Sound up! If you’re brave! Our howler monkey pair, Carlito and Eva, like to demonstrate exactly why they’re called howler monkeys. It’s not unusual for both male and female howler monkeys to howl together. It’s thought that this both establishes their territory and strengthens their mate bond. Howler monkeys can be heard up to 3 miles away, so chances are if you live near the Zoo, you can hear these two singing love songs to each other! | Potawatomi Zoo