# Yak (*Bos mutus*)

Yaks are large, shaggy animals with long horns that live in the mountains. They are strong and can carry heavy loads. Yaks have thick fur to keep them warm in cold places.

- **Category:** [Mammals](https://www.snappit.app/explore/categories/mammal)
- **Rarity:** Rare
- **Danger:** 3/5 · Moderate
- **Habitat:** Mountain regions
- **Also known as:** Domestic Yak, Wild Yak

![Yak](https://res.cloudinary.com/drieglelr/image/upload/v1771424591/objects/6521.jpg)

## Appearance

The Yak has a massive, muscular body covered in long, shaggy fur that can be black, brown, or grayish. It features a distinctive hump on its shoulders and short, sturdy legs with small, hard hooves. Its prominent, curved horns sweep outwards and then upwards, making it easily recognizable.

## Taxonomy

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Family:** Bovidae
- **Genus:** Bos

## Yak, up close

The yak is a large, long-haired wild ox of the Tibetan Plateau and the Himalaya, built for cold, thin air at 3,000–5,500 m. The wild yak (Bos mutus) is a Vulnerable species with roughly 15,000–20,000 left. About 16 million domestic yaks (Bos grunniens), tamed from wild yaks around 7,300 years ago, give herders milk, butter, wool, transport and dung for fuel.

Also called: Dri (Tibetan for a female yak), Yag (Tibetan for a yak bull), “Boat of the plateau” (nickname for pack yaks).

A coat that works at −40 °C, lungs twice as heavy as a cow’s and a grunt instead of a moo. Spin it, tap it, then test yourself.

### Special abilities

- **Thin-Air Engine** (≈2× lung weight of local cattle): High on the plateau, every breath carries far less oxygen. Big lungs, a big heart and relaxed lung blood vessels let yaks cope. [2][7][8][10][11]
  - Air at 3,500 m has about 35% less oxygen than at sea level, and at 5,000 m about half.
  - Yak lungs weighed 3.7 kg in one study, about twice the 1.8 kg of local cattle.
  - In cows taken high up, the lung blood vessels clamp down and blood pressure in the lungs rises dangerously. In yaks this reaction has almost disappeared.
  - Yak haemoglobin, the oxygen carrier in blood, holds on to oxygen more tightly than cow haemoglobin. The yak genome shows many genes linked to low oxygen.
  - Lung weight: Yak 3.7 kg; Yak × cattle hybrid 2.5 kg; Local cattle 1.8 kg
- **Deep-Freeze Coat** (−40 °C still grazing normally): Three layers of hair, thick skin and almost no sweating keep the heat in. Yaks feed and move normally at −30 to −40 °C. [2][12]
  - Thick outer hairs (70–90 µm across) sit over a soft winter down only 16–20 µm thin.
  - No case of frostbite has been recorded in yaks, even on their ears or tails.
  - In the cold season a yak’s heart beats about 51 times a minute, against 78 in the warm season, and its body runs on less energy.
  - The flip side: yaks struggle in heat. Above 13 °C they breathe faster, and at about 20 °C they stop grazing.
  - How thick is each hair?: Coarse outer hair 70–90 µm; Winter down 16–20 µm
- **Summer Moult** (May–June when the winter wool comes off): Each autumn a yak grows a thick winter coat. In early summer the woolly down loosens and falls out in clumps. [5][3][12]
  - Hair and down grow before winter and are shed in late spring or early summer if nobody harvests them.
  - Herders shear their yaks or comb out the soft down once a year, in May–June. Combing gets more down.
  - Since the 1970s, the textile industry has spun yak down into soft yarn for clothes.
- **Snow Eater** (>20× more likely near snow (females vs males)): In winter, when streams freeze solid, wild yaks are thought to eat snow for water. [1][13]
  - Early travellers on the plateau already reported wild yaks eating snow.
  - In winter surveys in Hoh Xil (Kekexili), Tibet, female wild yaks were more than 20 times as likely as males to be found within 200 m of snow patches.
  - With streams and lakes frozen, snow may be their main water. Females and young live in big herds, about 30 on average; bulls roam in twos and threes.
- **Snow Plough** (28–38 kg grass eaten in 10 hours in summer): When snow and ice cover the pasture, yaks break through with their hooves and heads to reach the old grass beneath. [2][12]
  - Herders even send yaks ahead to stamp tracks through deep snow for people, a sort of “biological snow plough”.
  - In winter there is so little grass that a yak may eat 13 kg or less in 10 hours, against 28–38 kg in summer.
  - Over a long winter yaks can lose 25–30% of their body weight, then put it back on in summer.
  - Grass eaten in 10 hours: Summer 28–38 kg; Winter ≤13 kg
- **Grunt Talk** (grunniens Latin for “grunting”): Yaks do not moo. They grunt, which gave the domestic yak its scientific name, Bos grunniens: the grunting ox. [14][1][6][15]
  - The wild yak was named Bos mutus, “mute ox”, by a Russian explorer who thought it was silent. Scientists call that a poor name: wild yaks are quite noisy.
  - In the breeding season wild yaks grunt, bellow, squeak and cry.
  - A threatened wild herd may snort loudly before running off or charging.
- **Horn Ring** (100+ herd size that rarely loses animals to predators): Faced with wolves, a herd bunches into a tight group with the calves in the middle and the horns facing out. [2][1][16]
  - Herds of 100 or more yaks rarely lose animals to predators. Bulls have reportedly killed wolves with their horns.
  - Wolves and brown bears are the main wild predators. Snow leopards take domestic yaks in some areas.
  - In the breeding season, rival bulls stand side-on 3–6 m apart to show off their size, and may then spar for up to 15 minutes.
- **Pack Power** (60–80 kg load, 20–30 km a day): Domestic yaks are the “boat of the plateau”: steady pack animals that carry loads over high passes and snowy ground. [17][2]
  - A normal pack load is 60–80 kg, carried 20–30 km a day. One test team of steers carried 75 kg for 30 km in 6.2 hours, about 4.8 km/h.
  - The heaviest load on record is 300 kg, at 4,100 m in Qinghai: 82% of that yak’s own weight.
  - Pack steers can cross terrain as high as 7,200 m and can work for 2–3 days without food or water.
  - Pack loads: Record load 300 kg; Normal load 60–80 kg

