Ridge-nosed rattlesnakes (Crotalus willardi) are members of the genus Crotalus, which includes about 25 species of North American rattlesnakes, some of which are among the most deadly snakes in the world. These medium-sized pit vipers are native to arid and rocky regions of New Mexico, Arizona, Texas, and Mexico’s Chihuahua state. They don’t often bite people, but they can deliver a nasty bite if they do, so care must be taken to keep them as pets.
Ridge-Nosed Rattlesnakes (Crotalus willardi)
The Ridge-Nosed Rattlesnake has a scientific name which describes its physical appearance quite well. The species name willardi is in honor of physician, naturalist, explorer, ichthyologist, herpetologist, geologist and curator at Field Museum of Natural History Dr. William D. Willard (1867–1937).
This descriptive common name for what is now known as Crotalus willardi was given to them by Dr. John Van Denburgh in his 1909 publication The Reptiles of Western North America. There are two subspecies of C. willardi: C. w. willardi (Arizona) and C. w. helleri (New Mexico).
They are found throughout much of New Mexico, Arizona, Utah, Colorado and Texas on rangeland grasslands, plains, desert scrubland and sandy hillsides with sparse vegetation where they feed on lizards and small mammals such as ground squirrels or prairie dogs.
These snakes grow to be between 36 – 60 long. Most adults average around 48 – 54 long. These rattlers are not very aggressive but will defend themselves if provoked. These snakes can strike their prey from 2/3 of their body length away! Their venom is hemotoxic and causes bleeding problems that lead to death from internal hemorrhaging or shock if medical treatment isn’t sought-immediately after being bitten by one of these serpents.
Range of the North American Ridge-Nosed Snake
The North American Ridge-Nosed snake can be found in throughout Texas, New Mexico, Arizona, Utah, Colorado and Nevada. The geographic area of their range extends north to southwestern Canada, south into northwestern Mexico. It is also known as horned rattlesnake, horny rattler or smooth scaled rattler.
Its scientific name is Crotalus willardi. This species has two subspecies; Crotalus willardi willardi (Texas) and Crotalus willardi obscurus (New Mexico). These snakes are distributed in rocky areas, semiarid shrublands, grasslands, juniper woodlands, desertscrub and pine forests.
They are most commonly found in foothills, valleys and mountain slopes with rock outcroppings. However they have been spotted at elevations up to 6500 feet above sea level. This species hibernates during winter months by burrowing underground or taking shelter inside crevices within rocks, caves or abandoned burrows made by other animals such as coyotes, foxes and skunks.
Average Size and Weight
The ridge-nosed rattlesnake is on average about 45 in (1.1 m) in length, though it can reach a maximum of 54 inches (137 cm). The typical weight is 5 pounds (2.3 kg), but some specimens have been found to weigh over 7 pounds (3.2 kg). It has an average diameter of 1 inch (2.5 cm).
It has a long body with small eyes and short legs. Its tail is notched near its end, which helps with balance when moving through brush or trees. Its scales are keeled and overlapping. Its coloration is generally grayish brown or reddish brown, but juveniles may be darker in color than adults.
There are two distinct black lines that run down each side of its body from head to tail. There are also two dark lines that run along each side of its head from snout to eye level. These lines are more pronounced in males than females.
Appearance / Coloration
There are thirteen different subspecies of Crotalus willardi, all of which have a coloration pattern that is either brown or tan, with darker brown/black blotches. The only exception to these patterns is C. w. vossorum, which is uniformly light colored except for a dark line that runs down each side of its body. In addition to their base colors, many specimens also have black markings on their dorsal scales and tails.
The average length of these snakes ranges from thirty inches (75 cm) to forty-six inches (110 cm), although some individuals can grow up to fifty-seven inches (145 cm). They also possess an average weight range between 1.3 pounds (.6 kg) and 3 pounds (.9 kg). Their heads are large in comparison to their bodies, but they do not possess any sort of neck rattle.
Breeding occurs mid-spring to early summer. Females lay 2 to 5 eggs in June, which incubate for 3 months. Hatchlings emerge from September to October, with a peak in September. Young are 20–30 cm (8–12 in) at birth; sexual maturity is reached at two years for males and three for females, although breeding does not usually occur until 3–4 years of age.
