WESTERN DIAMONDBACK RATTLESNAKE IN NORTHWEST WILDLIFE

Among the many varieties of rattlesnakes found in North America, the Western Diamondback Rattlesnake stands out due to its unique triangular shaped head, a feature unique to its species. It is also unique in its coloring and diamond shaped markings. It lives on dry, shrub covered rocky terrain and preys on small mammals.

The Western Diamondback Rattlesnake is one of the largest rattlesnakes found in North America, growing to a length of 60(0.6 meters) to 160 centimeters (1.6 meters). They weigh between 4 ounces (113 grams) and 20 pounds (9 kilograms). The Western Diamondback Rattlesnake lives to 30 years on average, ten to twenty years longer than other rattlesnake species.

Western Diamondback Rattlesnake

The Western Diamondback Rattlesnake is noted not only for its size, but also its unique appearance. It is characterized by a plump body, a short tail, eyes with vertical pupils, and a broad triangular head which is distinct compared to the rest of its body. Its coloring ranges from yellowish-gray to pale blue or pinkish with dark diamond-shaped markings down its back. These marks are lighter in the center with dark edges that are
surrounded by a light border making for a very interesting pattern surrounding the whole body of the snake. These marks are irregularly dispersed along the dorsal side of the snake.

The rattlesnake also has a rattle at the end of its tail. Its rattle is made up of the last scale left when the snake undergoes molting (the process of shedding its skin).With each molt, the snake gains a new layer to its rattle at the same time as the old one is shed. The rattle is made of rings or segments of keratin, the same material found in human fingernails. The rattle is a very important aspect of the snake’s overall anatomy because it
enables it to ward off predators. The Western Diamondback Rattlesnake is often confused with many other snakes with blotch-like markings such as Gopher snakes whose blotches have a checkered pattern, Hognose Snakes which have a distinctly upturned snout and large blotches on their belly and Night Snakes which have vertical pupils that are much smaller and more slender than those of the Western Diamondback Rattlesnakes. Although all of these snakes may resemble the rattlesnake in some way, none have its distinct triangular head and rattle.

Western Diamondback Rattlesnake

The Western Diamondback Rattlesnake belongs to the Viperidae family of reptiles (scientific name Crotalinae) which are characterized by long teeth called fangs. These fangs are used to subdue and kill prey. They are sometimes left with the prey and are replaced two to four times a year by a reserve set. There are two races of Western Diamondback Rattlesnake found in Canada. One is the Prairie Rattler, found in Alberta and Saskatchewan and the other the Northern Pacific Rattler, found in arid valleys throughout British Columbia. The Prairie Rattler is the lighter in hue of the two species.

Both are known as pit vipers because of the pit organ found between the snake’s nostrils and eyes. The pit organ, also known as the Jacobson’s organ, detects temperature differences between the interior temperature of the snake’s body and the outside surrounding temperature which assists the snake to find its prey to a temperature difference of less than .5 of a degree. The pit organ is located on the top of the snake’s mouth. The Western Diamondback Rattlesnake is a cold-blooded reptile because their internal temperature changes according to their outside surroundings. The Western Diamondback Rattlesnake has to rely on the heat generated by the sun to heat its body which functions best at a temperature of 86 degrees Fahrenheit, (30 degrees Celsius) enabling the snake to move and digest its food easier. At colder temperatures, the major
organs of the snake may stop working properly which could lead to death.