Brazil’s Snake Island: A venomous, off-limits haven for researchers

Ilha da Queimada Grande off Brazil hosts thousands of golden lancehead vipers on 43 hectares, making it one of the world’s deadliest wildlife sites. Access is restricted to scientists and the military; bites to humans are rare because the venom targets birds. The species is listed as Critically Endangered by the IUCN, with an estimated 2,000–4,000 snakes, and illegal pet trade contributes to its decline, with snakes selling for up to $30,000.