Snake FinderField Guide · Worldwide

Rattlesnake

Sinaloan Long-tailed Rattlesnake

Venomous

Crotalus stejnegeri

Sinaloan Long-tailed Rattlesnake
Crotalus stejnegeri, Patrick Campbell / Wikimedia Commons

The Sinaloan Long-tailed Rattlesnake (Crotalus stejnegeri) is a venomous snake in the Viperidae family, recorded in 1 country.

If you are bitten

Rattlesnake bites are medically serious. Expect intense pain, rapid swelling, and bruising. Stay calm, keep the bitten limb still and roughly level with the heart, remove rings and tight clothing, and get to an emergency room immediately. Do NOT apply a tourniquet, cut the wound, apply ice, or try to suck out venom. Call Poison Control at 1-800-222-1222 or 911 in the US, or your local emergency number. (Source: CDC.)

Also called
Rattlesnake
Family
Viperidae
Size
Typically 2–5 ft; some species exceed 6 ft.
Habitat
Deserts, rocky outcrops, grasslands, and woodland edges, depending on species.
Behavior
Ambush predators that buzz the tail as a warning; mostly active in warm months and often crepuscular in summer heat.
Identify
Heavy body, broad triangular head, vertical (cat-like) pupils, and a segmented keratin rattle at the tail tip.
Danger
high

About the Sinaloan Long-tailed Rattlesnake

Crotalus stejnegeri, commonly known as the Sinaloan long-tailed rattlesnake or just long-tailed rattlesnake, is a venomous pit viper species in the family Viperidae. The species is native to western Mexico. There are no recognized subspecies.

Etymology

The specific name, stejnegeri, is in honor of Leonhard Stejneger, herpetologist at the Smithsonian Institution for over 60 years.

Description

Adults of C. stejnegeri do not usually grow to more than 60 cm (24 in) in total length (including tail). The greatest total length recorded for a specimen is 72.4 cm (28.5 in). The tail is relatively long, representing 11.0-14.8% of the total length of adult male snakes and 9.8-12.5% in females. Klauber (1940) suggested that since the rattle is tiny, it is probably not audible. A very rare species, there have only been 12 specimens found.

Geographic range and habitat

C. stejnegeri is found in western Mexico in the mountains and foothills of eastern Sinaloa, western Durango, and small areas in northern Nayarit, between 500 and 1,200 metres (1,600 and 3,900 ft) in altitude. The type locality given is "Plumosas [Plomosas], Sinaloa, Mexico". It occurs in pine-oak forest, subtropical dry forest, and tropical deciduous forest.

Conservation status

C. stejnegeri is classified as Vulnerable on the IUCN Red List of Threatened Species with the following criteria: B1ab(iii) (v3.1, 2001). A species is listed as such when the best available evidence indicates its extent of occurrence is estimated to be less than 20,000 km2 (7,720 mi2), estimates indicate it is severely fragmented or known to exist at no more than 10 locations, and a continuing decline has been observed, inferred, or projected in its area, extent, and/or quality of habitat. Therefore, it is considered to be facing a high risk of extinction in the wild. The population trend was down when assessed in 2007.

Adapted from Wikipedia, available under CC BY-SA.

Frequently asked: Sinaloan Long-tailed Rattlesnake

Is the Sinaloan Long-tailed Rattlesnake venomous?
Yes. The Sinaloan Long-tailed Rattlesnake (Crotalus stejnegeri) is venomous and belongs to the Viperidae family (rattlesnake). Its bite is considered high risk to people. Treat any bite as a medical emergency.
Is the Sinaloan Long-tailed Rattlesnake poisonous?
Snakes are venomous, not poisonous. "Poisonous" means harmful to eat or touch; "venomous" means injecting toxins through a bite. The Sinaloan Long-tailed Rattlesnake is venomous, delivering venom through a bite.
Is the Sinaloan Long-tailed Rattlesnake dangerous?
Rattlesnake bites are medically serious. Expect intense pain, rapid swelling, and bruising. Stay calm, keep the bitten limb still and roughly level with the heart, remove rings and tight clothing, and get to an emergency room immediately. Do NOT apply a tourniquet, cut the wound, apply ice, or try to suck out venom. Call Poison Control at 1-800-222-1222 or 911 in the US, or your local emergency number. (Source: CDC.)
Where does the Sinaloan Long-tailed Rattlesnake live?
The Sinaloan Long-tailed Rattlesnake has verified records in 1 country, including Mexico. See the distribution section below for its full range.
How do I identify the Sinaloan Long-tailed Rattlesnake?
Heavy body, broad triangular head, vertical (cat-like) pupils, and a segmented keratin rattle at the tail tip.
How big does the Sinaloan Long-tailed Rattlesnake get?
Typically 2–5 ft; some species exceed 6 ft.
Why is it called the Sinaloan Long-tailed Rattlesnake?
The specific name, stejnegeri, is in honor of Leonhard Stejneger, herpetologist at the Smithsonian Institution for over 60 years.

If you are bitten by the Sinaloan Long-tailed Rattlesnake

A venomous snakebite is a medical emergency. Call your local emergency number immediately. In the US, dial 911 or Poison Control at 1-800-222-1222.

Do

  • Get away from the snake and stay calm. Most bites worsen when people panic or try again to handle the snake.
  • Call 911 or Poison Control (1-800-222-1222) right away. Antivenom works best when given early.
  • Note the time of the bite and, from a safe distance, the snake's color and pattern, a phone photo is enough. Do not chase it.
  • Keep the bitten limb still and at roughly heart level. Sit or lie down and limit movement.
  • Remove rings, watches, and tight clothing near the bite before swelling starts.
  • Gently wash the bite with soap and water and cover it with a clean, dry dressing.

Do not

  • Do not cut the wound or try to suck out the venom.
  • Do not apply a tourniquet or ice.
  • Do not drink alcohol or caffeine.
  • Do not take aspirin or ibuprofen, they can worsen bleeding. Acetaminophen is safer for pain.
  • Do not try to catch or kill the snake. A dead snake can still bite by reflex.

First-aid guidance adapted from the U.S. Centers for Disease Control and Prevention (CDC NIOSH), Venomous Snakes. Educational only; always follow the instructions of emergency responders.

Where it is found

More Viperidae snakes

Classification

How scientists group this snake, from the broadest category down to the exact species. Each step narrows to its closest relatives.

OrderThe broad group of scaled reptiles: all snakes and lizards
Squamata
FamilyA group of related snakes that share key traits
Viperidae
GenusA close-knit group of very similar species
Crotalus
SpeciesThis exact snake, named in the two-part scientific name
Crotalus stejnegeri

Keep learning

Distribution from GBIF & iNaturalist. Venom status per CDC. Background: Wikipedia. Informational only. Never handle a snake to identify it.