By Stephen Beech via SWNS
The proboscis monkey grew his famously big nose so he could get more sex, according to a new study.
The male of the endangered species’ droopy conk evolved to attract mates, say scientists.
Researchers from The Australian National University (ANU) came up with the world-first explanation for why male proboscis monkeys have larger and “enhanced” nasal structures.
When the team examined the bony nasal cavity inside the skulls of the primates, they found their large noses offer several “major benefits”- especially when it comes to attracting potential female partners.
Living on the island of Borneo, proboscis monkeys have been branded one of the world’s “ugliest” creatures due to their large and unusual-looking noses.
Study lead author Dr. Katharine Balolia and former ANU masters student Pippa Fitzgerald used 3D scans of proboscis monkeys’ skulls found in museum collections to take size and shape measurements of the internal structure of the primates’ bony nasal cavity.
Their findings, published in the journal Scientific Reports, show the shape of the bony structure of the nasal cavity of male proboscis monkeys evolved to allow them to emit louder and deeper calls such as “honks” and “nasal roars”.
Dr. Balolia said: “We wanted to understand why male proboscis monkeys’ noses are so big, and whether their nasal cavities have a distinctive shape.
“We found that males have much bigger nasal cavities than female monkeys, and their nasal cavities also have a different shape compared to females.
“Being able to emit louder and deeper calls thanks to a longer and larger nasal cavity helps male monkeys to assert their health and dominance.
“This helps the male monkeys attract females and ward off other males.
“The more females a male can attract, the more it allows him to father more offspring.
“So having a large nose and being able to more easily emit honks and nasal roars due to a uniquely shaped nasal cavity really helps males show off their quality and status to prospective female partners.”
Dr. Balolia believes the jungle-like environment in which the endangered primates live could explain why their noses evolved to become so big.
She said: “Proboscis monkeys live in coastal mangroves and forested environments and often can’t see each other through the trees.
“So loud, nasalized calls are important to communicate with each other, especially amongst males.
“The fleshy nose tissue likely got bigger over time as it enhanced their ability to let out nasal honks and roars.
“Proboscis monkeys rigidly straighten their noses when giving these calls.
“Females may have then started to find large noses visually attractive for selecting a mate as it was an honest signal of health and dominance.”
The research team also found the bony nasal cavity opening of male proboscis monkeys – where the fleshy nasal soft tissue attaches – gets bigger with age, which is consistent with older males having larger noses.”
Dr. Balolia added: “This coincides with when they achieve dominance status among other male monkeys, allowing them to scare off other males and attract a lot of females who are ready to breed,”
