Tipping the scales towards native species

by Aaron Gilbreath

When biologist Phil Pister used buckets to rescue the last Owens pupfish from an evaporating pool, he knew that if he “tripped over a piece of barbed wire,” the species was history. Thirty-eight years later, the pupfish survives only because scientists move the fish pool-to-pool and constantly trap predators. In Unnatural Landscapes, Ceiridwen Terrill, a professor at Concordia University in Portland, travels to four arid sites to show how scientists fight to protect indigenous organisms from invasives like Russian thistle, iceplant and Louisiana crawfish.

Unnatural Landscapes provides a tactile, enlightening introduction to the typically academic subject of invasive ecology. Terrill puts prickly cheatgrass in your sock, lets a crawfish clamp your finger. Complicated concepts come to life as she explores Pyramid Lake’s pelican preserve in Nevada, the Mojave’s thermal pools, Baja’s Midriff Islands and California’s fragile Santa Cruz Island. She finds that tipping the odds in favor of the natives often requires eradicating the nonnatives. Frequently, that means spilling blood — and provoking controversy.

Protest ensued when the National Park Service approved a 2005 feral pig hunt on Santa Cruz Island. “Save the Pigs!” proclaimed one aerial banner at a rally. Like “four-legged rototillers,” the pigs uprooted native plants such as island barberry, spread nonnative fennel and helped whittle the endangered island fox population from 1,300 down to 100 in a decade. But our cheers for the fox’s anticipated rebound may be tempered by a former park superintendent’s description of the hunt: “When sows were shot, their piglets were caught by dogs (that) … would tear into and mangle smaller pigs. Large pigs would fight the dogs, occasionally injuring or killing one.”

Like it or not, Terrill says, humans are now in the ecological management business. Public education — removing invasive ecology from the realm of “a few specialists” and government agencies — can awaken people to the scope of the problem, and perhaps make eradication’s uglier side more acceptable. “(Once) people understand the significant threats invasive species pose,” writes Terrill, “they will be eager to be part of the solution.” This book is a great step toward that goal.

Unnatural Landscapes: Tracking Invasive Species
Ceiridwen Terrill
240 pages, softcover: $17.95.
University of Arizona Press, 2007.


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