Reproduction: Sexual maturity is attained at about five years of age. The rutting
season starts during the late autumn. The bull accompanies four to five breedable
cows during this period. The female comes in heat after 21 days and estrus lasts
for 24-72 hours. The single young is born after a period of 258-270 days gestation.
The reproductive life of a female yak is reported to be 15-16 years.
Behaviour: Bulls are generally solitary. However, they may be found in small groups of two to three animals. Cows and calves, on the other hand, form a large herd comprising a large number of animals. The grown-up bulls make smaller groups of their own. They graze both in morning and in evening.
Life span: Yaks are known to live for twenty five years.