Ilha da Queimada Grande (Snake Island)

Ilha da Queimada Grande, often called Snake Island, is a small island in the Atlantic Ocean about 33 km off the coast of Sao Paulo state, Brazil. It covers about 43 hectares, and its land ranges from bare rock to rainforest. It is the only natural home of the golden lancehead, a highly venomous pit viper that eats birds.

The snakes were trapped on the island thousands of years ago, when rising seas at the end of the last ice age cut it off from the mainland. Over time they adapted and their numbers grew. The island is closed to the public to protect both people and the snakes. Only the Brazilian Navy and approved researchers may go there.

Why so many snakes?

Without the mainland's usual predators and prey, the golden lancehead evolved to fit island life. It hunts birds that rest on the island. The island was once thought to hold about 430,000 snakes, but recent estimates are much lower, and the exact number is uncertain. The golden lancehead is critically endangered, so protecting it matters. Its survival depends on the island staying undisturbed.

Name and history

'Queimada' means 'burned' in Portuguese. The name comes from local attempts to clear land for banana plantations by setting fires. A lighthouse was built in 1909 to guide ships away, and the last people left when it became automatic in the 1920s. Since 1985 the island and a neighbouring one have been protected as an area of ecological interest. The ban on visitors helps both sides.

On the globe

Look for the Atlantic Ocean off the coast of Sao Paulo state, southeastern Brazil.