How do howler monkeys get away from preditors?

Howler monkeys live high in the tree canopy, where there are few predators. However, they don't jump from branch to branch like most monkeys, instead they climb branch to branch. Therefor, I don't believe that howler monkeys can easily escape their predators. One of the predators of the howler monkeys are Harpy eagles, against which howler monkeys have no defense except to hide.