CULL OF THE WILD

A British ecologist wrestles with the ethical conundrums inherent in controlling invasive animals.

The introduction of invasive species is almost always caused by human actions. For example, the arrival of shipborne rats to a small Australian island led to “the extinction of 5 endemic bird, 13 invertebrate and 2 plant species,” while in the U.S. “already well-fed domestic cats” account for the deaths of 2.3 billion birds annually. Warwick, a champion of hedgehogs in his native England and the author of A Prickly Affair and Linescapes, allows that there are all sorts of philosophical problems with controlling alien predators in ecosystems—even those cute hedgehogs, which feast on juicy skinks on one specimen island in New Zealand. Killing is one option; however, the author asks, “What had the hedgehogs done to deserve that sort of treatment?” The solution has proved somewhat easier on a Scottish island where invasive hedgehogs can be returned to the mainland, where they are part of the ecosystem. It turns out to be more difficult in the enclosed dynamics of island ecologies, where, when one predator has started to cause damage, the tendency has been to introduce another predator to control it—e.g., masked owls on that rat-infested Australian island, which, once the rats were reduced, turned to feeding on native birds and lizards. Warwick’s narrative is sometimes repetitive, but his central point remains: Given that we know that animals are capable of suffering, is it right to take the utilitarian view that the pain of a few is worth the salvation of the many? It’s a problem that we’re likely to confront ever more frequently as climate change forces animal species to relocate to new places—becoming invaders, in other words, and thus both predator and prey.

A thoughtful analysis of how to accommodate animal rights in an era of unprecedented environmental change.