After Invasions: Can an ant takeover change the rules?

A rare before-and-after study of the invasion of an exotic species shows the newcomer swiftly disassembling the community, say ant biologists.

Before Argentine ants (Linepithema humile) swept into a nature preserve in northern California, some 20 species of native ants worked the landscape in largely segregated domains, says Nathan Sanders of Humboldt State University in Arcata, Calif. However, the invaders wiped out that pattern, Sanders and his colleagues report in an upcoming Proceedings of the National Academy of Sciences.

"This is the first time anyone has shown how fast an invasion can disassemble a community," says Sanders.

The data in the new paper are "very striking and will cause a lot of ecologists to think," says Thomas E. Miller of Florida State University in Tallahassee.