- Habitat loss and fragmentation: The main cause of the decline in yellow-tailed woolly monkey populations is the destruction of their natural habitat. The tropical rainforests where they live are being cleared for logging, agriculture, cattle ranching, and mining. This deforestation disrupts the monkeys' food and shelter and makes them vulnerable to hunting.
- Hunting and poaching: Yellow-tailed woolly monkeys are hunted for their meat, fur, and as pets. They are also sometimes killed as pests because they can raid crops.
- Climate change: Climate change is causing the habitat of the yellow-tailed woolly monkey to change rapidly. The increased temperatures and changing rainfall patterns are affecting the availability of food and shelter for the monkeys.