### Body parts

- **Horns** (up to 99 cm a wild bull’s horn, along the curve) [1][2]
  - Both bulls and cows grow horns. They sweep out sideways, then curve upwards.
  - Measured along the outside curve, wild bulls’ horns are 47.5–99 cm long and cows’ 37–64.5 cm.
  - Yaks use them to defend themselves, especially against wolves, and bulls clash horns over mates.
- **Hump** (14 pairs of ribs (most cattle: 13)) [1][2]
  - The shoulder hump is not a fat store. It is built on extra-long spines that stick up from the backbone.
  - Yaks have 14 pairs of ribs, one more than other cattle, which gives them a big chest for big lungs.
- **Skirt** (up to 70 cm long hair hanging from the flanks) [1][3][4]
  - A fringe of very long, coarse hair hangs from the shoulders, flanks and belly, almost to the ground.
  - Herders shear or comb their yaks once a year, in May–June.
  - The coarse skirt hair is spun into ropes and woven into tents and bags.
- **Coat** (3 kinds of hair in one coat) [2][5][6]
  - The coat mixes thick outer hair, middle-sized hair and a soft woolly down. Down fibres are thinner than 25 µm.
  - In winter the share of soft down in the coat rises, like a yak putting on a thermal vest.
  - Wild yaks are jet black or dark brown, often with a silver-grey stripe along the back.
- **Lungs and heart** (3.7 kg yak lungs (local cattle: 1.8 kg)) [2][7][8]
  - At 5,000 m each breath holds about half the oxygen it would at sea level.
  - In one study, yak lungs weighed 3.7 kg and local cattle lungs 1.8 kg. Yak hearts weighed 1.3 kg, cattle hearts 0.87 kg.
  - A wide windpipe helps it move a lot of air, and the blood vessels in the lungs stay relaxed in thin air instead of squeezing tight as cows’ do.
- **Rumen** (≈72% of the stomach is rumen) [2][9]
  - Like a cow, a yak has a four-part stomach. The first part, the rumen, is a vat where microbes break down tough grass.
  - In one yak breed the rumen made up about 72% of the stomach, against about 52% in a cattle breed.
  - Yak rumen microbes make less methane gas than cattle microbes, which scientists think leaves more of the food’s energy for the yak.
- **Mouth** (2–3 cm short spring grass it can crop) [1][2]
  - Like all cattle, a yak has no top front teeth, just a hard pad. It has 32 teeth in all.
  - It wraps long grass with its rough tongue, but it can also nibble very short grass with its lips and teeth, as sheep do.
  - Yaks hardly sweat: tests found sweat only on the muzzle.
- **Ears and eyes** [2][1]
  - The ears are small and the body compact, which helps save heat. Yaks also have no loose dewlap under the neck.
  - Wild yaks have a keen sense of smell. Their sight and hearing are thought to be weaker.
  - Yaks are wary of wolves and people, and a startled herd quickly runs off.
- **Legs and hooves** (7,200 m terrain pack yaks can cross) [2]
  - Strong legs end in small, hard hooves with a narrow, sharp tip.
  - The hooves press deep prints into the ground, which helps a yak control its speed going downhill.
  - Yaks can swim across rapids. They plod on calmly instead of panicking.
  - Unlike other cattle, yaks roll on the ground, like horses.
- **Tail** [3][6][4]
  - The tail ends in a long, bushy tassel of hair. Herders harvest it every two years.
  - Yak tails have been used as fly whisks for nearly 2,000 years: the Roman poet Martial mentioned them.
  - In Tibetan areas, a yak tail is a symbol of wealth and good luck.

