This Red-Faced Monkey Isn't Blushing

From pygmy marmosets to lowland gorillas, the world of primates encompasses a diverse and colorful range of creatures.

There's no better example of this than the bald-headed uakari (Cacajao calvus), a monkey hailing from the Amazon rain forest that boasts a bald crown punctuated by bright, crimson-hued skin. The perpetual blush is caused by a lack of skin pigment and a glut of capillaries beneath the skin.

Healthy Hue of Red

What's especially interesting is that this striking skin coloration is more than just a surface-level aesthetic trait. The vibrancy and richness of the red is also a visual indicator of the overall well-being of a monkey, and specifically for monkeys that have contracted malaria.

According to Arkive, "monkeys who have contracted the disease are noticeably paler and are not chosen as sexual partners as they do not have the desired natural immunity to malaria."

While the bald, red head is usually the first thing people notice, the bald uakari is also distinguished for its long-haired, bushy coat and its remarkably short tail (see above) — a trait that is relatively uncommon among New World primates. the monkey also has an exceptionally low percentage of body fat, which contributes to its unusual, gaunt facial structure.

As fascinating as these primates are, the IUCN currently lists the bald-headed uakari as a "vulnerable" species due to a 30 percent decline in population over the past three decades. The cause of this trend is troubling, but not at all surprising when compared to the conservation struggles of many other Amazonian flora and fauna.

Like many other New World monkeys, habitat loss and hunting are the two biggest threats to the bald-headed uakari. Uakari monkeys spend most of their lives foraging, eating, socializing and sleeping within the dense canopies of the Amazon's várzea forests — seasonal floodplain woodlands that are inundated with water for much of the year. That means they don't spend much time on the forest floor, except for brief visits during the dry season.

Because of their specialized arboreal habitats and foraging practices, uakaris are especially vulnerable to human encroachment and deforestation.

The outlook for this species may sound bleak, but there is hope in new research.

The uakaris' closest relatives, saki monkeys, have shown a remarkable "tolerance and adaptability" to disturbance of their similar arboreal habitats, according to the IUCN.

While the preferred conservation measure is to preserve the uakari habitat, the possibility that this animal might be able to withstand such man-made ecological pressures has many scientists and animal lovers crossing their fingers.