You may think of yaks as very hairy cattle — which is what they're called in China — but yaks have a long history with humans in the highlands of Asia.

Their hardiness combined with simple diets of grass have made them popular pack animals, companions and sources of food and fabric for centuries now. And their popularity as livestock is spreading around the world as people look for alternatives to traditional livestock like cows. So it's worth learning a bit more about the yak and its place in history.

1. There are 2 different yak species

A woolly black yak stands in front of mountains
Wild yaks grow to be great quite large. (Photo: aleksander hunta/Shutterstock)

Currently, we recognize the wild yak (Bos mutus) and the domestic yak (Bos grunniens). They, like a number of other cattle species, likely descended from aurochs, an extinct species of large cattle. Yaks probably split from aurochs between 1 and 5 million years ago.

The key difference between wild and domestic yaks is size. Domesticated yaks are normally smaller than wild yaks, with males weighing 600 to 1,100 pounds (300 to 500 kilograms) and females weighing 400-600 pounds. A male wild yak can weigh more than 2,000 pounds. For comparison, an average male cow tops out at around 1,500 pounds.

2. Wild yaks were domesticated around 5,000 years ago

A yak with yarn around its horn
Yaks have a long history in Asia. (Photo: Arijeet Bannerjee/Shutterstock)

The Qiang people lived along the Tibetan Plateau borderlands, near Qinghai Lake, and they are considered to be responsible for the domestication of the yak. Records from the Han dynasty indicate that the Qiang had a "Yak state" from 221 B.C. to 220 A.D. This "state" was a trade network that predating the Silk Road. Genetic testing supports this domestication time frame.

The domesticated yak is a useful animal. It works as a pack animal, and its body can provide meat that's leaner than cow beef, clothing and fabric for shelters and ropes.

3. Yak milk may be a superfood

A bowl of yak butter tea
Yak butter tea is a high-calorie beverage that lots of communities enjoy. (Photo: D. Pimborough/Shutterstock)

Few parts of a yak are wasted in the highlands of Asia, and this is particularly true of its milk. In 2008, the China Nutrition Society declared yak milk to contain more amino acids, calcium and vitamin A than cow milk. The society is research institute backed by the Ministry of Health.

Yak butter is the key ingredient in yak butter tea. Made using black tea and salt, the tea is topped off with a helping of butter to add some healthy fats and calories. Where butter is unavailable — or for those who would rather sell the butter outright — you can just add the milk.

4. Domestic yaks are thriving while wild yaks are dying out

Two yaks walk along a mountain path
Domesticated yaks have a sizable population. (Photo: Guillaume Baviere/Wikimedia Commons)

The wild yak, once widespread in the Tibetan Plateau, is considered threatened on the International Union for Conservation of Nature's Red List, with only an estimated 7,500 to 10,000 mature individuals left in the wild.

Domesticated yaks, however, are prevalent over much of the world. An estimated 14 to 15 million live in the highlands of Asia.

5. People race yaks at festivals

It's no mutton busting, but it is a time-honored tradition among some communities to race yaks, as you can see in this video. The races run from the unruly and local to large-scale events, like in the video above, but even those are still a little unruly.

6. Yak ranching is on the rise in North America

Group of yaks in a field
Yaks are located in various regions around the world. (Photo: Perfect Lazybones/Shutterstock)

Yaks don't only appear in Asia. Speaking to The Denver Post, the president of the International Yak Association estimates that there are 5,000 registered yaks in North America, but says there is probably many more yak out there.

"They only eat about a third of what a cow eats and can forage for food without damaging the environment," yak rancher Tom Worrell told The New York Times in 2003. "They have small hooves and are nimble, so they can move over rough mountainous terrain. They don't need much attention. Unlike cows, you don't have to get up in the middle of the night and calve them. They are pretty disease-resistant, so they don't need any hormones or antibiotics. And unlike bison, they are docile and easy to maintain."

7. Yak fiber is the new cashmere

Beanies made of yak wool
Yak fiber can be used in a variety of products. (Photo: Kondoruk/Shutterstock)

Cashmere, in case you didn't know, comes from Mongolian goat hair. The goats, however, are hard on the environment. Yaks, however, are not, and their fiber is as soft and as warm as cashmere, according to boosters of the fiber. While yak fiber has been used for thousands of years in Asia, getting it to clothing stores in the West has been more challenging.

"These hardy little beasts have to live through considerable temperatures and their fiber is genuinely luxurious," Robin Deas, a textile technician, told CNN in 2018. "The thing is being able to promote it in a way that gives the luxuriousness of what it is."