### Stats

| Stat | Value | Notes |
|---|---|---|
| Weight | ≈1,000 kg | a wild bull; wild cows about 350 kg; About 1.6× a dairy cow [1][21][23] |
| Domestic yak | 235–594 kg | domestic bulls in China; cows 188–314 kg [18] |
| Height | 1.5–2 m | a wild bull at the shoulder [21][1] |
| Horns | up to 99 cm | wild bull, along the outside curve [1] |
| Home altitude | 3,000–5,500 m | where wild yaks live [1] |
| Cold limit | −40 °C | still feeding and moving normally [2] |
| Skirt hair | up to 70 cm | long hair hanging from the flanks [1] |
| Lungs | 3.7 kg | against 1.8 kg in local cattle; About twice as heavy [2] |
| Pack load | 60–80 kg | carried 20–30 km a day [17] |
| Lifespan | 26 years | the oldest on record, in captivity [24] |

### Photos

- [Wild yaks behind a group of kiang (Tibetan wild asses) on a high plain](https://commons.wikimedia.org/wiki/File:%E8%97%8F%E9%87%8E%E9%A9%B4%E4%B8%8E%E9%87%8E%E7%89%A6%E7%89%9B%E3%80%90%E8%B7%AF%E4%BA%BA%E3%80%91_-_panoramio.jpg) (photo: leej1118bj, CC BY 3.0)
- [A wild yak drawn for the book Across Thibet (1891), after a photograph](https://commons.wikimedia.org/wiki/File:Across_Thibet_-_A_Wild_Yak.png) (photo: Gabriel Bonvalot (book); engraving after a photograph by Prince Henri d'Orléans, Public domain)
- [A black yak moulting its winter coat, Tibetan Plateau, July](https://commons.wikimedia.org/wiki/File:Molting_Yak_on_the_Tibetan_Plateau.jpg) (photo: Tenace10, CC BY-SA 4.0)
- [Pack yaks on the Everest Base Camp trail, Nepal](https://commons.wikimedia.org/wiki/File:Working_yaks_in_Everest_region.jpg) (photo: TT4FT, CC BY-SA 4.0)
- [A white domestic yak in Aba (Ngawa), Sichuan, China](https://commons.wikimedia.org/wiki/File:%E5%9B%9B%E5%B7%9D_%E9%98%BF%E5%9D%9D_%E7%99%BD%E7%89%A6%E7%89%9B_-_panoramio.jpg) (photo: Nyx Ning, CC BY-SA 3.0)
- [Piebald and dark yaks by Lake Manasarovar, with Mount Kailash behind, Tibet](https://commons.wikimedia.org/wiki/File:Yaks-Kailash-Manasarovar.jpg) (photo: Jean-Marie Hullot, CC BY-SA 4.0)
- [A mother yak and her calf at a zoo in Massachusetts, USA](https://commons.wikimedia.org/wiki/File:Yak_Mom_and_Calf_(20629938115).jpg) (photo: Eric Kilby, CC BY-SA 2.0)
- [Two yaks butting heads on the Tibetan Plateau](https://commons.wikimedia.org/wiki/File:Yak_fighting_on_the_Tibetan_Plateau.jpg) (photo: Tenace10, CC BY-SA 4.0)
- [A yak herd on summer pasture, Tibetan Plateau](https://commons.wikimedia.org/wiki/File:Yak_grazing_on_the_Tibetan_Plateau.jpg) (photo: Tenace10, CC BY-SA 4.0)

