I saw this Tiger Rattlesnake moving along a rocky drainage on a hot summer morning. The wash was full of deep caves and access to cooler temperatures that it needed to survive the hottest time of year. She was also gravid, and in time she gave birth in these same caves.
This Southwestern Speckled Rattlesnake, at the time this photo was taken, was very gravid (pregnant). She was in a cool area with higher ambient moisture, which is a special place during the heat of the summer in Arizona. She’s still there this year, though at the time I saw her, she was not notably gravid.
A Tiger Rattlesnake from the Phoenix area. The blue-grey base color fading to pink with dark grey bands is a standard look in the area. These snakes are common in popular hiking areas, yet most people who frequent them for a lifetime will never see one because of their cryptic nature.
A Southwestern Speckled Rattlesnake found in ambush at sunup on a hot day in Arizona. Nearby, a cave with several more has been used as an aestivation site to avoid death in the summer months.
This photograph was taken in 2014. In recent years, the site has been abandoned, most likely due to increased human activity, based on evidence and observation of similar sites in the region.
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.
