Yak (Bos grunniens)


Class: Mammalia
Order: Artiodactyla
Family:    Bovidae
Size:    Length: Up to 11 feet (3.3 m)  Height: 5 to 6 feet (1.5 to 1.6 m) at the shoulder
Weight: 800 to 2,200 pounds (363 to 998 kg)
Diet: Grass, herbs and lichens
Distribution: Tibet and India
Young:  1 calf every other year
Animal Predators:  Unknown 
IUCN Status: Vulnerable
Terms: Male: Bull    Female: Cow    Young: Calf
Lifespan: Up to 25 years in the wild



       Yaks found in zoos are usually the domesticated type and are smaller than wild yaks.

       A yak tucks its legs under its shaggy fur to keep them warm when it lies down.

       The yaks scientific name Bos grunniens means grunting ox.


Wild yaks are all black in colour, as opposed to domesticated yaks, which can be white, grey, yellow, brown, or pinto (black and white together). Their heavy fur protects them from the bitter winds and snowstorms in the mountains. They have large horns. Their split hooves enable them to grip icy and rocky ground.



Yaks remain in high areas with permanent snow during the warmer months of August and September, while the rest of the year is spent at lower elevations. Their original range included central China, India, Bhutan and Nepal.


Feeding Habits

They feed mostly in the morning and evening, grazing on grass, herbs and lichens. Yaks need to drink water every day and will bathe in lakes and streams, even during extremely cold bouts of weather. 



Breeding occurs in September and October, with a single calf born nine months later, in June or July. Calves become independent at one year, but do not reach full size until six to eight years. 



The Tibetan people first domesticated yaks over 2,000 years ago. They are able to carry over 300 pounds (136 kg) of cargo over steep mountain paths, as well as providing milk, meat and hide. The milk is twice as rich as cows milk and is easily made into butter and cheese. Wild yaks live in herds of females and their offspring, and smaller herds consisting solely of mature bulls. They travel long distances to find food, and are capable climbers. Wild yaks travel in single file through snow, stepping into the footprints of the lead yak. With their heavy fur, they are sensitive to heat and remain in high, cool elevations during the summer months.



There are only a few hundred yak left in the wild, living mostly in the snow-covered mountains of Tibet at altitudes of 13,000 to 20,000 feet (3,962 to 6,096 m).  










Yak Wildlife Fact File, IM Pub, US