There are more mundane adaptations, too. Many animals beat the heat by coming out only at night. Most snakes do this because summer daytime temperatures on the desert floor would kill them in minutes. Another simple way to beat this heat is to climb above it. Many human travelers pass through the summer desert quickly, headed for the higher and cooler Chisos Mountains.
Some insects use the same principle.
They merely fly straight up in the air a short distance, where it is significantly cooler. One walking beetle seems to rise up on stilts periodically, again to achieve critical distance from the desert floor's killing heat. If the Rio Grande interrupts the Big Bend country as a linear oasis, the Chisos Mountains interrupt it as a green island in a desert sea. As does the river, the mountains bring creatures you might not expect to find in desert areas, and several species are quite rare. Isolation provided the key.