In the 1940s, the brown tree snake reached Guam hidden in post-WWII cargo and set off a chain reaction that scientists are still measuring today; birds gone, tree seedlings down by up to 92%, and spiders multiplying up to 40-fold on an island that once had neither

When people think about the damage an invasive predator can do, they mostly think about the animals it directly kills. What they rarely consider is what becomes of the trees.

A study titled ‘Effects of an invasive predator cascade to plants via mutualism disruption’ by researcher Haldre S. Rogers and colleagues at Iowa State University and the University of Washington, published in Nature Communications, shows that one invasive snake on a tiny Pacific island has started a cascade so devastating that the forest itself may be losing its ability to regenerate. The brown treesnake is to blame. The victim, ultimately, is the island of Guam.