The Indiscreet Charm of the Howler Monkey: “Can you hear me now?”

“Each [howler monkey] has an outsized hyoid bone, at the base of its tongue, allowing it to brace tongue against larynx in ways not possible to other animals. In human beings, the more discreet equivalent of this bone makes speech possible. In howler monkeys, it facilitates an excruciatingly loud noise, which is used by male and female alike to announce their territory. These are, according to the Smithsonian Institute (you see, I’m checking everything now), the loudest animals in the world.How loud? You can hear them five kilometres away, through dense tropical foliage. On a modern, wind-swept university campus, you can probably hear them even farther.” — David Warren