Rattlesnakes: Species

Ten Things I Like About... Podcast

Summary: Even though rattlesnakes are only found in the New World, there are a plethora of cool species. Join Kiersten as she take a few close up looks at some wicked cool rattlesnakes.

For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean

Show Notes:

America’s Snake: The Rise and Fall of the Timber Rattlesnake by Ted Levin

Rattlesnake: Portrait of a Predator by Manny Russo

https://www.savethebuzztails.org

https://waterlandlife.org

https://www.fws.gov/specis/eastern-massasauga

https://www.desertmuseum.org

https://www.floridamuseum.ufl.edu

Music written and performed by Katherine Camp

Transcript

Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

(Piano music stops)

Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating.

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

This episode continues rattlesnakes and the second thing I like about this astounding reptile is the variety of species alive today.

Today we’ll start off with a little taxonomy. As a reminder taxonomy is the scientific classification of living creatures. It is a way of grouping plants and animals into families for easier study. Rattlesnake classification is as follows: Kingdom: Animalia (this means it’s an animal), Phylum: Chordata (roughly speaking they have a backbone), Class Reptilia (they are reptiles), Order Squamata (this contains lizards and snakes), Suborder Serpentes (snakes), Family Viperidae (a group of venomous snakes called vipers including rattlesnakes), Subfamily Crotalinae and two different genera including Crotalus and Sistrurus. Don’t worry there won’t be a test at the end of this episode!

Currently there are 32 accepted species of rattlesnake with 83 subspecies. Upon the advent of DNA testing, this number has fluctuated as scientists discover more information about family relatedness based on genetics versus physical characteristics or behavior. Basically what I’m saying is that this number may be correct today but different tomorrow.

The majority of species are found in Genus Crotalus and only three are classified in Sistrurus. There is one outstanding physical characteristic that separates the two genera. The scales on the top of the head of Genus Crotalus will typically be small and similarly shaped, while Genus Sistrurus will have a less uniform group of nine large scales on the crown of the head. There are always exceptions to the rule in Nature so this description is not a hard and fast rule, but a more general rule.

Before we look at some specific rattlesnakes more closely, let’s discuss where rattlesnakes can be found on the planet. Rattlesnakes are a New World animal which means they are found only in North, Central, or South America. They can be found from southern Canada to central Argentina with the most variety found in the southwestern United States and northern Mexico. A few are found on islands in the Caribbean such as Aruba.

The habitats they are found in vary from desert to semi-arid desert to prairie to timber woodlands. They did not evolve to tolerate rainforest habitat. Rattlesnakes can be found in areas that have a cold winter as long as they have dens to hibernate in to keep from freezing to death. In areas that are warmer, they have adapted to living near human suburbs because they are attracted to the mice and rats that are attracted to us. In areas that are colder and the need for a denning sit that remains undisturbed through the winter is crucial, they are struggling to survive.

Now that we know a little about rattlesnake taxonomy and where we can find them, let’s take a closer look at a few individual species.

One of the most well known rattlesnakes is the Diamondback. This snake is an icon of the wild west of the United States but there is an Eastern Diamondback as well as a Western Diamondback. The eastern Diamondback is native to the southeastern United States and can be found in the pinelands of Florida, the coastal plains of North Carolina and southern Mississippi through eastern Louisiana. The western diamondback is found throughout the western portion of the United States including Arizona, California, New Mexico, Oklahoma, Texas, and northern Mexico.

The two snakes are separate species in Genus Crotalus. The eastern Diamondback is Crotalus adamanteus and the western diamondback is Crotalus atrox. As their name suggests they have large diamond shaped patterning on their back. It begins behind the head and travels down to the tail. The diamond shapes will be darker than the base color of the snakes. The eastern diamondback is typically brown or gray with the base color darkening toward the tail where dark bands appear just before the rattle. The western diamondback base color ranges from light brown to dark brown to reddish brown depending on habitat with bright white and black stripping just before the rattle. Both diamondback snakes are some of the longest and heaviest rattlesnakes alive today with adults ranging from 2 1/2 feet to 7 1/2 feet.

Let’s look at one of the snakes in Genus Sistrurus. Sistrurus catenatus, the eastern Massasauga is a small but thick bodied rattlesnake found in the eastern portions of North America. This 1 1/2 foot to 2 1/2 foot snake is found in the northern midwest United States and Ontario, Canada. Their current range is much smaller than their historic range. They tend to favor shallow wetlands with surrounding upland areas that they use for hunting, breeding, and hibernating.

Coloration varies from gray to light brown, but some black individuals have been seen. The splotches that travel down the back are generally dark in color and resemble a colored in number eight. They will also have rows of smaller blotches down the sides of the body. The tail has a small rattle which sounds like the buzz of an insect when they are agitated.

Let’s travel down into South America and take a look at the only rattlesnakes found there. The South American Rattlesnake or Crotalus durissus is found in the Cerrado ecoregion of southern Brazil, Uruguay, Paraguay and northern Argentina. In Portuguese this snake is called “cascavel”. The cascavel typically makes its home in grasslands and savanna habitats although they are occasionally found in dry forests and open clearings in jungles.

Adults range in size from 2 1/2 feet to 6 feet in length. Base colors vary widely from yellow to light brown to reddish to dark brown or even gray. Some reports of greenish tinted specimens have seen seen near forested areas. They have two stripes that run from the top of the head down the neck that fade as the body gets larger. Diamond shaped patterning flows down the rest of the body terminating at the tail where the rattle begins. Like most other rattlesnakes they are a heavy bodied snake and they have one of the widest ranges of any rattlesnake. There are several subspecies of Crotalus durissus.

We’re going to look at one more species in depth and this is the one rattlesnake that doesn’t have a functioning rattle. That’s right, this rattlesnake doesn’t have a rattle. The Santa Catalina Island rattlesnake, Crotalus catalinensis, is genetically a rattlesnake but after years and years of living on an island they have lost their rattle. They do have the button, the base of rattle, but it comes off with every shed preventing a rattle from developing.

They are native to Isla Santa Catalina in the Gulf of California. Adults range in size from 2 feet to 2 3/4 feet. They can be found almost anywhere on the island and unlike other rattlesnake species they are often found hunting in trees. They are the most arboreal rattlesnake of any rattlesnake species. This may explain why they are more slender than any other rattlesnakes, as well. This is a lovely little rattlesnake with a grayish brown base color and large white-bordered diamond blotches along the back. The tail terminates in black and gray striping reminiscent of diamondback rattlesnake tails. These snakes can be a very pale gray with light brown blotches creating a stunningly beautiful pattern.

That is all for this episode of rattlesnakes. There are so many more cool species of rattlesnake but I had to restrain myself to my ten minutes limit. Thanks for joining me because the variety of species alive today is my second favorite thing about rattlesnakes.

If you're enjoying this podcast please recommend me to friends and family and take a moment to give me a rating on whatever platform your listening. It will help me reach more listeners and give the animals I talk about an even better chance at change.

Join me next week for another episode about rattlesnakes.

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This has been an episode of Ten Things I like About with Kiersten and Company. Original music written and performed by Katherine Camp, piano extraordinaire.