The island of Queimada Grande is one of the most dangerous places in the world for humans. In question, a colony of extremely poisonous snakes, vipers called Golden Lancehead.
Ilha da Queimada Grande, nicknamed Snake Island, “the island of snakes”, is an island of 430,000 square meters located about 33 km off the coast of the state of São Paulo, Brazil. The island is home to a variety of snakes including an endemic species called Golden Lancehead
( Golden Lancehead )which is one of the most poisonous snakes in the world. It is also called the Golden Spearhead Viper.
According to a 2015 estimate, there are between two and four thousand snakes on the island, which equates to an average of one snake per 75 square meters across the island. A Discovery Channel documentary claimed that in some places on the island there is one snake per square meter, while a local legend claims there are five snakes per square meter. Local folklore is also well nourished by stories of horrible deaths suffered by those who had ventured on the shores, in particular that of a fisherman who landed on the island in search of bananas or that of a family of a lighthouse keeper who lived there. Snakes have also taken up residence in this former lighthouse.
Officially, there has never been any report indicating that a human has been bitten by the viper Golden Lancehead.
So that the toxicity of its venom on humans could not be tested. Vipers of the genus Bothrops (those found on the continent, therefore) are responsible for more human deaths than any other known group of snakes in North or South America. A Golden Lancehead
bite results in death in 7% of cases and even with treatment the victim has a 3% risk of dying. Death usually results from intestinal bleeding, kidney failure, brain bleeding, or necrosis of muscle tissue. The venom melts the flesh, and the cell tissue makes it easier for the snake to digest them. Tests have shown that the venom of the viper Golden Lancehead.
is the fastest-acting in the genus Bothrops.
A venom that has become extremely powerful
The snakes on Queimada Grande were originally the same species as those on the mainland, when the island was still connected to the mainland. About 11,000 years ago, when sea levels rose, Queimada Grande and its snake population were isolated from the Brazilian coast. With no small mammals to hunt, snakes have adapted to island life, and managed to climb into the treetops to find their main source of food: the birds that came to rest on the island during their migration.
The inhabitants of the island, who knew how to reproduce in mass, learned to climb trees, and to hunt birds which rest on the branches. It is said that the viper’s venom is five times more potent than that of its continental cousins. Snakes attack their prey by biting them and then patiently wait for the venom to take effect. The problem with birds is that they can fly away while the poison takes effect. Thus, the venom of the Golden Lancehead.
evolved to become extremely potent. When there are no migrating birds to eat, snakes are content with lizards, centipedes, slugs and frogs.
A forbidden island
The island is currently closed to humans, and the Brazilian government strictly controls who visits the island and when. Visitors are mostly biologists and researchers, who have been granted special permission to travel to the island to study Bothrops insularis. The Brazilian Navy makes an annual stop on the island for maintenance of the lighthouse, which since the 1920s has been automated. Moreover, in 2014, VICE journalists accompanied the Brazilian navy to make a documentary on the island, which provides images of what the island really looks like:
Due to black-market demand by scientists and animal collectors, traffickers known as “biopirates” have also visited Queimada Grande Island. They trap the snakes and sell them through illegal channels. A single Golden Lancehead
The viper can sell for between $10,000 and $30,000.
Habitat degradation, due in particular to the removal of vegetation by the Brazilian Navy and disease, are affecting the island’s population, which has declined by nearly 50% in the past 15 years, according to some estimates. The snake is currently highly threatened with extinction by the International Union for the Conservation of Nature (IUCN). While this may make Snake Island slightly less terrifying for humans, it is still bad news for this endemic wildlife.