Do biologists really need dead animals? Article inflames debate.

Upon discovering a new species, it is customary for field biologists to collect – and kill – 'voucher specimens.' But is that really necessary?

Two camps of scientists are vigorously debating the value of killing animals as "voucher specimens" of new or threatened species. The exchange unfolded in the current issue of Science, a month after four scientists had published a general exhortation to explore nonlethal ways of identifying newly discovered animals.

"Cases such as the extinction of the great auk remind us what is at stake in taking animals from small and declining populations," wrote Arizona State University environmental ethicist Ben Minteer, with three co-authors, in the original paper, titled 'Avoiding (Re)extinction.'

The great auk was a flightless, penguinlike bird that dwelled in the North Atlantic until human activities, including collection for museums and universities, drove it to extinction in the 19th century. That all happened before global biodiversity loss became a serious concern for scientists, "yet, there is still a strong and widespread impulse to procure specimens of rare of rediscovered species for scientific purposes," wrote the scientists in the April 18 issue of Science.

"Cultural traditions within a research community can reinforce the collection of voucher specimens even where it is not necessary," they added.

A group of 123 such tradition bearers – scientists and museum professionals from 26 countries – took umbrage at this suggestion, and signed a stern letter of response aimed at discrediting Dr. Minteer's examples and defending the importance of removing entire animals from their habitat. 

"Studies of morphological diversity and its evolution are impossible without whole specimens," states the letter penned by Luiz Rocha, Assistant Curator at the California Academy of Sciences (CAS).

What's more, he adds, the 102 great auks immortalized in collections were a mere drop in the birds' tipping bucket, compared to the millions killed for food, oil, and feathers during their tenure on Earth.

"The arguments of Minteer et al. erroneously portray the critical importance of scientific collecting in a negative light and distract from the primary causes of modern extinction: habitat degradation and loss, unsustainable harvesting, and invasive species," he writes.

The response is accompanied by a photo of nine exquisitely colorful specimens of different reef-dwelling shrimp, which the authors claim cannot be collected nonlethally. "The process of bringing them from those depths, and essentially opening up that rock or coral structure to get them out or even see what's in there, does cause harm," says CAS spokesman Stephen Bedard.

But Minteer says the response misrepresents his paper as an attack on voucher specimen collection, when it was simply a call to seriously consider how the practice impacts vulnerable species. "We're saying that in some cases collection can pose an increased risk among small populations."

The impetus behind the paper, says Minteer, was the recent experience of his co-author, Robert Puschendorf, a researcher at Plymouth University in the UK who studies declining amphibian populations. After repeatedly watching colleagues kill individual members of small, endangered, or yet-unknown populations, Dr. Puschendorf wrote to the colleagues who would become the paper's co-authors.

"His concern was that this had become so automatic in field biology, that it was being done even in cases where a specimen wasn't needed," recalls Minteer.

In the column that resulted from those conversations, the four authors underlined the value of photographs, molecular data, and voice recorders, as less destructive and sometimes equally useful alternatives to pins, nets, and formaldehyde. "Such nonlethal techniques were used successfully for the identification of the bird Bugun liocichla, a species that was newly discovered in India in 2006," wrote Minteer and his colleagues. "The bird's discoverer deliberately chose not to collect a voucher specimen for fear of imperiling the population; instead, a combination of photos, audio recordings, and feathers were used to distinguish the species."

Minteer, who was surprised by what a sharp nerve their column struck, sees both scientific and ethical dimensions to the conflict. "I think there is an empirical disagreement about whether or not you can actually learn more from a dead organism, than other forms of documentation." But, he adds, "It's partly maybe a different set of impulses about how we would value conservation alongside the acquisition of scientific knowledge."

Indeed, Rocha's response clearly emphasizes knowledge acquisition. "Because an estimated 86% of species on the planet remain unknown, our goal should be to document biodiversity as rigorously as possibly through carefully planned collections so that it can be effectively preserved and understood."

Whereas Minteer believes that scientists' duty to conserve the species should trump their impulses to complete their collections, if the two conflict. There are serious trade-offs to consider, he says, when "knowing everything there is to know about the world, could also extinguish the source of that knowledge."