Bighorn sheep get the name "Bighorn" because of their horns. A male bighorn sheep is called "ram" and a female bighorn sheep is referred to as "ewe". Most people know bighorn because of their head-to-head combat between rams. Ram's horns can weigh up to 30 lbs and the bighorn sheep itself can weigh up to 300 lbs. Combat between rams can sometimes last over 24 hours. The mule deer is one of the natural competitors of bighorn sheep's. Normal bighorn sheep lifespan is about 8 - 15 years. Few bighorns do not need to drink water in the winter because of all the green vegetation that they can eat. In the summer though, bighorns need to drink water at least every 3 days. Researchers have seen bighorns drinking water as long as for 3 minutes. Normal bighorns lifespan is about 8 - 15 years.