The Big Hyoid Bone:

A big bone in their throat, the hyoid bone, makes howler monkeys' noise great. This significant bone helps them make deep, loud calls that can go three miles through the thick trees.
The hyoid bone in howler monkeys makes their calls loud. It's not just big but also shaped in a 'U'. This makes their howls sound unique and louder than most other animals.
When a howler monkey lets out a loud noise, the big hyoid bone helps. It makes the sound louder and more profound. This is how they can chat with each other in the forest.

Long-Distance Chat:

Howler monkeys use loud sounds to talk if they are far from each other. Their low howls can pass through the trees, so they don't have to see each other to speak. They use their sounds to mark where they live and tell other troops where they are.
Howler monkeys make more than one type of noise. They make roars, grunts, and barks. Each sound means something, from "I'm the boss!" to "Look out!"

Survival Tricks:

The big hyoid bone of howler monkeys shows how they changed to live in trees. They need loud sounds to stay safe in the thick forest. Their calls also tell other animals to stay away from danger.

Conservation:

To help howler monkeys, we need to keep their homes safe. They are at risk because their homes are being lost. If we stop their homes from being lost, we help keep these unique monkeys safe.
Howler monkeys have particular parts that help them make big sounds. Their howls fill the forests with sound. We must keep their homes safe so their calls can still be heard in the Americas.