### Questions

- **Do yaks moo?** No. Yaks grunt, which is why the domestic yak is called Bos grunniens, the “grunting ox”. In the breeding season wild yaks also bellow, squeak and cry. [14][1][6]
- **Are yaks dangerous?** Yaks are big, strong and easily startled. Cows with newborn calves can attack, and wild bulls have charged people on remote roads. Never walk up to a yak, keep a wide distance, stay with an adult and let herders lead. [22][6][15]
- **How cold can a yak survive?** Yaks feed and move normally at −30 to −40 °C, and they graze where −42 °C has been recorded. Their three-layer coat, thick skin and lack of sweating keep heat in. No case of frostbite has been recorded. [2]
- **How high do yaks live?** Wild yaks live at about 3,000–5,500 m on the Tibetan Plateau, between the tree line and the glaciers. Domestic yaks are herded mostly at 3,000–5,000 m, and pack yaks can cross terrain at 7,200 m. [1][33][12][2]
- **What is the difference between a wild yak and a domestic yak?** Wild yaks (Bos mutus) are much bigger, bulls about 1,000 kg against 235–594 kg for domestic bulls, and are always dark with grey muzzle hairs. Domestic yaks (Bos grunniens) were tamed from wild yaks roughly 7,300 years ago and come in more colours. [1][18][6][35]
- **What are yaks used for?** Herders use yaks for milk (drunk in milk tea or made into butter and cheese), meat, wool and down, ropes and tents from the long hair, pack transport and dried dung, the main fuel on the treeless plateau. [4][11][17][5]
- **How many wild yaks are left?** Roughly 15,000–20,000, almost all in China. The wild yak is listed as Vulnerable on the IUCN Red List. Domestic yaks number about 16 million. [1][12][28]
- **Can yaks and cows breed?** Yes. Yak–cattle hybrids are called dzo in Tibetan areas and chauri in Nepal. The female hybrids can have calves, but the males are sterile. [21][14][25]

### Yak myths and facts

Tap Myth or Fact for each claim, then check the answer.

- "Yaks moo like cows." **Myth!** Yaks grunt. That is why the domestic yak’s scientific name is Bos grunniens, the “grunting ox”. [14][1]
- "Wild yaks are silent, which is why they are called Bos mutus, “mute ox”." **Myth!** The explorer who named them thought they were silent, but wild yaks are quite noisy. They grunt, and bulls bellow in the breeding season. [1][6]
- "Wild yaks eat snow when the water freezes." **Fact!** Early explorers saw it, and in Hoh Xil female wild yaks stay close to snow patches in winter, when streams are frozen. [1][13]
- "A yak’s hump is a store of fat, like a camel’s." **Myth!** The hump is built on extra-long spines that stick up from the backbone. Camels store fat in their humps; yaks don’t. [1]
- "Yaks have extra-thick blood, packed with extra haemoglobin." **Myth!** Studies summarised by the FAO found yak blood counts are not exceptional. The trick is that yak haemoglobin grips oxygen more tightly, and the lungs and heart are big. [2][10]
- "Yaks are uncomfortable in warm weather." **Fact!** Above about 13 °C a yak starts breathing faster, and at about 20 °C it stops grazing. It can barely sweat, which helps in the cold but not in the heat. [2]
- "Yaks and cows can’t have calves together." **Myth!** Yak–cattle hybrids are common: dzo in Tibetan areas, chauri in Nepal. The female hybrids are fertile, but the males are not. [14][21][25]
- "Yaks don’t get frostbite." **Fact!** No case of frostbite has ever been recorded in yaks, even on the tips of the ears or tail, though they graze at −40 °C. [2]

### Yak records

Superlatives and record holders, each checked against its source.

