Dunn’s team analyzed the biological “budget” of these primates and found a direct negative correlation: males with large ...

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 ...

Reader John Honeyman shared this amazing photo of a howler monkey spotted in Santa Teresa, a beautiful town on Costa Rica’s Nicoya Peninsula. Santa Teresa is known for its stunning beaches, but it’s ...

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 ...