Why do some monkeys have blue testicles? | Weird animal facts

Good-looking eggs are good-looking eggs.

Written by Su Chengyu

These are the best looking balls in the worldCredit: Larry Petterborg

This entry, shortlisted for the 2021 Comedy Wildlife Photography Awards, shows a vervet monkey looking at its blue testicles, as if to say: Wow! How can there be such beautiful testicles in the world?

In fact, it’s not just the Vervet monkeys, there are several other species of monkeys that have blue eggs:

Erythrocebus patas

Image source: deviantart.com

Mandrillus sphinx: Not only are their balls blue, but their butts are also colorful

Image source: National Geographic

Lomami monkey (Cercopithecus lomamiensis)

Image source: futurity

They all have blue eggs, but the vervet monkey's are particularly eye-catching, the bluest and most obvious.

Why is it so blue?

Because the bluer, the more melancholy

We all know that male peacocks spread their tails to show their unparalleled sexual charm to attract the attention of female peacocks. The more gorgeous the tail is, the easier it is to defeat potential rivals, thereby gaining the recognition of females and spreading their ancestral DNA.

Similarly, the bluer the monkey's eggs, the more advantages they have in sexual selection. Scientists have found that the deeper the blue of the East African vervet monkey's eggs, the higher its social status in the group, and the higher the social status, the more attractive it is to females. In addition, the bluer the eggs, the more likely they are to bully young monkeys. The more aggressive the monkey, the more male hormones it secretes.

It is said that power is the best aphrodisiac, and this is also true for monkeys.

The data corresponding to different testicle colors of monkeys, such as height, weight, and testicle volume; the aggressiveness of different testicle colors, the higher the score, the stronger the aggressiveness丨Source: Literature 1

You will find that it is easy for photographers to capture the scene of them with their legs spread out and their heads down looking at their eggs in thought.

Image credit: Mary Anning

Image credit: Mary Anning

Image credit: Mary Anning

One has to wonder if they are also confused about their own blue eggs. Why! ? Why are they so blue!

Of course, this indecent posture, spreading your legs to show your balls, is more like a way of showing off: Look, my balls are so beautiful and manly.

Image credit: Mary Anning

Why is it so blue?

Mammals have only two pigments in their fur: one pigment makes the hair black or brown, and the other pigment makes the hair yellow or orange. Albinism is caused by the lack of pigment. In theory, if it is just like a paint palette, no matter how you mix the colors, you can't get blue.

But nature has created something called structural color, which is the color produced by the scattering, interference or diffraction of light when light is incident on an object with a spatial period similar to the wavelength. For example, the colorful soap bubbles you see in the sun are a manifestation of structural color.

The blue color on the skin of monkeys' testicles is also a structural color. According to a 2004 study, monkeys with blue testicles have unusually neatly organized collagen fibers in their skin. Changes in the structure of these collagen fibers, even by a millionth of an inch in size or distance, can produce different colors. Blue is one of those structures.

So, that’s how monkeys get their blue eggs.

Will the balls always be this blue?

Just like human hair turns gray and white as we age, the color of our testicles also changes over time.

For red monkeys, their color is sea blue when they are young and blue-green when they are adults.

For vervet monkeys, their colour is dull blue when they are young, bright blue when they reach puberty, and white when they get older.

But if it is a human testicle, it is best not to expect it to turn blue, also known as blue balls. "Blue Balls" is a vulgar term that originated around 1916, meaning that when a man cannot release for too long, it is professionally called: epididymal hypertension. At that time, the testicles may have a hint of blue, which is the blue of venous blood. Of course, it will not be as blue as monkeys. If it is that blue, it is probably...

References

[1] Primate color predicts social status and aggressive outcome - ScienceDirect

[2] http://www.oaklandzoo.org/Vervet_Green_Monkey.php

[3] Mary Anning's Revenge: 14 Days of Genitals, Day 5: Blue Balls to the extreme (maryanningsrevenge.com)