Azara's owl monkeys, a small primate species found in South America, are heavier today than those that lived a quarter-century ago, and evidence suggests that rising temperatures might have driven the ...

Researchers have been weighing the same group of wild primates in the Gran Chaco region of northern Argentina for almost 25 years. It turned out to be far more revealing than just routine fieldwork.

Azara’s owl monkeys, a small primate species found in South America, are heavier today than those that lived a quarter-century ago, and evidence suggests that rising temperatures might have driven the ...

A quarter-century of tracking wild owl monkeys, often referred to as night monkeys, in Argentina has turned up something unexpected: the small, leaping primates are getting heavier. And researchers ...