Red Butt Monkeys: What Monkey Has A Red Bottom?

Red Butt Monkeys - What Monkey Has A Red Bottom

Have you ever gone on a zoo trip and come across some monkeys with red butts? If you didn’t know about these primates, that might have come as a surprise. 

Monkeys with red or dark pink bottoms include baboons, chimpanzees, rhesus macaques, mandrils, Japanese macaques, and Celebes crested macaques.

For monkeys, color plays a vital role in their lives. They use color as a means of communicating non-verbally with other monkeys. A colorful bottom is one of the ways they have these non-verbal conversations.

Read on to know more about these red butt monkeys.

What monkey has a red bottom?


Close Up Baboon with Visible Red-Pink Butt

Baboons are one of the old-world most giant monkeys. Five baboon species live in Africa and Arabia–the olive, the yellow, the chacma, the guinea, and the hamadryas.

Four of these species can be found scattered across various habitats in the savannas (olive, chacma, yellow, and guinea).

The last one lives in semi-arid habitats, tropical rainforests, and hills along the red sea (the hamadryas/sacred baboons).

The swollen red bottom is more prominent and spectacular in females, especially in the heat season. The female baboon’s butt swells to about 4-6.5 inches (10 and 16.5 centimeters), and after ovulation, it goes back to its standard size.

During their heat periods, the female baboons’ butts become bright red and swollen, always catching the male baboons’ attention, and making them desire the females more.

The male baboons mate with non-nursing females and those that have experienced more sexual cycles since their most recent pregnancy. 


Group of Chimpanzees at the River Bank

Chimpanzees can also be called “Chimps”. They are not precisely monkeys because they do not have tails. Different chimps have different sizes and shapes of buttock swellings.

Like in many female monkeys, a red and swollen bottom indicates an ovulating and fertile female looking for a mating partner–this is a non-verbal way for the female chimp to communicate her sexual wants to the male chimp anytime she’s on heat.

In the same way we humans are good at recognizing faces, the chimps are good at recognizing rear ends (they can remember faces, too), and this further proves that buttocks are pretty outstanding in a chimp’s world.

They can realize butts when they see one because they know that when their females get red and swollen butts, it means it is time for mating.1

A chimp also knows who a relative, friend, or enemy is and how healthy they are.


Mandril with Pink, Red and Blue Bum

People often mistake mandrils for baboons because they are similar physically, except that mandrils have a stub tail while a baboon is prehensile.

Mandrils are a different species of monkeys that also live in Africa. The dominant male mandrils have a more colored backside than the females, who get a swollen red butt when ready to mate. 

The high-ranking males also have more colorful butts than other males in the troop because when they win a fight to become leaders, their testosterone level increases, which will bring about an intense color change. These colorful males are the most sought-after by female baboons.

Japanese Macaques

Two Japanese Macaques on Ground

The Japanese macaque is also known as Snow Monkey, and they stand out because of their red faces and equally red butt. 

Similar to many other monkeys on this list, the females have redder butts than the males. These red bottoms make them sexually attractive.

Rhesus Macaques

Mother and Baby Rhesus Macaques Monkeys

The Rhesus macaque, also known as Mavava mulatta, is an old-world monkey that often stays on land.

Both male and female Rhesus macaques have red behinds and red coloration on their face and genitalia.

Generally, red skin is sexually attractive to all macaques. The female macaque love males with redder butts.

Experts suggest that a female rhesus macaque might have a greater chance of finding a mating partner when her butt is swollen and red.

Celebes Crested Macaques

Close Up View of Celebes Crested Macaque in the Jungle

The Celebes crested macaque is also known as the Crested black Macaque. The female uses its outrageously swollen rear end to indicate that it’s ready for mating.

These monkeys have the most impressive and reddest butt in the primate world. The female butt swells enormously and becomes a very bright red when in season, but on regular days the male Celebes have a much redder butt.

Frequently Asked Questions

Why do monkeys have red bums?

Red butts in female monkeys are a way of letting the makes know that it is mating time. The male Mandrils’ multicolored bottoms signify their social status in the troop. This distinct feature in monkeys also serves other purposes.

Why is a baboon’s butt red?

Baboons and other primates announce their fertility by employing sexual red-colored swellings. When the female baboons ovulate, their butts swell, which signals that they are fertile, although not all male baboons are intrigued by a red bottom.

Is a baboon a monkey or an ape?

Most people will see an ape and call it a monkey and vice versa, but do you know that these two are not the same? Baboons are not apes because they have tails (apes do not have). Technically, baboons are monkeys, even if they can be categorized separately from other monkeys due to a few differences.

What monkey has a colorful bottom?

The Mandril has the most colorful bottom, and its face is as colorful as its butts. This bright facial and buttocks coloration is present in both sexes but much more vibrant in high-ranking males.

Why do chimpanzees have big red bottoms?

In a real sense, chimpanzees do not have big butts. Instead, their female chimps have red and swollen genitalia. This swelling occurs during their fertile phase, and do they make chimps love this sight? You bet!

Is there a monkey with a blue bottom?

Lesula is a monkey newly discovered in the Democratic Republic of Congo and found exclusively in Sub-Sahara Africa. Its buttocks and perineum and scrotum are a bright blue-white color. The male Mandrils also have a multicolored bum with a majorly blue color.

Why are mandrils butts blue?

The butt tissue of the mandrils is arranged so that blue photons are reflected, and the red and every photon is then absorbed. The blue light gets out and is more visible to our eyes. Because we see the color blue reflected, we say the mandril’s butt is blue.

What monkey has a pink bum?

Monkeys like the Sulawesi crested macaque have a heart-shaped pink bottom.

Why do monkeys have pink bottoms?

Monkeys show they’re fertile by showing off sexual swellings. The ovarian hormones will induce the skin around the genitals as the monkeys approach ovulation, and this will cause that area to take on a pink color. This effect is known as tumescence.

Final Thoughts on Red But Monkeys

Many monkey species have red butts, which not only attract both genders to themselves but also indicate the time of ovulation, declaration of attraction, and social status in the group and send a warning to males like the baboons who want to mate with ovulating females.

References & Notes

Facts Sources:
  1. Brulliard K., (2016). Chimpanzees recognize rear ends like people recognize faces. Washington Post.