Monday, September 5, 2016

Western Diamondback Rattlesnake

Night falls over the semi-desert grassland outside of Elgin, Arizona. The Mustang Mountains rise above the acres of dry grass like a silent shadow. Common Poorwills, Common Nighthawks, and Elf Owls call out from the dark among the chirping of crickets. Nestled in the grasses, another creature slowly explores the land looking for a meal. His journey brings him to a gravel driveway...

Western Diamondback Rattlesnake Arizona
This gravel driveway sits right outside of the Appleton-Whittell Research Ranch dormitories. As he slowly slithers across the driveway, an unsuspecting field tech out on a night walk stumbles across the beautiful 4.5 foot long Western Diamonback Rattlesnake. The field tech runs back to the dorm, yells "SNAKE," and suddenly the horde of herp-loving techs and researchers scramble out of the dorm and toward the (probably confused) rattlesnake. This individual wasn't the first Diamondback of the field season; in fact, it was actually the 3rd individual that visited the dormitory!

Rattlesnake defense position
The Western Diamondback Rattlesnake, Crotalus atrox, is a species of venomous rattlesnake which ranges throughout the American Southwest from southern California to western Arkansas. A rather generalist when it comes to habitat preference, it can be found in a wide variety of places. They utilize habitats such as coastal plains, deserts, prairies, pine-oak forests, rocky hillsides, and more. They're a large species of snake, both in length and girth. Adults average between 3 and 5 feet long, with the occasional individual reaching upwards of 7 feet. You will often see images floating around the internet with people holding dead (yet giant looking) rattlesnakes. Oftentimes the captions will say it was a 10 foot, or 15 foot, or some other ridiculously-long rattlesnake. Those are all hoaxes which utilize the forced perspective camera trick. The record Western Diamondback Rattlesnake length is 92.5 inches, or 7.7 feet. For more info on these fictional giant rattlesnakes you see on Facebook and the like, check out David Steen's blog post on the "giant killed rattlesnakes."

Rattlesnake rattle

Of course, the name “rattlesnake” stems from the characteristic rattle at the end of the tail. This rattle is made of keratin, the same material that makes up our fingernails and toenails. The rattle consists of several overlapping hollow parts that when pulled against each other produce a dry rattling noise. To watch the individual pictured rattle, check out this video I took. As a general rule, snakes only want to bite as a last resort when they feel as if their life is directly threatened. When a rattlesnake feels threatened by a human, it will typically go through a series of actions. First, if it feels the threat level is low, a rattlesnake will simply sit still or try to escape the immediate area unnoticed. If a person continues to stay in the area, or moves closer to the snake, the rattlesnake will often begin to rattle (but not always). This rattling serves as a warning to potential predators and threats. By announcing that it is there to the threat, the rattlesnake is essentially saying "I see you, you see me, I'm letting you know that I am dangerous. Leave me alone and I will leave you alone." If the threat continues, however, the rattlesnake might resort to biting.

Bites by venomous snakes are extremely rare, however, and most bites that do occur happen when someone is either harassing the snake (e.g. trying to kill it) or if they accidentally step on it. Although bites by venomous snakes are serious, they're rarely deadly. In fact, of the 7,000-8,000 Americans who get bit by venomous snakes a year, less than 1% of those victims die. To put this in perspective, 9 times more Americans die each year from lightning strikes than snake bites. All in all, the fear of venomous snakes most Americans have is incredibly overplayed, and I think that is very important to point out. Snakes are not nearly as scary as what people think. Given respect and appropriate distance, rattlesnakes pose no threat.

Western Diamondback Rattlesnake

Unless you're a rodent, that is. If you were, then this is definitely not the face you would want to be staring down. Western Diamondbacks have been recorded preying on a wide variety of animals, from birds to reptiles to insects and more. However, mammals make up the vast majority of their diet. And when it comes to mammal prey, Western Diamondbacks love rodents. Oftentimes a Diamondback will position itself along a rodent path and wait for an unsuspecting mouse or packrat to scamper by. One lightning-fast strike later and the Western Diamondback has a nice meal.

Rattlesnake in the wild

It is always a pleasure seeing a snake of any species in the wild, but it's a wonderful day when you see any sort of rattlesnake. I've wanted to see a diamondback rattlesnake (either Eastern or Western, I'm not picky) for years now, and I was ecstatic to see as many as I did over the summer. There's just something magnificent about these beautiful, but sadly misunderstood, creatures.