- Heaviest pack load: A domestic yak in Qinghai, China, 300 kg (at 4,100 m, 82% of the yak’s own body weight) [17]
- Highest pack work: Pack yak steers, 7,200 m (terrain that pack yaks can cross) [2]
- Coldest grazing: Yaks in Naqu, Tibet, −42 °C (the coldest air temperature recorded where yaks still feed and move) [2]
- Longest hair: Yak skirt, up to 70 cm (the fringe hanging from flanks and belly) [1]
- Biggest horns: Wild yak bull, 99 cm (longest horn in the species account, measured along the outside curve) [1]
- Oldest yak: A yak in captivity, 26.3 years (the record in the AnAge longevity database) [24]
- Biggest yak country: China, ≈94% (13.3 million of the world’s 14.2 million domestic yaks in a 2003 count) [6]
- Rarest coat: Golden wild yak, ≈2% (of wild yaks around the Aru Basin, northwestern Tibet, have a golden-brown coat) [1][6]

### A yak’s year

Life on the plateau follows the seasons: a long, hungry winter and a short, green summer.

- **November–April**: Winter pastures. Herders move their yaks to lower, sheltered winter pastures. Yaks break through snow to reach old grass, and wild yaks eat snow for water. [3][2][13]
- **Late winter**: The hungry time. Grass is short and scarce. Adults can lose 25–30% of their weight, and heavy snowfalls can kill many animals. [12][3]
- **May**: Calves arrive. Calves are born from March to August, most in May, weighing 10–16 kg. Wild calves in the Chang Tang arrive from mid-May to June. [22][18][1]
- **May–June**: Moult and shearing. The winter down loosens. Herders shear the yaks or comb out the soft down before it falls off. [5][3]
- **June–August**: Summer feast. Herds move up to summer pastures. A yak can eat 28–38 kg of grass in 10 hours and regains its winter losses. [3][2][12]
- **July–autumn**: Breeding season. High on the plateau, cows come into season from about July. Bulls grunt, wallow and show off side-on to rivals. [22][1]
- **Autumn**: Winter coat. Thick hair and a soft woolly down grow in, ready for a winter of −30 °C and colder. [5][2]

### Wild yak vs domestic yak vs cow

Domestic yaks descend from wild yaks. Both are close cousins of cattle, but built for a very different world.

| | Wild yak | Domestic yak | Cow (Holstein) |
|---|---|---|---|
| Scientific name [1][11] | Bos mutus | Bos grunniens | Bos taurus |
| Where it lives [1][12][11] | Tibetan Plateau, 3,000–5,500 m | Herded mostly at 3,000–5,000 m | Farms worldwide, mostly in the lowlands |
| Weight [1][18][23] | Bulls ≈1,000 kg; cows ≈350 kg | Bulls 235–594 kg; cows 188–314 kg | Dairy cows ≈624 kg |
| Shoulder height [21][1][18][23] | Bulls 1.5–2 m | Bulls 117–138 cm | Dairy cows ≈149 cm |
| Coat [1][19] | Long skirt and woolly down; black-brown | Same coat; black, brown, piebald or white | Short hair |
| Voice [1][14] | Grunts; bulls bellow | Grunts | Moos |
| Pregnancy [1][22][26] | 258–270 days | ≈258 days | ≈279 days |
| How many [1][12][27] | ≈15,000–20,000 | ≈16 million | ≈1.58 billion cattle of all kinds |
| Red List [28][29] | Vulnerable | Not evaluated (domestic) | Domestic animal |

Domestic yaks were tamed from wild yaks roughly 7,300 years ago.

