Western Diamondback Rattlesnake

Western Diamondback Rattlesnake

Western diamond-backed rattlesnake, Texas diamond-back, Adobe snake, Arizona diamond rattlesnake, coon tail

Kingdom
Phylum
Subphylum
Class
Order
Suborder
Family
Genus
SPECIES
Crotalus atrox
Population size
Unknown
Life Span
15-20 years
Weight
1-2.7
2.2-5.9
kglbs
kg lbs 
Length
120
47
cminch
cm inch 

The Western diamondback rattlesnake (Crotalus atrox) is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S.

No

Nocturnal

Di

Diurnal

Ca

Carnivore

Sc

Scavenger

Te

Terrestrial

Am

Ambush predator

Pr

Precocial

Ov

Oviparous

Bu

Burrowing

Br

Brumation

Ve

Venomous

So

Solitary

No

Not a migrant

W

starts with

Appearance

The color pattern of these snakes generally consists of the dusty-looking gray-brown ground color, but it may also be pinkish-brown, brick red, yellowish, pinkish, or chalky white. This ground color is overlaid dorsally with a series of dorsal body blotches that are dark gray-brown to brown in color. Some of the first few blotches may be somewhat rectangular, but then become more hexagonal and eventually take on a distinctive diamond shape, hence the name "diamondback rattlesnake". The tail has two to eight black bands separated by ash-white or pale gray interspaces; this led to the nickname "coon tail".

Video

Distribution

Geography

Western diamondback rattlesnakes are found in the United States from central Arkansas to southeastern and Central California, south into Mexico as far as northern Sinaloa, Hidalgo, and northern Veracruz. In the United States, they occur in central and western Arkansas, Oklahoma, Texas, southern and central New Mexico and Arizona, extreme southern Nevada, southwestern Utah, and southeastern California on either side of the Chocolate Mountains. In Mexico, they occur in Nuevo León, Coahuila, Chihuahua, Sonora, extreme northeastern Baja California, northern Sinaloa, northeastern Durango, Zacatecas, most of San Luis Potosí, northern Veracruz, Hidalgo, and Querétaro. These snakes have also been reported on a number of islands in the Gulf of California, including San Pedro Mártir, Santa María (Sinaloa), Tíburon, and the Turner Islands. Western diamondback rattlesnakes live in different habitats that range from flat coastal plains to steep rocky canyons and hillsides; they can be found in the desert, sandy creosote areas, mesquite grassland, desert scrub, open pine forest, and pine-oak forests.

Western Diamondback Rattlesnake habitat map

Climate zones

Western Diamondback Rattlesnake habitat map
Western Diamondback Rattlesnake
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Habits and Lifestyle

Western diamondback rattlesnakes are solitary creatures. Usually inactive between late October and early March, these snakes occasionally may be seen basking in the sun on warm winter days. They can be active at any time of the day or night when conditions are favorable. They are primarily diurnal and crepuscular in spring and fall and become nocturnal and crepuscular during the hot summer months. These snakes hunt mainly at night or in the early morning. In the winter, they hibernate or brumate in caves or burrows, sometimes with many other species of snakes. Western diamondbacks are poor climbers. When threatened, they usually coil and rattle to warn aggressors. They are one of the more aggressive rattlesnake species in the US in the way that they stand their ground when confronted by a foe. If rattling does not work, then the snake will strike in defense.

Seasonal behavior

Venom

Like most other American pit vipers, the venom contains proteolytic enzymes. The venom of this species is primarily hemotoxic, affecting mainly the blood vessels, blood cells, and the heart. The venom contains hemorrhagic components called zinc metalloproteinases. The venom also contains cytotoxins and myotoxins which destroy cells and muscles, adding to the damage to the cardiovascular system. In addition to hemorrhage, venom metalloproteinases induce myonecrosis (skeletal muscle damage), which seems to be secondary to the ischemia that ensues in muscle tissue as a consequence of bleeding and reduced perfusion. Microvascular disruption by metalloproteinases also impairs skeletal muscle regeneration, being thereby responsible for fibrosis and permanent tissue loss. General local effects include pain, heavy internal bleeding, severe swelling, severe muscle damage, bruising, blistering, and necrosis; systemic effects are variable and not specific but may include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, and convulsions. Bleeding caused by hemorrhagins is a major clinical effect that can be fatal. Because of its large venom glands and specialized fangs, the Western diamondback rattlesnake can deliver a large amount of venom in a single bite. The average venom yield per bite is usually between 250 and 350 mg, with a maximum of 700-800 mg. Severe envenomation is rare but possible and can be lethal. The mortality rate of untreated bites is between 10 and 20%.

Diet and Nutrition

Western diamondback rattlesnakes are carnivores and they are one of the few species of snakes that engage in scavenging behavior. They feed on small mammals such as chipmunks, prairie dogs, voles, woodrats, rabbits, ground squirrels, and also birds, lizards, and even fish.

Mating Habits

REPRODUCTION SEASON
fall
PREGNANCY DURATION
6-7 months
BABY CARRYING
10-25 young
INDEPENDENT AGE
at birth
FEMALE NAME
female
MALE NAME
male
BABY NAME
snakelet
web.animal_clutch_size
10-25 young

Western diamondback rattlesnakes usually mate during the fall. They are viviparous meaning that females give birth to live young. Gestation lasts 6 or 7 months and broods average 10 to 25 young. The snakelets are fully-developed and capable of delivering a venomous bite from the moment they are born. They stay with the mother for only a few hours before they set off on their own to hunt and find cover. Western diamondbacks become reproductively mature when they are 3 years old.

Population

Population threats

There are no major threats to Western diamondback rattlesnakes. However, they do suffer locally from habitat destruction and roadkill. They are also heavily collected from the wild, frequently being drawn out of their hiding places with gasoline and used in rattlesnake roundups (rattlesnake rodeos), where they are killed for food, skins, and entertainment.

Population number

According to IUCN, the Western diamondback rattlesnake is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers are stable.

Ecological niche

Key participants in the food chain, Western diamondbacks are important predators of many small rodents, rabbits, and birds. In turn, they are preyed upon by a variety of larger mammals and birds, such as coyotes, foxes, hawks, and owls.

Fun Facts for Kids

  • Other common names of these snakes include desert diamond-back, desert diamond rattlesnake, fierce rattlesnake, spitting rattlesnake, buzz tail, Texan rattlesnake, Texas diamond-back, and Texas rattler.
  • Western diamondbacks can go for up to two years without food in the wild.
  • These snakes can move their rattle back and forth 60 times per second.
  • The rattle of Western diamondbacks is made up of keratin. It is the same protein that human nails and hair are made of.
  • A group of rattlesnakes is usually called rhumba.

Coloring Pages

References

1. Western Diamondback Rattlesnake on Wikipedia - https://en.wikipedia.org/wiki/Western_diamondback_rattlesnake
2. Western Diamondback Rattlesnake on The IUCN Red List site - https://www.iucnredlist.org/species/64311/12763519

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