The monkeys' "ultra-yodels" had frequency leaps that were five times larger than human frequency changes, often exceeding ...

Howler monkeys are a New World primate that have specialized ... distributing the available food resource by traversing the forest canopy. They are a social species, with caring interactions ...

They can use this tail as an extra arm to grip or even hang from branches—no Old World monkeys have such a tail. A gripping tail is particularly helpful to howler monkeys because they rarely ...

According to the fifth census of Mantled Howler Monkeys, Alouatta palliata, on Barro Colorado Island in Panama, monkey numbers have changed little since the late 1970s. Disclaimer: AAAS and ...