Attention arachnophobes and friends of Indiana Jones, this will totally creep you out.
A recent study reveals that the jungles of Guam have been overrun by spiders, with 40 times the population of nearby Pacific islands. This whopper of a web count seems to be the direct result of human intervention in the natural top-down balance of Guam’s ecosystem with the introduction of the brown tree snake in the 1940s. The bird-munching, uninvited invader, whose predator-free population exploded over the decades, has so dramatically reduced avian populations in the jungles that the number of spiders—and their insect diet—is burgeoning.
Despite costly efforts to eradicate the slithering predator, the snakes, and therefore the spiders, continue multiplying. Though man-made food-chain disruption has been experienced in small-scale experiments, the spider boom on Guam is a monstrous real-life manifestation to be filed under ecological cautionary tale.