Reading Test - Snake Island [PDF]

Zitiervorschau

Reading test 3

Snake Island The mysterious island, Ilha da Queimada Grande otherwise known as Snake Island, situated about 25 miles off the coast of Brazil, is so dangerous it has been made illegal for anyone to visit. The reason, as the name suggests, is snakes. It estimated that there is about one deadly snake per square foot there. The dangerous snake that is found on Ilha da Queimada Grande is the golden lancehead snake – a species of pit viper and one of the deadliest snakes in the world; they are so venomous that a human bitten by one could be dead within an hour. The golden lancehead can grow to be over a foot-and-a-half long and it is estimated that there are between 2,000 and 4,000 golden lancehead snakes on the island. The golden lancehead’s mainland cousins, lancehead snakes are responsible for 90 percent of all snake bites in Brazil. While their bite is less venomous than their golden relatives a person unlucky enough to be bitten by a regular lancehead still faces a seven percent chance of death if untreated. It is thought that the golden lancehead evolved differently from those on the mainland because the only prey the island snakes had were birds. It is thought they evolved to have particularly potent venom as they needed to kill any bird they attacked quickly and efficiently. Golden lanceheads rely on birds who visit the island to rest as their food source. Perhaps as we could expect of such a mysterious and dangerous place, many myths exist about Ilha da Queimada Grande. One story says that the snakes were originally introduced to the island by pirates because they wanted to protect treasure they had buried on the island. In fact, the scientific truth is that Snake Island used to be part of Brazil’s mainland, but when sea levels rose over 10,000 years ago, it separated the landmass and turned it into an island isolating the snakes already living on the part of the land from which the island was formed. Snake Island has been uninhabited since the 1920s, though visits by the navy are carried out periodically to check the condition of a lighthouse situated there and to make sure that explorers are not wandering too close to the island. One reason that certain people may take the risky decision to visit the island illegally is to make money. The golden lancehead’s venom can be used in medicine as a lifesaving drug that can be an effective treatment for heart problems and high blood pressure. Because of its medicinal properties, there is a very profitable black-market demand for venom.