According 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.