The science of snake bite

High-speed cameras take the rattlesnake attack out of the laboratory and into the natural world

Rattlesnakes are not difficult to find in the New Mexico desert. Sit down to drink a glass of water, and you'll likely hear a rustle behind a rock. That's why Timothy Higham of the University of California, Riverside and Rolon Clark of San Diego State University went there to search for the snake in the summer of 2015. The researchers traveled to the desert with a crew of ten students, postdoctoral researchers and volunteers transporting the snake. Eight cars. Batteries, chairs, computers and other equipment in the bush to take photos of Mojave rattlesnakes.

Why all the fuss over a few snake videos? While researchers have been able to use high-speed cameras to record and analyze rattlesnakes and other snakes striking their prey in the laboratory, biologists have never been able to capture snake feeding attacks under natural conditions. “We realized that laboratory research on snakes could be artificial because we were making them hit artificial targets in an artificial environment,” Higham says. “With modern technological advances, we can record snakes in the wild and see what this reveals about predator-prey interactions in general.”

In the past, Higham says high-speed cameras were not usable in the field. Most were large and designed for controlled environments such as laboratories and crash testing facilities. But over the past decade, cameras have declined. A new high-speed camera, sealed to keep desert sand out, and capable of capturing infrared light, made this new research possible, Higham says.

Although the camera was at the heart of the search, other factors came together to spot the snakes. Clark, for example, is an expert at tagging and tracking snakes. This allowed the crew to identify rattlesnakes during the day and move them at night when they curled up in attack mode, waiting for their prey to lunge. That's where all the batteries came in: The crew set up infrared lights to illuminate the snake and focused the camera on it. Then they sat and waited, hoping to pounce on Miriam's kangaroo rat, dipodomys mereami, On video.

Some nights, Higham, Clark and their team waited 10 hours and saw nothing. Ultimately, over the course of the field season, they were able to record eight rattlesnake strikes, four of which were successful, and four of which were puffs (they detailed their findings in the journal Scientific reports). By slowing down the video from 500 frames per second to about 5% of normal speed, the researchers were able to analyze exactly how the snake struck the mouse, and what evasive maneuvers the small mammal made to avoid being eaten. Although Higham says they didn't score as many hits as he had hoped, even the errors provided valuable data. “It turns out that the reasons why the snake succeeded or failed were very variable, and that's something we would never observe in the laboratory,” he says. “Sometimes the snake may have made a mistake. Sometimes the kangaroo rat did not see the snake. In these conditions both predator and prey co-evolve. It is therefore absolutely necessary to observe animals in their natural habitat before drawing too many conclusions from laboratory studies alone.”

The research also suggested something else that laboratory research has been missing: snakes in their natural habitat attack more quickly than animals recorded in laboratories. Although this finding is not particularly surprising, David Benning, a biologist at Missouri Southern State University who recently conducted research debunking the scientific myth that snakes have the fastest typing among snakes, says the new method of research could revolutionize Herpetology and herpetology. “In terms of what's going on at Higham, it's way ahead of the curve when it comes to field research,” Benning says. “It's labor intensive, but they have a nice model to study snakes that sit in one place and wait for their food.”

Benning hopes this is just the first of many similar studies. “There is a lot of research to be done,” he says. “Out of the 3,500 species of snakes out there, we probably have a strike rate of less than 1%. As technology advances, there are definitely more to come. I mean you can now get 256 frames per second on an iPhone.”

Higham would be happy if one day he could conduct his investigations using only an iPhone, but until then, he plans to continue working with those around him. In the summer of 2016, he conducted a similar study on the Sidewinder rattlesnake. crotalus Cerastus, In Arizona using the same expensive setup and catching 30 hits. He hopes his work will whet the appetite of the public and the research community for these types of images. “We need to understand predator-prey interactions in nature,” he says. “In the next 10 years, I hope there will be a movement to understand this not only in the laboratory, but also in nature. The development of high-speed video technology is increasing so rapidly that I think people will accidentally start capturing predator/prey interactions with special GoPro cameras.” The amount of information we get will be absolutely amazing.