ESA: Seeds without wings
US military cargo ships from the Admiralty Islands brought the brown tree snake to Guam. It ate 10 forest bird species to extinction; the last two native species are clinging to life.
“What we have is an island with no birds,” says Haldre Rogers of the University of Washington in Seattle. “I found an conservationists nightmare, but an ecologist’s dream.” Rogers was able to imagine a world without birds, “the fate of a silent forest” without birds to eat bugs and disperse seeds.
Looking at seed dispersal, Rogers reckoned that seeds and seedlings would no longer be found far from their parents. And that’s what she found. Without birds to eat seeds and fly to new locations before they drop them or defecate them out, they all just fall—plop—right under their parents.
Without a sudden resurgence of avian dispersers, the landscape of Guam might change substantially, with clumps, or indeed, rings, of single species and wide-open space in between.
Photo by Isaac Chellman