### Are wild yaks endangered?

Domestic yaks number in the millions, but wild yaks are rare and listed as Vulnerable.

- **IUCN Red List:** Vulnerable (VU). Roughly 15,000–20,000 wild yaks remain, almost all on the Tibetan Plateau in China. In Nepal they were thought to be gone until two were seen in Upper Humla in 2014. [28][30][1][12][31]
- IUCN Red List, assessed 2016
- **Threat: Poaching**: Wild yaks were hunted heavily in the past and illegal hunting still happens. In Hoh Xil, female herds moved to steeper slopes after heavy poaching. [1][13][32]
- **Threat: Mixing with domestic yaks**: Wild and domestic yaks interbreed, so domestic genes spread into wild herds. Scientists call this a major long-term threat. [31][32]
- **Threat: Competition and lost habitat** (≈31% unprotected): Livestock compete with wild yaks for grass, and their habitat is being damaged and broken up. About 31% of wild yak habitat lies outside protected areas. [32]
- **Threat: Climate change**: Wild yaks live between the tree line and the glaciers. As it warms, parts of their range are expected to shrink and split up. [33]
- **Helping: Full legal protection**: Wild yaks have top-level (Class I) protection in China, and hunting has been banned since the early 1990s. International trade has been banned under CITES Appendix I since 1975. [1][34]
- **Helping: Big reserves**: The Chang Tang, Arjin Shan and Hoh Xil reserves protect the core of the wild yak’s range. [1][32]
- **Helping: Safe places for the future** (≈64%): Scientists have mapped climate refuges, covering about 64% of today’s habitat, that should still suit wild yaks in 2070. [33]
- **Domestic yak** (NE): Not assessed by the IUCN, because it is a domestic animal. About 16 million live across the high mountains of Asia. [29][12]

### Yak signals and body language

- The herd bunches tightly, calves in the middle: Danger nearby, often wolves. The adults face outwards. [1][2]
- Loud snorting from a wild herd: A warning. Threatened wild yaks may run off or charge. [15]
- A cow with a newborn calf turns towards you: She is very protective and may attack, even from the side or behind. Keep well away. [22]
- Two bulls stand side-on, 3–6 m apart: Breeding-season showing off. It can turn into sparring. [1]
- Rolling on the ground or wallowing: Yaks roll like horses, unlike other cattle. In the breeding season bulls also wallow. [2][1]
- Galloping with the tail held up: How yaks run at full speed. Herders even hold yak races. [2][17]

### Looks

- **Wild yak**: Jet black to dark brown, with a silver-grey stripe along the back and grey-white hairs around the muzzle. Bulls are huge: about 1,000 kg. (Vulnerable: roughly 15,000–20,000 left in the wild) [6][1][12]
- **Black domestic yak**: Dark like its wild ancestor but much smaller: domestic bulls weigh about 235–594 kg. It lacks the wild yak’s grey muzzle hairs. (Milk, butter, wool, pack work and dung for fuel) [18][6][4]
- **White and piebald yak**: Patched black and white, or all white. The white-spotting genes most likely came from cattle long ago. About 2–3% of yaks are white. (The Tianzhu White breed of Gansu, China: white hair dyes easily and is highly valued) [19][20][14]
- **Calf**: Born weighing 10–16 kg, mostly in May. Wild calves grow fast: at 3 months they weighed about 62.5 kg, against 33.6 kg for domestic calves. (Mothers guard their calves fiercely and know them by smell) [18][21][22]

