Being from Arizona, I figured why not choose one of the most incredible animals I have ever seen: The Rattlesnake! Rattlesnakes are "highly specialized, venomous reptiles with large bodies and triangle-shaped heads. They are one of the most iconic groups of North American snakes due to the characteristic “rattle” found at the tip of the tail." (nwf.org). There are a variety of different Rattlesnake species, and they are found in many parts of the United States and most of Latin America. This is because they are not picky about where they live, and easily adapt. They each have their unique traits and characteristics. Some rattlesnakes are brown, while some of them can be white. However, one thing they all share in common is their iconic rattle! While there are so many amazing things about the rattlesnake, such as it being a pit viper and having heat sensory organs on each side of the head, what I find most intriguing about this snake is how it came to have a rattle. Why would a snake have a rattle? I will explore how the Rattlesnake came to have its iconic rattle. 

It is easy to assume that the rattle of a Rattlesnake is full of beads or little rocks. However, it is hollow! According to the Missouri Department of Conservation, "the rattle is made of special hollow scales, made of keratin, on the tip of the snake’s tail. These scales are loosely connected." (mdc.mo.gov) This is fascinating because that means that the rattle is made up of the same protein as our nails and hair! The reason that the rattle makes that distinct sound is "When the rattlesnake vibrates its tail, the scales rapidly strike each other, causing a buzzing sound." (mdc.mo.gov). What is even more interesting is that Rattlesnakes are born with just a single button on the tip of the tail, and each time they shed, they add more layers to their rattle throughout their lifespan. 

On the left is a video showing a breakdown of the inside of a rattlesnake's rattle, as well as a brief overview of Rattlesnakes and their behavior. 

To get the answer to this question, we must look at where the first rattlesnakes originated from. According to the Missouri Department of Conservation, "Rattlesnakes evolved on the Great Plains where hooved animals, like bison and elk, roamed." (mdc.mo.gov) Because they could not be seen by these much larger animals, there was a constant risk of being trampled to death by the unknowing animals. So, they came to get the rattle to protect themselves, which prevented them from being trampled, or from having to run away. This allowed them to conserve energy, and also be safe. Now, animals would know exactly where the Rattlesnake was any time the rattlesnake wanted its presence to be known. 

On the left is a video demonstrating the auditory and visual warning given by a rattlesnake. Notice how the snake is in an offensive position, and it is giving auditory sounds to let all animals know to stay away. 

A key question asked when something new is tried is: "Did it work?", and the same applies to the Rattlesnake rattle. According to the San Diego Zoo, rattlesnakes are "considered to be the newest or most recently evolved snakes in the world." (https://animals.sandiegozoo.org) This, however, has not stopped the rattlesnakes from being among the most efficient predators in the world. While rattlesnakes use their rattle to warn off predators, they also distract prey. There have also been recent developments showing that rattlesnakes can change the frequency of their rattles! This would mean they can trick listeners into believing the snake is further or closer away than the listener thinks. This leaves many questions and openings for further research. One question would be if they can use their rattle for mating calls. Who knows? But one thing is clear: while there is plenty of studying and research to be done, it can be said with confidence that the rattle has proved to be an extremely effective product of evolutionary adaptation. Even if the rattlesnake is no longer exclusive to the Great Plains, its ability to surpass language barriers with a simple rattle saves time and energy, and potentially its life. A rattle can scare off many different threats, and it is a trait that makes it one of the hardest snakes to miss. 

• Of the 30 recognized rattlesnake species, Arizona is home to 13, including the famous Western Diamondback. 

• The Arizona Diamondbacks are named after the famous snake!

• Like most snakes, rattlesnakes cannot hear most sounds and instead rely on vibrations in the ground. 

• In the animated movie Rango, one of the main antagonists is called "Rattlesnake Jake", based on a Western Diamondback. 

• Rattlesnakes are very adaptable and are not picky when it comes to habitat. They can live in almost any terrain, as long as there are burrows to keep warm since they cannot regulate their body temperature. 

• Rattlesnakes are easy prey for King Snakes, who are very resistant to rattlesnake venom. 

• In the winter, rattlesnakes may use the same den as their mothers, and the same den may be used for generations!