Evening can linger a long time in the desert and night can strike quickly as a cat’s paw. You watch the sun go down, turning the clouds above the Chisos red, painting Sierra del Carmen crimson, while a single golden shaft breaks through the clouds and hits El Pico like a spotlight. Then the sky goes smoky blue and mauve over the eastern mountains, and the clouds to the west turn ashen as burned out coals.
[Illustration: Texas banded gecko (adult)]
[Illustration: Twin-spotted spiny lizard]
[Illustration: Collared lizard (pregnant female)]
[Illustration: Texas banded gecko (young)]
[Illustration: Western diamondback rattlesnake]
[Illustration: The kangaroo rat and roadrunner exemplify adaptations for desert living. Neither drinks water, as a rule. The roadrunner gets its moisture largely from its omnivorous diet, which includes lizards and small rattlesnakes. It kills them with stunning blows of its beak. Its characteristic X-track provides good traction in sand. Agile and nimble, this 60-centimeter- (2-foot) long bird can fly, but it prefers to run, at up to 32 kph (20 mph). Mexicans call the roadrunner _paisano_, “fellow countryman.”
The kangaroo rat metabolizes both energy and moisture from seeds that contain less than 4 percent water. It has no sweat glands and cools itself by breathing. Its nasal passages, cooler than the rest of its body, condense breath moisture for retention. Its kidneys, among the most efficient in the animal world, excrete uric wastes as a concentrated paste, not as liquid, saving further precious water. Its deep burrow has a year-round relative humidity between 30 and 50 percent. These rodents sometimes fight with each other, leaping high into the air and striking at each other with their strong hind legs.]
You can see the nighthawk now against the pale and pearly afterlight, and a star pops out, then another and another. Suddenly, more stars seem to be twinkling than can possibly exist in the universe. In the absence of man-made light they are an overwhelming presence. The Milky Way stretches from horizon to horizon. Who can believe that our Sun is just a middle-sized star, and planet Earth a mere speck spinning on the fringes of that gorgeous luminosity?