Rattlesnakes are the subject of countless myths and tall tales; among them is the notion that they strike faster than anything in nature. As is usually the case, the truth is less fantastic. Rattlesnakes are much slower than is commonly supposed. In most cases, humans are capable of much faster movements relatively.
Rectilinear locomotion is the primary method of travel for most rattlesnakes. While traveling in this manner, the rattlesnake will usually lie in a straight line and inch forward by using its ribs much like a caterpillar or millipede would use its legs. Rectilinear motion is not fast, nor is it intended to be. Many large-bodied snakes -- including other pit vipers, boas and pythons -- travel this way because it is energy-efficient.
When a snake moves in a back-and-forth manner across the ground -- seamlessly gripping and pushing of small surface irregularities -- it is called serpentine motion or lateral undulation. This is the fastest form of travel for most snakes, but rattlesnakes don’t engage in this style of locomotion often. Rattlesnake speeds have not been specifically measured, but they likely travel at about 2 to 3 miles per hour in very short bursts. In comparison, the fastest humans can run up to 28 miles per hour. The average human could easily outrun a rattlesnake.
Sidewinding is a method of locomotion in which a snake travels diagonal to the direction he is facing. By throwing a loop of his body diagonally forward, the loop can grip the ground and flip the back and front thirds of the body forward. Though many species will do this for short bursts, sidewinding is best known from the fastest-traveling rattlesnake, the sidewinder (Crotalus cerastes). This method of locomotion is effective on loose substrates and helps snakes to avoid prolonged contact with hot sand. Sidewinders are thought to be able to achieve 3 miles per hour for short bursts, but likely forage at a tenth of that speed.
Though sometimes referred to as the "fastest thing in nature," the strike of a rattlesnake is not as fast as is commonly supposed. Adult prairie rattlesnakes (Crotalus viridis viridis) move about 8 feet per second, according to noted herpetologist Lawrence Klauber in his book "Rattlesnakes: Their Habits, Life Histories and Influence on Mankind, Volume I." This translates to about 5 miles per hour -- much slower than a human's punch, which travels between 15 and 30 miles per hour. Some snakes and individual strikes are slightly faster or slower than this; experimental results have differed slightly depending on the temperatures and the species of rattlesnakes studied. Snakes move faster in warmer temperatures, and western diamondback rattlesnakes (Crotalus atrox) are thought to strike faster than prairie rattlesnakes.
The tail’s speed is greater than the locomotive or strike speed of rattlesnakes. As noted by Brad R. Moon et al. in a 2002 study published in the "Journal of Experimental Biology," tail-shaking speed varies according to species, size and individual; but 50 cycles per second is a reasonable average. Though other snakes vibrate their tails as a defense mechanism, none reach similar rates or have the endurance that rattlesnakes do. To accomplish this, rattlesnakes have evolved specialized tail-shaking muscles.
- Arizona Herpetological Association: Living With Rattlesnakes
- University of Louisiana at Lafayette: Snake Locomotion
- Rattlesnakes: Their Habits, Life History and Influence on Mankind, Volume 1; Lawrence Monroe Klauber
- Animal Diversity Web: Crotalus Cerastes
- The Journal of Experimental Biology: Mechanical Trade-Offs Explain How Performance Increases Without Increasing Cost in Rattlesnake Tailshaker Muscle
- Science Daily: Human Running Speeds of 35 to 40 mph May Be Biologically Possible
- Scientific American: Pro Boxer's Punch Carries Heavy Weight