Females may live 10–15 years or more. Males have shorter lifespans due to their tendency to engage in risky behavior during mating season. They will often fight each other using their venomous bites as weapons, leading to death by either venom or blood loss.
The ridge-nosed rattlesnake, Crotalus willardi, can reach 4 to 5 feet in length. Color is brownish or reddish with crossbands of darker pigment across their bodies. Their scales are keeled (ridged), which gives them a rough texture when touched. Their tail rattles resemble dried leaves when shaken.
These snakes are very secretive, often hiding under rocks and logs during daylight hours. If threatened they will strike repeatedly until danger has passed. They feed on small mammals such as mice and voles. These snakes hibernate from October through March.
The Ridge-Nosed Rattlesnake belongs to a family of snakes known as pit vipers because they have special heat sensing pits between their nostrils and eyes that allow them to detect warm blooded prey in total darkness.
Behavior / Temperament
Despite its name, Lesser Antillean Sistrurus (Sistrurus) is a species of rattlesnake found in Puerto Rico. It is also commonly referred to as a Puerto Rican True Coral Snake or a Lesser Antillean Coralsnake. The subspecies was previously described as Coniophanes fonsecai, but has recently been reclassified as part of Sistrurus catenatus.
As such, it is now recognized as a Ridge-Nosed Rattlesnake. This snake can be identified by its red body with black bands that are edged with yellow scales; however, unlike most other snakes which have heat sensing pits between their eyes and nostrils, it only has one pit on each side of its head near its nostril. Its tail is not very long compared to other snakes; typically measuring less than half of the length of its body.
At around 5 feet in length, an adult ridge-nosed rattlesnake requires a large cage to call home. Buy or construct a snake cage of at least 55 gallons (210 L) for a single specimen, or about 100 gallons (375 L) for a pair. Choose wood as your primary material, since glass or plexiglass cages aren’t usually big enough.
Also make sure your enclosure is escape proof, with a heavy locking door that locks from both sides. It should have a secure screen top to prevent any unwanted visitors from dropping by unannounced.
No matter what type of cage you choose, it should have Â3⁄4 (2 cm) wooden shelves on two opposite walls; Â1⁄4 (6 mm) wire mesh on all other walls; flooring made of non-abrasive materials such as linoleum or tile; adequate ventilation to prevent buildup of toxic fumes, and hide boxes made out of bark chips or similar materials.
While some may find it easier to keep their snake in a glass tank or fish tank, there are several advantages to using an aquarium as your rattlesnake’s home. Aquariums are usually cheaper than glass tanks, can be easily moved should you need to relocate your snake, and allow for better airflow (especially if you use screen covers).
The downside is that snakes are escape artists, so some type of enclosure is needed on top of or along one side of your aquarium. We recommend building a wooden box with a screening on all sides except one, which will face inside your tank. This way, you have easy access to clean out any waste from within your enclosure without worrying about your snake escaping.
Enclosure Furnishings: Substrate Types
Of course, there are many substrates to choose from that can be used to line your enclosure. Some people prefer to keep their rattlers in damp (not soaked) paper towels because they find it easier than keeping an entire enclosure moist. Although paper towels are convenient, they don’t have any nutritional value for your snake; you’ll need a water bowl in order to make sure that your pet is getting enough fluids.
If you do use paper towels, be sure to change them frequently so that they don’t become soiled or moldy. You should also include some hides in your enclosure—your rattler will appreciate having somewhere safe to hide when he wants some privacy! Substrate Choices: Shredded Aspen Shredded aspen bedding is one of the most popular choices among reptile owners due to its affordability and ease of use.
Temperature, Heating, and Humidity Control
Of all of your animal’s basic needs, the temperature is perhaps the most critical. This snake will do best in temperatures of 74 to 84 degrees F with a basking area that is 88 to 90 degrees F. Because some areas of your cage will be hotter than others, offering hiding spots or burrows that are cooler than these basking areas can help assure your snake is not being kept too hot by certain spots within its enclosure.
The ideal humidity level for your Ridge-Nosed Rattlesnake is 40 to 60 percent. The cage should be misted lightly every day but make sure there are no standing water puddles inside it as they may cause respiratory infections and other health problems for your pet.
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