If you’re by a desert spring in far northwest Arizona or southeast Nevada and hear a low chuckle followed by what sounds like fingers rubbing on a balloon, you may have stumbled upon a relict leopard frog.
Every winter, what sounds like a pack of baying hounds fills the air at Bosque del Apache National Wildlife Refuge in New Mexico. It’s not dogs, though, but birds—snow geese by the thousands, making loud, nasal, single-syllable honks.
If you look toward the eastern horizon just before dawn on a clear moonless night, you should see a ghostly white glow shining up through the dark sky. This is zodiacal light, caused when passing comets and colliding asteroids shed space dust. That dust scatters sunlight upwards well before sunrise.
Southwest deserts are a good place to see atmospheric phenomena called mirages. They occur where distinct layers of warm and cooler air form. When hot air is trapped below cooler air, entering light is inverted and bent upwards – forming an inferior mirage below the real object.