The dragon’s blood tree (Dracaena draco) has a thick red resin that makes the plant appear to be bleeding when it is cut. These subtropical plants form huge umbrella-like canopies and can grow for hundreds of years, but they are currently listed as Vulnerable by the IUCN due to the trademark resin being used in traditional medicine, violin staining, and even for embalming the dead.

Overhunting is one reason for wildlife population decline, but do these animals even know what we’re doing to them? New research suggests that they do. Woolly monkeys in the Amazon were observed to react differently to people in their territory, depending on the behavior of the human.

In areas where hunting is heavy, humans gathering food or performing research do not elicit much of a response from the monkeys. Hunters, however, result in the monkeys becoming very quiet and motionless. In quieter areas where human contact is less frequent, the monkeys are more wary of the researchers and gatherers. This indicates that the monkeys are behaving based on experience.

The long term advantage of this behavior is uncertain. Woolly monkeys are highl ...