Where Conservation Biology and Conservation Ballistics Meet


Turning the Tide: the Eradication of Invasive Species. Proceedings of the International Conference on Eradication of Island Invasives. Veitch, C. R., and M. N. Clout, editors. 2002. Occasional paper no. 27. Species Survival Commission, World Conservation Union, Gland, Switzerland, and Cambridge, United Kingdom. 422 pp. $36.75 (paperback). ISBN 2–8317–0682–3.

With the exception of the last few decades, the modern extinction event has been largely an insular phenomenon, mostly due to the devastating effects of invasive introduced species. Ironically, many of these extinctions of island species would have been the easiest to avert if only concerted action had been taken to eradicate the offending organisms. With the exception of most Australian and New Zealand ecologists, the problems associated with introduced species have not been paramount in most ecologists' or resource managers' minds, and relatively few eradication programs had been attempted in the Northern Hemisphere until relatively recently. All this is beginning to change, and this volume testifies to that change.

There are invasive species that represent nearly every imaginable taxon, but any list of organisms perceived to be seriously damaging invasive species on islands is likely to be dominated by plants and mammals. This is not to say that such a list would necessarily be accurate, but this is the perception. Interestingly, the papers presented at this conference reflect that perception.

The International Conference on Eradication of Island Invasives represents an important milestone in the newly emerging sciences of eradication biology and restoration ecology. But I should point out that the majority of papers in this volume are reports of eradication programs for mammals, with a significant minority of papers on plants. The volume consists of 51 papers (not counting the preface and keynote address) and 21 abstracts. Thirty-three of the papers and 13 of the abstracts concern vertebrates. The focus on mammal eradication should not come as a surprise for several reasons: mammals are often ecologically dominant and cause severe changes in endemic biota including extinctions, mammal eradications probably have a higher likelihood of being successful and thus have been attempted more often, and the conference attendees and contributors naturally had a bias toward the southern hemisphere because of the conference's location. More mammal-eradication programs have probably been undertaken in Australia and New Zealand than in the rest of the world together.

In general, the papers in this volume present a nuts-and-bolts approach to eradication—an appropriate approach considering that the conference was a first attempt to gather the world's experts on eradicating invasive species from islands. For ecologists and managers planning or even contemplating an eradication program for invasive mammals or plants on islands, the volume is a veritable how-to guide.

Beyond the actual eradications reported, a number of papers take the reader beyond the eradication program itself. For example, Kessler et al. and Bullock et al. focus on responses of various biota to eradication programs. Zavaleta's paper on other outcomes of eradication programs is one all managers conducting an eradication program should read. Zavaleta correctly points out that an eradication is simply an unreplicated experiment (albeit a necessary one) that is focused on changing the numbers of a single species and that is likely to have uncertain results. Zavaleta provides a prototype decision tree for managers to consult before considering an eradication program and provides an ideal compliment to the more nuts-and-bolts approach to planning an eradication program presented, for example, by Cromarty et al., who only address the actual eradication and not potential consequences.

The human dimension, primarily represented by animal-rights advocates, is discussed briefly by Parkes et al. and Schuyler et al. and is alluded to in both Clout and Veitch's preface to the conference and Simberloff's keynote address. Granted, this conference was attended primarily by those in the forefront of eradication biology, but the organizers would have done even better if they had been able to ensure that individuals representing animal rights groups were presenting, if for no other reason than to document their inclusion.

As with any conference, not all the papers are of uniform quality. The editors have done an excellent job of bringing them to a fairly consistent writing quality. The reviewers seem to have mostly done a thorough job as well, although in one paper a mongoose eradication is described as being conducted because of the damage the animals were inflicting on taro, sweet potato, and watermelon crops. Mongooses don't eat these things, and the author furthermore presented information about the diet of the mongoose that demonstrated they ate only animal matter. This conflicting information made little sense to me and should have been caught earlier.

Glitches aside, this proceedings is an outstanding collection of papers that all island ecologists and managers should use as a valuable reference. It is a handy reference to the techniques and targets of eradicating invasive species on islands and also for who is doing it. It provides a wealth of valuable information and a source book for whom to contact for additional information. Is it a “conference spanning the entire field of eradication” (Simberloff, keynote address)? Probably not even close, but that shouldn't be a criterion by which to judge it or in any way be considered a negative judgment.

In the simplest of terms, restoration of insular biological communities or even preservation of sensitive insular species may be quite impossible without eradication of some invasive species, and this volume provides a wealth of information to be applied to such restoration.