The proboscis monkey doesn't get enough attention, in my opinion, so I'm here to spread some long-nosed love!
I recently heard some of the noises that male proboscis monkeys make, and boy, I was NOT prepared. Have you heard them? Sometimes they sound like they're saying "Hey! Hey!", and sometimes they sound like they're honking or roaring. It's quite….something.
Last year, Dr. Katharine Balolia, Senior Lecturer in Biological Anthropology at Australian National University, led a team of researchers who set out to understand the hows and the whys of the giant nose of the male proboscis monkey and how it might be connected to the noises they make—through investigating both the size and shape of the bony nasal cavity that sits right behind the monkey's fleshy nose.
After examining the size and shape of 33 adult proboscis monkey skulls, the researchers found that the nasal cavities of male proboscis monkeys are shaped differently than those in females—the male cavities are lower and longer than the female ones. They conclude that, indeed, there is a direct connection between the male "enhanced nasal structures"—which include both their large fleshy noses as well as the nasal cavities of their skulls—the sounds they make, and their status in a community. That is, male proboscis monkey noses evolved in such a way that allowed for "more effective honks and nasal roars," which signal their fitness to the female monkeys in their group. In The Conversation, the researchers explain:
This [long and low shape] allows males to build up resonance (sound vibration) in their nasal cavities, allowing them to emit deeper and louder calls through their noses . . .
Our findings help to explain how these noses function as visual and acoustic signals of health and status. They also add to a growing body of evidence that shows researchers can use close examinations of skulls to glean information about primate social behaviour.
If you want to hear (and see) those male proboscis monkeys doing their thing, check out the videos I've linked, below! And if you want a treasure trove of proboscis monkey content, check out this YouTube channel!
Previously:
• A visit to Iwatayama Monkey Park in Kyoto Japan
• When you could buy a monkey from the Sears mail-order catalog
• A cute / alarming experience at the Iwatayama Monkey Park
• Adorable monkey looks like cryptid from afar
• Baby spider monkey in a onesie discovered in a Rolls Royce during a DUI stop
