It appears a combination of superior communication allowing socialnetworks and a wide range of dietary options does it. What I find odd is that other animals do notdo exactly the same thing. It is notthat hard. More likely other animals aremore creatures of habit and find it difficult to switch diets because of that.
Primates are simply a little cleverer and are perhaps more prepared toswitch away if necessary. At least thatis the only explanation I can give.
I recall our farm dog eating only what we put in front of him. That included chopped oats which he becamefond of. He also ate berries. Yet he killed groundhogs he would not touch.
What that tells us is that learned behavior can limit the available dieteven when good alternatives exist. Primates are simply better atv overcoming this limitation.
Primates Are More Resilient ThanOther Animals To Environmental Ups And Downs
A number of traits may help shield primates from seasonal ups anddowns. "For one thing, they're social," said co-author Karen Strier,an anthropologist at the University of Wisconsin-Madison. Primates live ingroups and share information with each other, so they're better able to findfood and water in times of scarcity, Strier explained.
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 tothe seasonal ups and downs - particularly rainfall- that take their toll onother animals. The findings may also help explain the evolutionary success ofearly humans, scientists say.
The study appearedonline in the November 30 issue of American Naturalist.
"Wild animalsdeal with a world that's unpredictable from year to year," said study leadauthor Bill Morris, a biologist at
."The weather can change a lot; there can be years with plentyof food and years of famine," he explained. Duke University
To find out how wellprimates cope with this unpredictability compared with other animals,researchers working at the National Evolutionary Synthesis Center (NESCent) inDurham, N.C. analyzed decades of birth and survival data for seven species ofwild 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 datawas no small effort. Nearly every day for more than 25 years, seven researchteams working around the world have monitored the births, lives, and deaths ofthousands of individual primates.
Thanks to a newdatabase developed at NESCent, the scientists were able to pool theirpainstakingly-collected data and look for similarities across species.
When they comparedyear-to-year fluctuations in primate survival to similar data for other animals- namely, two dozen species of birds, reptiles, and mammals - they found thatprimate survival remained more stable despite seasonal variation in rainfall.
"Primates appearto be well buffered against fluctuations in weather and food availabilityrelative to a lot of other animals," said co-author Susan Alberts, abiologist at
and associatedirector at NESCent. Duke University
A number of traits mayhelp shield primates from seasonal ups and downs. "For one thing, they'resocial," said co-author Karen Strier, an anthropologist at the Universityof Wisconsin-Madison. Primates live in groups and share information with eachother, so they're better able to find food and water in times of scarcity,Strier explained.
Primates also owetheir adaptability to broad, flexible diets that enable them to adjust toseasonal shortages of their favorite foods. "Primates will eat leaves,grasses, fruits, flowers, bark, and seeds. They're generalists," saidAlberts.
In the distant past,similar traits may have also buffered other primates - namely, humans - againstenvironmental ebbs and flows, scientists say.
"Modern humanshave all the same traits these primate species have: we're smart, we havesocial networks, and we have a broad diet," said Morris. "Modernhumans also arose during a period when
Africa'sclimate was changing," Morris added. "So the same traits that allownon-human primates to deal with unpredictable environments today may havecontributed to the success of early humans as well."
If primates are goodat coping with environmental ups and downs, then why are so many ofthem now endangered? Despite being well buffered from changing weather, humanactivities still take their toll, the scientists say. With nearly half of theworld's primates now in danger of becoming extinct due to hunting and habitatloss, continued monitoring will be key, Strier addded.
"Everything wecan learn about them now will help prevent their extinction in thefuture." Morris, W., J. Altmann, et al. (2010). "Lowdemographic variability in wild primate populations: fitness impacts ofvariation, covariation, and serial correlation in vital rates."AmericanNaturalist 177.