A Brazilian biologist who wanted to know when and why poisonous snakes bite chose an unusual method to investigate the subject: by stepping on or near the dangerous animals tens of thousands of times.
Joao Miguel Alves-Nunes of the Butantan Institute used jararacas – a highly venomous viper found throughout South America and responsible for biting around 20,000 people a year – for his research.
The results of this risky venture in the name of science, which could save lives, were published this month in the journal Nature..
What did the research show?
In an interview with Science magazineAlves-Nunes said there had previously been little research into the factors that cause snakes to bite.
He said his method of treading on or near the animals – in special protective boots – had allowed him to refute the common assumption that jararacas only bite if people touched or stepped on them.
“I stepped close to the snake and also slightly on top of it,” Alves-Nunes said. “I didn’t put all my weight on my foot, so I didn’t hurt the snakes. I tested 116 animals and stepped on each animal 30 times, for a total of 40,480 steps.”
According to Alves-Nunes, the likelihood that a jararaca would bite was inversely proportional to its size. In other words, the smaller the animal, the more likely it is to sink its teeth into someone.
The female of the species is also more aggressive than the male, the study found, especially when young and during the day.
The snakes were also more susceptible to biting during warm weather.
The chance of being bitten also increased if the snakes were touched on their heads rather than the center of their bodies or their heads, the study found.
Useful for deploying antidote supplies
Alves-Nunes said information from the study would help alleviate the problem of snakebites in Brazil.
“With our new findings, we can predict where bites may occur and plan better distribution of antivenom,” he said.
“By combining our data with data from other studies showing snake distribution, we can identify places where the animals are likely to be aggressive. For example, warmer places with larger populations of female snakes should be a priority for antivenom distribution. “
Snake researcher allergic to antivenom
Alves-Nunes said he felt “100% safe” stepping on or around the tubing because of the boots he was wearing, which he said were chosen based on advice from experienced colleagues at the institute.
However, although the jararacas failed to pierce the boots, he was bitten while experimenting with a rattlesnake and required hospital treatment.
“Luckily I was in the best place I could be,” he said, adding that the Butantan Institute was a leader in antivenom development.
But the bite did reveal an unfortunate trait of a snake researcher.
“Unfortunately, I discovered that I am allergic to both antivenom and snake venom. I had to take a 15-day medical leave,” he said Science.
However, Alves-Nunes once again shows his passion for knowledge at all costs and turns the setback into good scientific justification.
“I’m now comparing the bite force of rattlesnakes and jararacas and how resistant different materials and shoes are to them,” he said.