The aliens have landed and they’re killing the
natives. It may sound like the plot of a bad movie, but it’s real
life: Alien species threaten the survival of native plants and
animals across the country. In the report, America’s Least Wanted,
The Nature Conservancy has named the 12 most threatening invaders
of our nation’s ecosystems, and five of this “dirty dozen” are on
the loose in the West. The five – tamarisk, purple loosestrife,
leafy spurge, the marine plant hydrilla, and flathead catfish –
choke out local species or prey on them. Exotic species nationwide
contribute to the decline of 42 percent of all federally listed
threatened or endangered species, and 79 alien species have already
cost the country some $97 billion, says the conservancy. The free
30-page report, edited by Bruce A. Stein and Stephanie R. Flack,
can be ordered from Laurie Bullard at The Nature Conservancy at
703/841-4828, or seen on the web at
http://www.tnc.org/science/library.
This article appeared in the print edition of the magazine with the headline Alien invasions.
Republish our articles for free, online or in print, under a Creative Commons license.
