Alien Snakes Help Spiders Overrun Guam
by OurAmazingPlanet staff
The jungles of Guam have up to 40 times more spiders than do the forested areas of nearby Pacific islands thanks in part to the brown tree snake, according to a study published this week in the journal PLoS One.
The bird-devouring snake from northern Australia and nearby islands was introduced to Guam in the 1940s. The ravenous reptile became the dominant predator; bird numbers plummeted. By the 1980s, 10 of 12 native bird species had been wiped out, and the last two survive only in small areas, protected by intense snake-trapping.
Small-scale experiments show that areas without birds have more spiders – which makes sense, because birds eat spiders and the insects upon which spiders feed. But the sheer numbers of spiders found in Guam’s jungles were much greater than predicted by these small studies, suggesting the removal of birds from an entire forest can have unforeseen — and creepy — effects…
(read more: Live Science) (photos: Isaac Chellman)
