A Brazilian biologist used an unusual method to study the biting behaviour of venomous snakes.
João Miguel Alves-Nunes from the Butantan Research Centre in São Paulo, Brazil lightly kicked Jararaca lance snakes - a widespread and highly venomous viper species in south-eastern Brazil - over 40,000 times using a specially made protective boot.
His findings, published in the journal Scientific Reports, reveal crucial insights into snake bite incidents in the region, which account for a significant portion of the 20,000 poisonings reported annually in Brazil.
The snakes were not harmed during the tests that he conducted with his team from Butantan Research Centre in São Paulo.
Alves-Nunes emphasizes the importance of studying snake behaviour a generally overlooked area of research, especially in Brazil. In most studies, the factors that cause them to bite are not investigated, he says.
"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 notes.
"I tested 116 animals and stepped on each one 30 times." During the series of tests, which lasted several days, he stepped on and next to the snakes a total of 40,480 times.
The Jararaca lancehead snakes (Bothrops jararaca) were individually placed in a 2-square-metre arena at various times of the day. After a 15-minute acclimation period, Alves-Nunes, wearing a safety boot, either stepped next to the snake or gently on its head, body centre or tail.
He reports feeling completely safe, as none of the bites penetrated the foam-covered boots. However, he was bitten once by a rattlesnake and discovered he was allergic to both the antivenom and snake toxins, resulting in prolonged hospitalization.
Key Findings on Snake Biting Behavior
The study found that smaller Jararaca vipers are more likely to bite. Additionally, female snakes are generally more aggressive and prone to biting, especially when young and during the day.
The research also showed that females are more likely to bite at higher temperatures, while males are less likely to bite at night, preferring to flee with their well-warmed bodies.
Furthermore, the likelihood of a defensive bite is significantly higher when a snake is touched on the head compared to the centre of the body or the tail.
Implications for antivenom distribution
The researchers hope their findings will improve the distribution of antivenoms, which are often allocated to larger hospitals, requiring some patients to travel long distances after being bitten.
"By combining our data with other studies on snake distribution, we can identify areas where the snakes are more likely to be aggressive," Alves-Nunes says.
These insights aim to enhance public health responses and ensure that antivenoms are available where they are most needed, potentially saving lives and reducing the burden on healthcare systems.
"For example, warmer locations with a higher proportion of female snakes should be prioritized for antivenom distribution."
