchers working at the National Evolutionary Synthesis Center (NESCent) in Durham, N.C. analyzed decades of birth and survival data for seven species of wild primates: muriqui monkeys and capuchin monkeys in Central and South America, yellow baboons, blue monkeys, chimpanzees and gorillas in Africa, and sifakas (lemurs) in Madagascar.

Collecting this data was no small effort. Nearly every day for more than 25 years, seven research teams working around the world have monitored the births, lives, and deaths of thousands of individual primates.

Thanks to a new database developed at NESCent, the scientists were able to pool their painstakingly-collected data and look for similarities across species.

When they compared year-to-year fluctuations in primate survival to similar data for other animals -- namely, two dozen species of birds, reptiles, and mammals -- they found that 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," said co-author Susan Alberts, a biologist at Duke University and associate director at NESCent.

A number of traits may help shield primates from seasonal ups and downs. "For one thing, they're social," said co-author Karen Strier, an anthropologist at the University of Wisconsin-Madison. Primates live in groups and share information with each other, so they're better able to find food and water in times of scarcity, Strier explained.

Primates also owe their adaptability to broad, flexible diets that enable them to adjust to seasonal shortages of their favorite foods. "Primates will eat leaves, grasses, fruits, flowers, bark, and seeds. They're generalists," said Alberts.

In the distant past, similar traits may have also buffered other primates -- namely, humans -- against environmental ebbs and flows, scientists say.

"Modern humans have all the same traits these primate species have: we're smart, we have social networks, and we have a broad diet," said Morris. "Modern humans also arose during a period when Africa's climate was changing," Morris added. "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."

If primates are good at coping with environmental ups and downs, then why are so many of them now endangered? Despite being well buffered from changing weather, human activities still take their toll, the scientists say. With nearly half of the world's primates now in danger of becoming extinct due to hunting and habitat loss, continued monitoring will be key, Strier addded.

"Everything we can learn about them now will help prevent their extinction in the future."
-end-
Study authors (in alphabetical order) and their areas of expertise are:
Susan Alberts (Duke University) -- baboons, Kenya
Jeanne Altmann (Princeton University) -- baboons, Kenya
Diane Brockman (University of North Carolina-Charlotte) -- lemurs, Madagascar
Anne Bronikowski (Iowa State University) -- demography and life history
Marina Cords (Columbia University) -- blue monkeys, Kenya
Linda Fedigan (University of Calgary) -- capuchin monkeys, Costa Rica
William Morris (Duke University) --demographic and ecological analysis
Anne Pusey (Duke University) -- chimpanzees, Tanzania
Tara Stoinski (Dian Fossey Gorilla Fund International and Zoo Atlanta) -- gorillas, Rwanda
Karen Strier (University of Wisconsin-Madison) -- muriqui monkeys, Brazil

Additional images of the seven primate species included in this study are available through the Eurekalert! Multimedia Gallery.

CITATION: Morris, W., J. Altmann, et al. (2010). "Low demographic variability in wild primate populations: fitness impacts of variation, covariation, and serial correlation in vital rates." American Naturalist 177: http://www.journals.uchicago.edu/doi/full/10.1086/657443.

The National Evolutionary Synthesis Center (NESCent) is a nonprofit science center dedicated to cross-disciplinary research in evolution. Funded by the National Science Foundation, NESCent is jointly operated by Duke University, The University of North Carolina at Chapel Hill, and North Carolina State University. For more information about research and training opportunities at NESCent, visit www.nescent.org.

National Evolutionary Synthesis Center (NESCent)

Related Primates Articles from Brightsurf:

When new males take over, these female primates hurry up and mature
Most mammals--including humans and other primates--reach sexual maturity early or late depending on lots of different factors, such as how much food there is to eat.

Primates aren't quite frogs
Researchers in Japan demonstrated for the first time the 'spinal motor module hypothesis' in the primate arm, wherein the brain recruits interneuronal modules in the spinal cord rather than individual muscles to create movement and different modules can be combined to create specific movements.

Researchers reversibly disable brain pathway in primates
For the first time ever, neurophysiologists of KU Leuven, Harvard and the University of Kyoto have succeeded in reversibly disabling a connection between two areas in the brains of primates while they were performing cognitive tasks, or while their entire brain activity was being monitored.

The larynx has evolved more rapidly in primates
The larynx is larger, more variable in size, and has undergone faster rates of evolution in primates than in carnivores, according to a study published August 11, 2020 in the open-access journal PLOS Biology by Daniel Bowling of Stanford University, W.

Single-shot COVID-19 vaccine protects non-human primates
A leading COVID-19 vaccine candidate, developed at Beth Israel Deaconess Medical Center, creates the groundwork for a newly launched COVID-19 vaccine clinical trial.

Research bias may leave some primates at risk
Recent primate research has had a heavy focus on a few charismatic species and nationally protected parks and forests, leaving some lesser known primates and their habitats at risk, according researchers at The University of Texas at Austin and Santa Clara University.

Showy primates have smaller testicles
Well-adorned or well-endowed -- but not both. Evolutionary biologists at the University of Zurich have for the first time demonstrated that male primates either have large testicles or showy ornaments.

Short birth intervals associated with higher offspring mortality in primates
Shorter intervals between primate births are associated with higher mortality rates in offspring, finds a new study of macaque monkeys.

HIV vaccine protects non-human primates from infection
New research shows that an experimental HIV vaccine strategy works in non-human primates.

Oldest-known ancestor of modern primates may have come from North America, not Asia
A new fossil analysis suggests the earliest-known ancestor of modern primates may have come from North America, not Asia, as previously thought.

Read More: Primates News and Primates Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.