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 ...

When it comes to sex, you can’t have it all. Male howler monkeys are famed for their deep, powerful roars, which are among the loudest noises made by terrestrial animals, and may help them compete ...

The “big truck, small man” phenomenon is also seen in the animal kingdom. The loudest howler monkeys were found to have the smallest packages. Hyoid bone size, which is responsible for vocalizations, ...

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. Venezuelan Red Howler (Alouatta seniculus). They inhabit rainforests and mountain forests of Central and South America. The ...

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 ...