Baby, I’m howlin’ for you. Male howler monkeys make deep and boisterous calls to attract mates, but the deepest-pitched songs may come at cost: the size of their testicles. A new study in the journal ...

Howler monkeys are named for their impressive howling roars. Their vocal abilities are linked to long vocal folds and a hyoid bone uniquely adapted to resonate sound, making males seem bigger than ...

A black howler monkey vocal chorus is seen at the Biological Field Station Corrientes, Argentina in this handout image released to Reuters on October 21, 2015. REUTERS/Mariana Rano/Handout via Reuters ...

SALT LAKE CITY, Oct. 22, 2015 - Across the animal kingdom, males hoot and holler to attract females and ward off competing suitors. Now, a new study finds that male howler monkeys with deeper calls ...

In a recent study, scientists report that howler monkeys in Costa Rica make longer calls in forest interiors and near naturally occurring forest edges, such as those along rivers, than near ...

WASHINGTON, Oct 22 (Reuters) - The howler monkeys whose guttural calls reverberate through Central and South American rainforests possess a secret that the males of the species may prefer to be left ...