Bright moonlight discourages the movements of many strictly nocturnal serpents. Metaphorically, a full moon is like a person standing outside their burrow pointing a flashlight at them. Bright moonlight makes snakes more vulnerable to human capture and other predators. Coyotes (Canis latrans) and owls enhance their vision using moonlight, improving hunting success, whereas snakes travel efficiently without light using chemosensory and for more specialized serpents by heat-sensing pit organs. Reptiles active in clear moonlight expose themselves to the unnecessary risk of predation.
Full moons have also brought people "luck," but luck is subjective. If a person wants Western Banded Geckos
Geckos (Coleonyx variegatus), which span all moon phases, or California Rosy Boa (Lichanura orcutti), rattlesnakes (Crotalus spp.), or other occasionally diurnal or crepuscular species, the moon phase does not really matter. Those species will be active, yet in fewer numbers. Nocturnal snakes, like California Lyre (Trimorphodon lyrophanes) and Desert Night snakes (Hypsiglena chlorophaea), will be out too, but mostly in the shadow of ridges, before moonrise, or when the moon is obscured by clouds. A bright moon can also work in a person's favor, it helps to narrow down which slope to explore at night. Some biologists have learned to avoid those exposed to the glow, spending more time in the shadows. One lengthy study in June 2003 involved driving remote paved roads through Inyo and San Bernardino counties from sundown to sunup during a full moon, with only a banded gecko for the effort. With such poor results, it is not surprising that some herpetologists have developed a loathing for the full moon. This brief post does not address the importance of humidity or air pressure, they also contribute to the levels of success.
*Since the moon cycles are ever-changing, the below moon chart is not included in the book.