Snakes on a plane – that is how some invasive species may be moving around. A terrifying prospect for travellers and a great way to extend territory for the brown tree snake. These snakes have become one of the most successful invasive species and for some time no one really knew how did that happen. But now a new University of Queensland-led study revealed how ‘hitchhiking’ on planes laid foundation for the brown tree snake dominance.
You don’t have to check under your seat before your next flight – situation is not that extreme, but let’s start with the problem. The brown tree snake has become a huge threat to native bird populations on the island of Guam. These snakes are representatives of invasive species introduced on the Pacific island during World War II. However, unlike with some other invasive species, these snakes were not introduced on purpose. Instead they hitchhiked on troop carriers from the Australian region. That was the beginning, but later one brown tree snakes multiple native bird species into extinction populations on the island of Guam and now are regarded as one of the worst pests of all time.
Scientists decided to see how these snakes managed to spread so far and be so successful as invasive species. They found that the brown tree snake’s venom is 100 times more toxic to birds than to mammals. It is a well-known fact that the brown tree snakes are venomous, but their venom is not dangerous to humans. Now scientists analysed venom of this snake and found that it contains a toxin made up from two other toxins. However, this is not unique feature – any cat-eyed snakes belonging to the same genus would have caused similar devastation. The difference is that the brown tree snake was transported by accident.
In fact, the brown tree snake actually originated in Africa and made its way naturally to Australia. From there they took military planes to Guam. Even though this migration happened during WW2, something similar could still happen today, because military planes are now flying from Guam to Hawaii. Associate Professor Bryan Fry, one of the authors of the study, said: “They have been intercepted in airports in Hawaii in the past, so if these direct flights are allowed to continue, there’s a possibility they could get to Hawaii and wipe out the birds like they did on Guam”.
Of course, understanding how the brown tree snake’s venom works is a good place to start thinking about ways to control the population of this invasive species. Scientists want to develop a smart approach – a simple hunting technique may not work.
Source: University of Queensland