A domesticated yak at Yamdrok Lake in Tibet. The animals are important to Tibetan culture, and have been kept for thousands of years. The yaks are a method of transportation and serve as beasts of burden. Their feces are a source of fuel, and their milk can be used for butter, which is then made into sculptures or consumed.Photograph: Dennis Jarvis
 | This picture of the day has been featured on Portal:Mammals. |