### Yak quiz

1. Why is the domestic yak called Bos grunniens? **It grunts.** Grunniens means “grunting”. Yaks grunt instead of mooing. [14]
2. What does mutus, in the wild yak’s name Bos mutus, mean? **Mute.** It means “mute”, but wild yaks are actually quite noisy. [1]
3. How cold can it get while yaks still feed and move normally? **−40 °C.** Yaks graze normally at −30 to −40 °C. [2]
4. What is a yak’s hump built on? **Long spines on the backbone.** Extra-long spines stick up from the backbone and hold up the hump. [1]
5. Where do yaks sweat? **Only on the muzzle.** Tests found sweat only on the muzzle. Hardly sweating helps keep heat in. [2]
6. How heavy were yak lungs compared with local cattle lungs? **About twice as heavy.** Yak lungs weighed 3.7 kg, cattle lungs 1.8 kg. [2]
7. What do wild yaks do for water when streams freeze? **Eat snow.** Wild yaks eat snow. Females stay close to snow patches in winter. [13][1]
8. What is a normal load for a pack yak? **60–80 kg.** Pack yaks usually carry 60–80 kg for 20–30 km a day. [17]
9. What is a yak–cattle hybrid called in Tibetan areas? **Dzo.** A dzo. In Nepal it is called a chauri. [21]
10. What is the wild yak’s IUCN Red List status? **Vulnerable.** Wild yaks are Vulnerable, with roughly 15,000–20,000 left. [28][12]
11. In which month are most yak calves born? **May.** Calving runs from March to August and peaks in May. [22][18]
12. Above which temperature does a yak start to breathe faster? **13 °C.** Above about 13 °C. At 20 °C yaks stop grazing. [2]

### Sources (checked 2026-10-16)

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3. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO, Bangkok. Chapter 8: Management of yak.](https://www.fao.org/4/ad347e/ad347e0j.htm)
4. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO, Bangkok. Chapter 10: Products from yak and their utilization.](https://www.fao.org/4/ad347e/ad347e0l.htm)
5. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO, Bangkok. Chapter 6: Fibre production and hides.](https://www.fao.org/4/ad347e/ad347e0f.htm)
6. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO Regional Office for Asia and the Pacific, Bangkok. Chapter 1: Origins, domestication and distribution of yak.](https://www.fao.org/4/ad347e/ad347e05.htm)
7. [Durmowicz AG, Hofmeister S, Kadyraliev TK, Aldashev AA, Stenmark KR (1993). Functional and structural adaptation of the yak pulmonary circulation to residence at high altitude. Journal of Applied Physiology 74(5):2276–2285.](https://doi.org/10.1152/jappl.1993.74.5.2276)
8. [Anand IS, Harris E, Ferrari R, Pearce P, Harris P (1986). Pulmonary haemodynamics of the yak, cattle, and cross breeds at high altitude. Thorax 41(9):696–700.](https://doi.org/10.1136/thx.41.9.696)
9. [Zhang Z, Xu D, Wang L, et al. (2016). Convergent evolution of rumen microbiomes in high-altitude mammals. Current Biology 26(14):1873–1879.](https://doi.org/10.1016/j.cub.2016.05.012)
10. [Weber RE, Lalthantluanga R, Braunitzer G (1988). Functional characterization of fetal and adult yak hemoglobins: an oxygen binding cascade and its molecular basis. Archives of Biochemistry and Biophysics 263(1):199–203.](https://doi.org/10.1016/0003-9861(88)90628-5)
11. [Qiu Q, Zhang G, Ma T, et al. (2012). The yak genome and adaptation to life at high altitude. Nature Genetics 44:946–949.](https://doi.org/10.1038/ng.2343)
12. [Jing X, Ding L, Zhou J, Huang X, Degen A, Long R (2022). The adaptive strategies of yaks to live in the Asian highlands. Animal Nutrition 9:249–258.](https://doi.org/10.1016/j.aninu.2022.02.002)
13. [Berger J, Schaller GB, Cheng E, Kang A, Krebs M, Li L, Hebblewhite M (2015). Legacies of past exploitation and climate affect mammalian sexes differently on the roof of the world – the case of wild yaks. Scientific Reports 5:8676.](https://doi.org/10.1038/srep08676)
14. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO, Bangkok. Chapter 2: Yak breeds.](https://www.fao.org/4/ad347e/ad347e06.htm)
15. [Oliphant M (2003). Bos grunniens (yak). Animal Diversity Web, University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Bos_grunniens/)
16. [Lamichhane S, Shrestha B, Tharu BPC, et al. (2025). Narrow dietary niche with high overlap between snow leopards and Himalayan wolves indicates potential for resource competition in Shey Phoksundo National Park, Nepal. Ecology and Evolution 15(1):e70873.](https://doi.org/10.1002/ece3.70873)
17. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO, Bangkok. Chapter 6: Draught performance.](https://www.fao.org/4/ad347e/ad347e0g.htm)
18. [Wiener G, Han J, Long R (2003). The Yak, 2nd edn. FAO, Bangkok. Chapter 6: Production characteristics – Growth.](https://www.fao.org/4/ad347e/ad347e0c.htm)
19. [Zhang MQ, Xu X, Luo SJ (2014). The genetics of brown coat color and white spotting in domestic yaks (Bos grunniens). Animal Genetics 45(5):652–659.](https://doi.org/10.1111/age.12191)
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## Measurements & details

