Desert Diaries

What do ‘Goldie Locks’ and Rattlesnakes Have in Common?

Photo: Zach West

They both like the temperature to be ‘just right’, of course! Puns aside – rattlesnakes, like many other animals here in the Sonoran Desert, practice a desert survival strategy known as avoidance. They refrain from exposure and surface activity when it’s too hot during southern Arizona’s summer months, and the cold limits their activity during the winter.

Speckled rattlesnake (Crotalus mitchellii). Photo: Zack West

Spring time is rattlesnake time, with warm day time temps and cool evening temps creating ideal conditions for late morning to mid-afternoon activity during daylight hours. Summer time is also rattlesnake season, but the long, sweltering days are simply too hot to negotiate. Activity switches to almost exclusively nocturnal, with some movement in the early morning hours as they seek out cooler retreats below ground. Fall is an excellent time of year to observe rattlesnakes as well, as the sharp edge of summer’s heat yields to shorter, cooler day temps.

Sidewinder rattlesnake (Crotalus cerastes cercobombus). Photo: Zack West

So what’s up with the cold months of Winter? Sonoran Desert winters are as varied in temperature as Goldie’s three bowls of porridge. They are often a vacillating medley of transient temperature fluctuations, and rattlesnakes have adapted to take full advantage of this! Most of our winters here in the Sonoran Desert have strands of warm days woven in with the tapestry of colder ones. Rattlesnakes, being ectothermic creatures that rely on ambient temperature to help regulate their body temperature, emerge briefly from winter burrows to warm up a bit before returning to their subterranean retreats.

Chihuahua ridge nosed rattlesnake (C. Willardi Silus). Photo: Zack West

We here in the Herpetology department like to say that rattlesnake season in the Sonoran Desert is January 1 to December 31; it’s year ‘round! So it’s not about day or night when it comes to rattlesnake activity; they are active both day and night as the temperature allows. To summarize, Spring is in the air, and rattlesnakes are on the move, going about their rattlesnake business. It’s not just about Spring though; rattlesnake season is most of the year here in the Sonoran Desert!


Here are a few fun facts about rattlesnakes that, for me, made them more fascinating and less scary:

Banded Rock rattlesnake (Crotalus lepidus klauberi). Photo: Zack West

Written by Howard Byrne, ASDM HIIZ Keeper.