Southwestern Speckled Rattlesnakes (Crotalus pyrrhus) are commonly seen by hikers in the Phoenix area at popular parks, even those entirely within the city. They have a relatively extreme level of camouflage for a rattlesnake, and many people are surprised to learn just how many rattlesnakes they walk by even at the most heavily-hiked parks in the city. This is one of several hundred that inhabit one of these parks, found on a hillside below a trail.
A Southwestern Speckled Rattlesnake (Crotalus pyrrhus) resting in a small cave during the hottest time of the year. This location receives almost no sun, due to its depth and aspect, which makes it an ideal aestivation site.
Snakes, as do other ectothermic (cold-blooded) animals, do regulate their body temperature by managing external forces. It’s more than just basking in the sun … they also spend a lot of time and energy trying to stay cool. For animals in Arizona, that can be a challenge. These sites, where they return each year when temperatures become lethal, are just as important as a winter hibernation den for rattlesnakes in cooler areas.
A mature Black-tailed Rattlesnake we found on a late-night hike near Phoenix. These snakes live in mountainous or hilly areas, where they are often confused with a number of other rattlesnake species.
A Southwestern Speckled Rattlesnake (Crotalus pyrrhus) found in Maricopa County several years ago. This species is among the most common snakes encountered at most parks across the Phoenix metro area.
Close up with a Sonoran Sidewinder, showing off its “horns”. They are actually soft scales that rise above the eye, a feature they share convergently with unrelated vipers in deserts on the other side of the world. This is one of several seen on a warm evening last year near Phoenix.
A Tiger Rattlesnake found in a very heavily visited park. This old snake is one of just a handful of Tiger Rattlesnakes that are known to remain in the park, and likely is very good at evading detection by hikers. This deconstructed, purple-ish tone look is typical for the species in the area. It now carries a PIT tag that will confirm its identity on future sightings.
A Mojave Rattlesnake from the Phoenix area. This brown and tan color is typical of this species in the area, though some of the more famously greenish ones do pop up as well. This one follows all the rules, with a clearly visible tail with bands of a roughly 2:1 white to black ratio, half yellow proximal rattle segment, and eye stripe extending beyond the corner of the mouth.
But what people who are very experienced use to identify a snake like this is not any of those features in particular. It’s the overall appearance, or gestalt. The “cleaner”, less speckled and chaotic pattern, slighter and more angular head shape, and outward appearance as a whole just hit as “mojave” in the mind upon sight. This isn’t to say, of course, that the features listed aren’t important, but all can be variable and fail an observer from time to time. It’s worthwhile, once a person has learned to identify these animals reliably based on details, to “zoom out” and look at the whole animal. Eventually, a Mojave Rattlesnake would stand out from similar-looking species in the same way you can likely tell the difference between a yellow lab and a retriever.
Sonoran Sidewinders are common snakes found in flat, sandy areas of southern Arizona. They used to inhabit nearly the entirety of the Phoenix metro valley, with records below Camelback Mountain and throughout Scottsdale. Of the rattlesnake species in the region, however, they are the first to die out as soon as an area is closed in by roads. This one was found near Phoenix in an area where they are still common, but future development will change that dramatically, soon.
A Southwestern Speckled Rattlesnake from the Phoenix area. This species of snake has a huge gamut of colors and patterns possible throughout its range. Even within relatively nearby locales, it can be extreme. Just about ten miles from where this snake lives, they are red or orange.
A Southwestern Speckled Rattlesnake from the Phoenix area. In some locations, they can be a pretty brick red like this one. These are the second most commonly encountered rattlesnake by hikers in the central Phoenix parks.
