Invasive species often thrive in new environments in part because they have an unfair advantage, California researchers say.
Researchers at the University of California, Santa Barbara and the federal government€™s Western Ecological Research Center say the foreign species suffer less illness and have about half as many parasites as their native competitors.
Parasites usually serve to cut down on what otherwise might be soaring populations. The researchers say native parasites can also be imported to rein in the healthy invaders. But they warn that brings dangers as well if the parasites learn to feed off native populations.