To Scientists' Surprise, Even Nonvenomous Snakes Can Strike at Ridiculous Speeds

When a snake strikes, it literally moves faster than the blink of an eye, whipping its head forward so quickly that it can experience accelerations of more than 20 Gs. Such stats come from studies of how a snake lunges, bites and kills, which have focused mostly on vipers, in part because these snakes rely so heavily on their venomous chomps. Not so fast: When Penning and his colleagues compared strike speeds in three types of snakes, they found that at least one nonvenomous species was just as quick as the vipers. The results hint that serpents' need for speed may be much more widespread than thought, which raises questions about snake evolution and physiology. So the team set out to compare three species: the western cottonmouth and the western diamond-backed rattlesnake, which are both vipers, and the nonvenomous Texas rat snake. They put each snake inside a container and inserted a stuffed glove on the end of a stick. They waved the glove around until the animal struck, recording the whole thing with a high-speed camera. The team tested 14 rat snakes, 6 cottonmouths and 12 rattlesnakes, recording several strikes for each individual. All the snakes turned out to be speed demons, the team reports this week in Biology Letters. The rattlesnake scored the highest measured acceleration, at 279 meters per second squared. But to their surprise, the nonvenomous rat snake came in a close second at 274 meters per second squared. That's lightning-quick, considering that a Formula One race car accelerates at less than 27 meters per second squared to go from 0 to 60 in just one second. "I was really surprised, because this comparison hadn't been made before," Clark says. "It's not that the vipers are slow, it's that this very high-speed striking ability is something that seems common to a lot of snake species—or a wider array than people might've expected."...more