Turkey vultures have the ultimate self-defense technique: projectile vomiting

Plus other weird things we learned this week.
Turkey vulture sitting on a rock
Turkey vulture. DepositPhotos

What’s the weirdest thing you learned this week? Well, whatever it is, we promise you’ll have an even weirder answer if you listen to PopSci’s hit podcastThe Weirdest Thing I Learned This Week hits AppleSpotifyYouTube, and everywhere else you listen to podcasts every-other Wednesday morning. It’s your new favorite source for the strangest science-adjacent facts, figures, and Wikipedia spirals the editors of Popular Science can muster. If you like the stories in this post, we guarantee you’ll love the show.

FACT: Curly hair may have evolved to keep our heads cool

By Rachel Feltman

As a certified Curly Girl, I’ve always been fascinated by the different shapes human hair can take. But for most of modern history, science has woefully neglected the study of curly and tightly-coiled hair. Thankfully that’s starting to change, due in large part to the curiosity-driven research and advocacy of Dr. Tina Lasisi. You can read more about Lasisi and her work on the morphology and evolution of human hair here, in an awesome article by PopSci alum Hannah Seo

On this week’s episode of Weirdest Thing, I dig into the findings of one of Lasisi’s most intriguing studies. In 2021, she and her colleagues were able to demonstrate that curls help keep our heads cool. Humans evolved to rely on thermoregulation from sweat, which uses evaporative cooling. But our big ol’ brains are prone to overheating, so in a perfect world, we don’t want them getting hot enough to produce sweat in the first place. That’s likely why we kept the fur on our heads while losing almost all the rest of it, which makes us look pretty bizarre lined up with other mammals and even other apes. Hair can block the radiant heat of the sun, thereby preventing it from scorching up our scalps and cooking our noggins. 

Here’s the problem: While hair does physically block sunlight from hitting our heads, it also serves as insulation, trapping any heat that makes it through. 

Because tighter curls tend to correspond with areas with higher UV exposure, globally speaking, Lasisi and her colleagues decided to test whether coils and ringlets did a better job of keeping heads cool than straight hair. They tested this using a delightfully odd looking setup involving mannequins with glamorous wigs and power cords plugged into their eye sockets

Sure enough, they found that wavy hair kept heads cooler than straight hair, while tighter cools provided the greatest cooling effect at all. And having any kind of hair was better than being bald, in terms of the sun’s ability to sizzle the skin atop your skull. 

Lasisi and her colleagues think that curls create a sort of spongy effect, allowing air to circulate freely and keeping heat from getting trapped there. Listen to this week’s episode of The Weirdest Thing I Learned This Week to hear more interesting facts about the evolution of curls and coils.

FACT: Turkey Vultures projectile vomit in self defense

By Liz Clayton Fuller

Turkey Vultures are one of the heroes of the bird world. Often misunderstood, these incredible birds perform a service to society by eating carrion, the decaying flesh of dead animals. Carrion can carry (see what I did there) all kinds of toxins and diseases like anthrax, tuberculosis, and even rabies. Incredibly, Turkey Vultures can ingest all of the aforementioned contaminants unharmed because their stomachs are so highly acidic! The acidity of their stomachs makes their projectile vomiting strategy particularly effective. While consuming their carrion prey they stay nice and clean by having bald heads with no feathers and huge nostrils so that no bits of carrion get stuck to them. They also engage in a practice called “urohidrosis” which is where an animal urinates on itself in order to cool down when it gets hot out, so Turkey Vultures have certainly earned their reputation for being a little nasty—but still amazing.

So Turkey Vultures perform this incredible service to humanity by cleaning up carrion, but how do they find the carrion to take care of? Turkey Vultures have the largest and most powerful olfactory system in the bird world which helps them find their (already deceased) prey. Their sense of smell can lead them to carcasses miles away and in fact many other Vultures rely on Turkey Vultures to locate carrion and then they follow them to it! As for what kind of carrion is on the menu, they prefer freshly dead meat. It is a common misconception that Turkey Vultures stalk and kill their prey, but they only arrive after their prey is deceased. Other than the common denominator of being freshly dead, Turkey Vultures aren’t picky at all. In Tennessee alone I’ve seen them on the clean up crew of Armadillos, Skunks, Cow, Deer, Groundhogs, and more. So next time you see a Turkey Vulture soaring by, tell them thank you for being nature’s clean up crew!

Fact: Renegade Zambian astronauts tried to beat Americans to the moon

By Purbita Saha

In 1964 the world was buzzing about the space race between the US and the Soviet Union. But a feature in Time magazine brought forth a new contender: Zambia, a southern African country that had recently won independence from the British. In the article, a science teacher named Edward Makuka Nkoloso shared that he was training a team of 12 astronauts to catapult his nation to the surface of the moon. No, they weren’t literally building a space catapult—they had a claustrophobic barrel-shaped rocket—but the candidates were learning to walk on their hands because that’s how Nkoloso thought they would have to navigate inhospitable lunar terrain. Ultimately, the teacher settled on a crew of a teenage girl, a missionary, two cats, and his own dog, Cyclops. But without any funding, Nkoloso’s dream to send his country folk beyond Earth’s orbit fizzled into legend. No one could ever confirm if his endeavor was genuine or an attention-grabbing stunt—a 2014 short film called The Afronauts reimagines it as pure fiction.

Maybe Nkoloso would be proud of his region’s emerging importance in astronomy today. From the MeerKAT radio array to the Africa Millimeter Telescope, multinational teams of scientists are finding never-before-seen wonders in the stars, all thanks to the clear skies of southern Africa. If nothing else, the proud Zambian who was interviewed by Time more than 60 years ago had a vision for the future.