Howler monkeys are named and known for the loud, guttural howls that they routinely use at the beginning and end of the day. They are the loudest animal in the New World and while their howl is not a piercing sound, it can travel for three miles through dense forest.

Male howler monkeys use their big voices to defend their turf. Howls by one troop are answered by other males within earshot. Every-one starts and ends the day by checking out where their nearest competitors are. In this way, they protect the food in their territory. It’s an important job because their diet is made up mostly of leaves—not a particularly nutritious food. Finding young, nutritious leaves is a priority. Fruit and flowers are also valued so it’s crucial that the troop stakes its claim on these treasures when they are found.

Despite the volume of their howl, it’s disorienting to try to find a troop of loud howler monkeys in the wild. They hang out in the treetops where younger, greener leaves are abundant. However, if you do find yourself in the rainforest and it seems that an unusually large amount of fruit is falling from above or a fine spray of urine rains down on your head, you will know you are close!