- **Length:** 250-330 cm
- **Weight:** 250-1000 kg
- **Lifespan:** 15-26 years
- **Litter Size:** 1
- **Gestation:** 258-270 days

## Diet & Feeding

Yaks are plant-eaters who graze on tough grasses and small plants found in high mountains.

- **Primary Foods:** Grasses, Sedges, Mosses, Lichens, Herbs
- **Foraging Method:** Grazing

## Ecological connections

- **Eaten by:** [Snow Leopard](https://www.snappit.app/explore/snow-leopard) (*Panthera uncia*) — Snow leopards take domestic yaks in some areas.
- **Eats:** Purple Stipa Grass (*Stipa purpurea*) — A common grass species grazed by yaks on the plateau.
- **Eaten by:** Grey Wolf (*Canis lupus*) — Wolves are one of the main wild predators of yaks. A threatened herd bunches up, with the calves in the middle.

## Traits

- [Wildlife](https://www.snappit.app/explore/traits/wildlife): Wildlife encompasses all undomesticated animal and plant life existing in their natural habitats.
- [Furry](https://www.snappit.app/explore/traits/furry): Furry describes animals possessing a dense covering of soft hair or fur.
- [Social](https://www.snappit.app/explore/traits/social): Social animals live in organized groups, cooperating for survival benefits such as foraging, defense, and raising offspring.
- [Horned](https://www.snappit.app/explore/traits/horned): Characterized by having one or more hard, permanent, pointed projections on the head.
- [Herbivorous](https://www.snappit.app/explore/traits/herbivorous): This trait characterizes organisms whose diet consists entirely or primarily of plant material.
- [Mountain](https://www.snappit.app/explore/traits/mountain): This habitat trait identifies species found in mountainous regions, characterized by high elevation, steep slopes, and varying climate zones.

## Collections

- [Mammals](https://www.snappit.app/explore/collections/mammals)

## Safety

**Danger:** 3/5 · Moderate

Yaks are big and easily startled. Never approach one, especially a mother with a calf. Stay with an adult and keep well away.

## Frequently Asked Questions

### How to identify Yak?

Compare ears, muzzle, tail, feet and coat markings. Size is hard to judge without something nearby for scale, and young mammals may not have adult coloring yet. Mammal Identifier: upload a photo and compare the visible details.

### How long is Yak?

250-330 cm

### How much does Yak weigh?

250-1000 kg

### How long does Yak live?

15-26 years

### What does Yak eat?

Yaks are plant-eaters who graze on tough grasses and small plants found in high mountains.

### Where is Yak usually found?

Mountain regions

### How many babies does Yak usually have?

1

## Where to spot

- [Naturschutz-Tierpark Görlitz](https://www.snappit.app/guides/places/naturschutz-tierpark-g-rlitz) — Saxony, DE · Zoo

## More Mammals

- [Eastern Fox Squirrel](https://www.snappit.app/explore/eastern-fox-squirrel) (*Sciurus niger*)
- [Eastern Cottontail](https://www.snappit.app/explore/eastern-cottontail) (*Sylvilagus floridanus*)
- [Eastern Chipmunk](https://www.snappit.app/explore/eastern-chipmunk) (*Tamias striatus*)
- [California Ground Squirrel](https://www.snappit.app/explore/california-ground-squirrel) (*Otospermophilus beecheyi*)

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Source: [Yak: Characteristics, Facts & Places to See — Snappit](https://www.snappit.app/explore/yak)