Which Island Has the Highest Concentration of Venomous Snakes?

Nearly a third of adults have an intense fear of snakes, a condition technically known as ophidiophobia. If you're one of them, then the last place you would want to visit is the Brazilian island of Ilha da Queimada Grande, located about 90 miles (145 km) south of downtown São Paulo. Nicknamed "Snake Island," this spit of land off the South American coast in the Atlantic Ocean is off-limits to humans because it’s home to thousands of golden lancehead vipers, one of the world’s most deadly snakes -- and also one of the most rare. Researchers estimate that there are as many as five snakes per square meter (around 11 square feet) on the island.

No island paradise:

• The Brazilian government controls visits to Ilha da Queimada Grande. A doctor must be present for anyone granted special permission to visit the island, such as biologists and researchers.
• Venom from a golden lancehead can kill a person in less than an hour. The venom can lead to kidney failure, necrosis of muscular tissue, brain hemorrhage, and intestinal bleeding.
• The endangered snakes survive on seasonal migratory birds that stop there to rest. The golden lancehead’s venom is nearly five times stronger than any other snake, and bitten birds die almost instantly.

Frequently Asked Questions

Which island is known for having the highest concentration of venomous snakes?

Ilha da Queimada Grande, also known as Snake Island, off the coast of Brazil, holds the title for the highest concentration of venomous snakes. The island is home to a dense population of the highly venomous golden lancehead pit viper, with estimates suggesting there's approximately one snake per square meter in some areas.

Are humans allowed to visit Snake Island?

Access to Snake Island is strictly controlled by the Brazilian government due to the extreme danger posed by the golden lancehead snakes and the need to protect their habitat. Only select researchers and the Brazilian Navy are typically granted access, making it off-limits to tourists and the general public.

What makes the golden lancehead snakes on Snake Island so dangerous?

The golden lancehead viper's venom is highly potent, adapted to quickly immobilize birds, their primary prey. According to studies, their venom is fast-acting and can cause kidney failure, necrosis of muscular tissue, and even death if a human is bitten and not treated promptly with appropriate medical care.

How did Snake Island become so densely populated with venomous snakes?

Snake Island became a haven for the golden lancehead vipers after rising sea levels cut off the island from the mainland, eliminating natural predators. This isolation allowed the snakes to thrive and multiply, leading to the high density of snakes currently found on the island.

What efforts are being made to conserve the golden lancehead population on Snake Island?

Conservation efforts for the golden lancehead vipers include strict regulations on human access to protect both the snakes and potential human visitors. Research initiatives aim to understand the ecology of the snakes better and ensure their survival, as the species is classified as critically endangered due to its limited habitat range and declining numbers.

Can the venom of the golden lancehead viper be used for medical purposes?

Yes, the venom of the golden lancehead viper has been the subject of medical research due to its unique properties. Scientists are investigating the potential of its venom in developing new medications, particularly for conditions that affect the circulatory system, as some components of the venom have shown promise in aiding blood clotting and circulation.