How do desert bighorns deal with excessive summer heat? 

Ram drinking at rock poolAccording to author Mark Jorgensen, “Desert bighorn sheep are well adapted for extreme temperatures. Studies have revealed that rams and ewes can withstand dehydration rates of over 20% of their body weight. By comparison, a human will usually lose consciousness at a water loss of 5-7% of body weight.”

The sheep also lose heat to the air. “If the air temperature on a sunny day were 103 degrees Fahrenheit and a bighorn temperature were 105 degrees Fahrenheit, body heat would be released from the sheep into the air, rather than be absorbed from the air as it would be in a human.”


Nevertheless, the summer heat ties the sheep to permanent water resources. “In the long run, reliable surface water is needed to maintain a healthy population of desert bighorn in a mountain range.”

Learn more in Desert Bighorn Sheep: Wilderness Icon.