What characteristic is commonly associated with primates?

Long gestational periods are commonly associated with primates, as they usually give birth to single offspring or, in some cases, twins, allowing for greater parental investment in the young. This characteristic is significant because it enables the lengthy development of the brain and body, which is crucial for the complex social structures and behaviors often seen in primate species.

In particular, primates tend to have larger brains relative to their body size compared to other mammals, facilitating advanced cognitive functions and social interactions. The extended gestation period also allows for offspring to be born at a more developed stage, supporting their survival in diverse environments.

The other options do not reflect general characteristics of primates. Primates do not have the ability to fly, as that trait is specific to certain groups of animals like birds and bats. Additionally, primates are warm-blooded, not cold-blooded, further distinguishing them from reptiles and amphibians. While some primate species might display territorial behavior, it is not a defining characteristic across the entire order, as their social structures can vary widely, including cooperative and non-territorial dynamics.