His study subject, the Jararaca lance snake, is particularly common in south-eastern Brazil. This snake is the cause of most snakebites in the region and accounts for a significant proportion of incidents in the country, with a total of around 20,000 envenomations per year. It is therefore one of the most relevant venomous snakes - although its bite is rarely fatal.
Alves-Nunes from the Butantan Research Center in Sao Paulo therefore wanted to investigate which factors cause the otters to bite - the behavior of reptiles is a generally neglected field of research, especially in Brazil, explained Alves-Nunes in an interview with the journal "Science". "If you study malaria, you can study the virus that causes the disease - but if you don't study the mosquito that transmits it, you will never solve the problem," he said.
"I tested 116 animals and stepped on each one 30 times." During the test series, which lasted several days, he stepped on and next to the snakes a total of 40,480 times. The animals were placed individually in an arena measuring around two square meters at different times of the day over a longer period of time. After a 15-minute acclimatization phase, the biologist wearing safety boots stepped randomly either directly next to the snake or gently on the head, the middle of the body or the tail.
Long hospital stay after snake bite
He felt 100 percent safe, none of the bites penetrated the foam-covered boots. He was only bitten during a simulation with a rattlesnake. "Unfortunately, I discovered that I am allergic to both the antivenom and snake toxins," he said. That's why he had to spend a long time in hospital.
Here, the young scientist at the Butantan research center poses with a snake on Instagram:
Young females particularly keen to bite in the heat
The result of the study: the smaller a jararaca viper is, the more likely it is to bite. "In addition, the females are more aggressive and more likely to bite, especially when they are young and during the day." The study also shows that females are more likely to bite at higher temperatures, but males are less likely to bite at night - they then prefer to flee with their well-heated bodies. In addition, the probability of a defensive bite is much higher if you touch a snake on the head than if you step on the middle of the body or the tail.
Study to help distribute antivenom better
The researchers hope that the results will improve the distribution of antivenoms. These are often sent to larger hospitals, for which some patients have to travel far because they have been bitten in places where there is no antivenom. "By combining our data with data from other studies on the distribution of snakes, we can identify the places where the animals are more likely to be aggressive," explained Alves-Nunes. "For example, warmer locations with a higher proportion of female snakes should be prioritized for antivenom distribution."