Field Herper.com

This is my first post with the Reptile and Amphibian Blogging Network (RAmBlN), for Darwin Day! There are a lot more posts coming up – more info at the RAmBlN Facebook Page or Website. The topic for this series is Herps Adapt, showing some of the unique adaptations that have helped Reptiles and Amphibians survive. Also today, take a look at Bree Putman’s post Rattlesnakes’ Superpower: Seeing in the Dark

In Phoenix, we are are fortunate to have 2 of the largest city parks in the world. To visit these parks is not what most think of as visiting a city park – they are extensive native desert landscapes, criss-crossed with trails and visited by hundreds of people every day. The wildlife in these parks is intact, and for many, where iconic desert animals like the coyote and rattlesnake are first met. For those who visit the parks on a regular basis, the occasional rattlesnake sighting is unavoidable.

At education events and discussion with home owners in the area, the first sighting of a sky-blue rattlesnake at our table or unexpectedly appearing in the backyard generates comments such as “I like the albino rattlesnake”, or “Is this real?”. Nearly universally, these individuals are surprised to learn that these pretty blue snakes are one of the more common rattlesnakes that live on the mountain, and that they walk right by them on every hike. Why then, have very few of these hikers and foothills-dwellers ever heard of the speckled rattlesnake?

The reason, upon seeing this snake, is obvious. I photographed this snake within 10 feet of a busy hiking path, while dozens of runners and mountain bikers passsed by:

The Southwestern speckled rattlesnake (Crotalus mitchellii pyrrhus) in this photo (first posted here) is perfectly adapted to look exactly like the rocks where it lives. Even down to the smallest detail of the eye and the flecking frequency within the rock, the disguise is complete. Even with the snake a few feet in front of the observer, in the right conditions it can be difficult to discern the animal’s shape. This makes them both incredibly specialized predators, and notoriously difficult to find. I have personally worn out more than a couple pairs of hiking boots learning how to find speckleds at this locale with regularity.

Of all of the rattlesnakes, few would deny that specks are the king of camo, but there is even more to the way these guys do it. On any other mountain range where these snakes are found, they look completely different. Each  population of speckled rattlesnake is adapted not only to look like rocks, but exactly the  color and composition of rocks found only in that location. The granite at South Mountain is a faint sky-blue color, flecked with white or cream quartz; the speckled rattlesnakes here are identical. A short drive to Camelback mountain, another very popular hiking area, changes everything. 

Here is a photograph of Camelback Mountain (phoenix.gov). Take a guess what the speckled rattlesnakes there look like.

Just as amazingly fine-tuned as at South Mountain, the speckled rattlesnakes are perfectly suited to this red-rock environment:

 

This theme continues at each range where the speckled rattlesnake lives. The variation, even within a relatively short distance, can be extreme.

The most amazing example of this is found in the quartz-rich rock of Western Arizona. The speckled rattlesnakes have adapted to be porcelain-white, making them both beautiful and an unfortunate high-value target of poachers. Here is one found in 2013:

 

In stark contrast, speckled rattlesnakes in North Central Arizona have adapted to the pink and orange rock, with beautiful results.

To show even more variation, I’ve asked friends to contribute photographs of speckled rattlesnakes found throughout their range. This is by no means an complete representation of the variation of this one sub-species of snake, but it does show their amazing gamut of unique instances of specialized camouflage.

Enjoy the flood of speckled rattlesnake photos, and if you ever go hiking in South Mountain park, make sure to double check the rock you’re about to sit on!

Contributions from friends:

Bill BoaRd
Riverside County, CA

Southwestern Speckled Rattlesnake, Crotalus mitchellii pyrrhus

 

Kevin Butts
S. Nevada

 

Richard Legere
Maricopa County, AZ

 

Brandon Harmon
Maricopa County, AZ

 

Josh Jones
Maricopa County, Arizona

 

Kris Haas
Mojave County, AZ

 

Kris Haas
Yavapai County, AZ

 

Kris Haas
Maricopa County, AZ

 

Kris Haas
La Paz County, AZ

 

Kris Haas
Yuma County, AZ

 

Dave Holland
S. California

 

Dave Holland
Maricopa County, AZ

 

Bill Love

 

Kat Parks
Maricopa County, AZ

 

Thanks for making it to the end. Check out the other posts from the Reptile and Amphibian Blogging Network (RAmBlN), for Darwin Day, and like the page on facebook: RAmBlN Facebook Page

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