Rattlesnake
Neotropical Rattlesnake
VenomousCrotalus durissus
6 photographs of the Neotropical Rattlesnake. © B. Phalan.
The Neotropical Rattlesnake (Crotalus durissus) is a venomous snake in the Viperidae family, recorded in 23 countries.
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 Neotropical Rattlesnake
Crotalus durissus, known as the South American rattlesnake, tropical rattlesnake, and by other names, is a highly venomous pit viper species found in South America. It is the most widely distributed member of its genus. Currently, seven subspecies are recognized.
Taxonomy
The Guiana rattlesnake, previously recognized as C. d. dryinus, is now considered a synonym for C. d. durissus. In fact, after the previous nominate subspecies for the C. d. durissus complex became the current nominate for Crotalus simus, which now represents its Mexican and Central American members, C. d. dryinus became the new nominate for the South American rattlesnakes as represented by C. durissus. The subspecies previously known as C. d. collilineatus and C. d. cascavella were moved to the synonymy of C. d. terrificus following the publication of a paper by Wüster et al. in 2005.
Subspecies
Table notes:
Description
A large Neotropical rattlesnake, it grows to a length of 1.5 m (4.9 ft), and rarely to a maximum length of 1.9 m (6.2 ft). It has two distinct stripes starting at the base of the head. Within the lines, the color is lighter than the stripes.
The color and pattern of the body are quite variable, most with an 18–32 dorsal with a darker diamond, and rhombic spots, 25–33 (usually 27) rows of dorsal scale in the middle of the body. The head has a dark brown bar at the top, with a dark post-orbital band. The color of the belly varies, it can be white or yellowish, with light gray spots, becoming darker towards the tail. The tail is usually gray, with dark and vague crossed bands.
Behaviour
The species is more active at dusk and in the early hours of the morning; it is highly alert with little warning signs before striking, but like other rattlesnakes they are seldom aggressive towards humans.
Reproduction
The South American rattlesnake has a seasonal reproductive cycle; competition between males (for access to females) begins around the summer's end, with copulation occurring during the fall, and the birth of the young taking place the following spring/summer. Reproduction is ovoviviparous, giving birth to four to eight young. In Roraima, Brazil it has been reported that the gestation lasts for five months, and they are capable of giving birth to up to 14 young.
Diet
The diet consists mainly of rodents, likely due to the great abundance and availability of these animals throughout the year, in most areas where the snakes reside. In some regions, lizards of the Teiidae family are also part of the diet of C. durissus.
Common names
Common names for the species include: South American rattlesnake, tropical rattler, tropical rattlesnake, neotropical rattlesnake, Guiana rattlesnake (previously used for C. d. dryinus). and in Spanish: víbora de cascabel, cascabel, cascabela, and also in Portuguese, cascavel. In Suriname it is known as Sakasneki.
Geographic range
Adapted from Wikipedia, available under CC BY-SA.
Frequently asked: Neotropical Rattlesnake
- Is the Neotropical Rattlesnake venomous?
- Yes. The Neotropical Rattlesnake (Crotalus durissus) 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 Neotropical Rattlesnake poisonous?
- Snakes are venomous, not poisonous. "Poisonous" means harmful to eat or touch; "venomous" means injecting toxins through a bite. The Neotropical Rattlesnake is venomous, delivering venom through a bite.
- Is the Neotropical 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 Neotropical Rattlesnake live?
- The Neotropical Rattlesnake has verified records in 23 countries, including Brazil, Colombia, Argentina. See the distribution section below for its full range.
- How do I identify the Neotropical Rattlesnake?
- Heavy body, broad triangular head, vertical (cat-like) pupils, and a segmented keratin rattle at the tail tip.
- How big does the Neotropical Rattlesnake get?
- Typically 2–5 ft; some species exceed 6 ft.
- What does the Neotropical Rattlesnake eat?
- The diet consists mainly of rodents, likely due to the great abundance and availability of these animals throughout the year, in most areas where the snakes reside. In some regions, lizards of the Teiidae family are also part of the diet of C. durissus.
- Why is it called the Neotropical Rattlesnake?
- Common names for the species include: South American rattlesnake, tropical rattler, tropical rattlesnake, neotropical rattlesnake, Guiana rattlesnake (previously used for C. d. dryinus). and in Spanish: víbora de cascabel, cascabel, cascabela, and also in Portuguese, cascavel. In Suriname it is known as Sakasneki.
If you are bitten by the Neotropical Rattlesnake
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
Snakes it is confused with
Gopher SnakeHarmlessRattlesnakes are sometimes confused with harmless gophersnakes/bullsnakes; only rattlesnakes have a true segmented rattle and a facial pit.
Neotropical Rattlesnake vs Gopher Snake→
More Viperidae snakes
Western RattlesnakeCrotalus oreganus
Western Diamond-backed RattlesnakeCrotalus atrox
Timber RattlesnakeCrotalus horridus
Prairie RattlesnakeCrotalus viridis
Red Diamond RattlesnakeCrotalus ruber
Mojave RattlesnakeCrotalus scutulatus
Western Black-tailed RattlesnakeCrotalus molossus
SidewinderCrotalus cerastes
Classification
How scientists group this snake, from the broadest category down to the exact species. Each step narrows to its closest relatives.
Keep learning
- Are Snakes Dangerous? The Real Risk, in PerspectiveMost snakes are harmless and avoid people. Here is the honest picture of snakebite risk worldwide and how to lower your own.
- Snakebite First Aid: What to Do (and What Never to Do)A clear, CDC-based guide to snakebite first aid: the steps that help, the popular myths that hurt, and how to tell a serious bite from a minor one.
- Venomous vs Nonvenomous: How to Tell the DifferenceThe folk rules for telling venomous snakes apart, where each one fails, and why location-based identification beats guessing by sight.
- What to Do If You Find a SnakeFound a snake at home or on a trail? Here is how to stay calm, give it space, identify it safely, and know when to call a professional.
Distribution from GBIF & iNaturalist. Venom status per CDC. Background: Wikipedia. Informational only. Never handle a snake to identify it.