In a time of global climate change and rapidly disappearing habitat critical to the survival of countless endangered species, there is a heightened sense of urgency to confirm the return of animals thought to be extinct, or to confirm the presence of newly discovered species. Field biologists traditionally collect specimens to distinguish the animals -- or to confirm that they do indeed exist in the wild. Researchers at Arizona State University and Plymouth University in the United Kingdom want to change the way biologists think about the "gold standard" of collecting a "voucher（收据，证人）" specimen for species identification. They suggest that current specimen collection practices may actually pose a risk to vulnerable animal populations already on the brink of extinction.

"We are drawing attention to this issue as an important question bearing on the ethical responsibilities of field biologists. It concerns not only an increased extinction threat to re-discovered species, but also the collection of specimens from small populations more generally," said Ben Minteer, an environmental ethicist and conservation scholar in ASU's School of Life Sciences.

"Because these populations are very small and often isolated, they are incredibly sensitive to over-collecting," added Minteer, also the Arizona Zoological Society Chair at ASU. "Combine the understandable impulse to confirm something really important -- such as that a species is not, in fact extinct -- with the sensitivity of a population to collection and you've got a potentially significant conservation issue."

The researchers raise the issue in the April 18 issue of the journal Science. In the article, Minteer and his colleagues cite examples of the decline or loss of a range of animal species due to the impact of field collections by both professional scientists and amateur（业余的） naturalists. There are cases of now-extinct birds, as well as the loss and rediscovery of amphibians in Costa Rica.