When Should Scientists Kill?

Lost but now is found: A Holdridge’s toad. (Photo: Juan G. Abarca Alvarado)

In May 2006, in the Himalayan foothills of northern India, an astronomer and ecologist named Ramana Athreya caught two of an elusive bird species in a mist net. He‘d first spotted these birds and recognized them as something unfamiliar in 1995. Now, after more than 10 years, he held the prize in his hand. It was unmistakably a new species, the sort of thing most ornithologists can only dream of discovering.

The usual procedure would have been to kill those specimens as mercifully as possible and carefully preserve them for science. That’s been the usual procedure for the past 250 years of species discovery and identification. Having the bird literally in hand has been the essential means of defining a species, both for the original scientific description and as source material for later researchers.

Instead, to the chagrin of many scientists, Athreya set the birds free. “We thought the bird was just too rare for one to be killed,” he said at the time. “With today’s modern technology, we could gather all the information we needed to confirm it as a new species. We took feathers and photographs, and recorded the bird’s song.” Even without a complete bird, that was enough to publish a scientific description of the species, now known as Bugun liochichla.

An article out today in the journal Science argues, in essence, that more scientists should follow Athreya’s example. That is, they should think twice before taking specimens, particularly when rediscovering species that had been presumed extinct. Those kinds of rediscoveries have happened more than 350 times over the past century or so, and for an excited naturalist, the instinct is to bring home proof in the form of a specimen.  But such collecting risks consigning the species to “re-extinction,” as the headline of the new article puts it.

“This is the only article I have ever written out of rage,” coauthor and herpetologist Robert Puschendorf said, in an interview. A few years ago, in Costa Rica’s Monteverde Cloud Forest Reserve, he was present when two colleagues spotted a stream-dwelling frog species that had until then been considered extinct–and collected it for one of their museums. He acknowledged that he had once done the same thing, adding, “In my defense, I’ll say that there were tons of them, the night we rediscovered the species. I’m not proud of what I did, but at least I did not collect the only individual of a species.”

The new article describes one species, the great auk on Eldey Island in Iceland, where “centuries of exploitation for food and feathers” severely reduced populations, “but overzealous museum collectors also played a role in its extinction.” The last breeding pair were collected in the 1850s by a fisherman, to be preserved for science, their internal organs ultimately deposited at the Zoological Museum in Copenhagen. The article also links professional and amateur collecting to the decline of Mexico’s elf owl.

Puschendorf acknowledged that collecting specimens and preserving them in a museum can provide essential information for scientists. He began his own career examining museum specimens of frogs to see when and where the deadly chytrid fungus first appeared. That kind of information can help to save species from extinction. “I’m definitely not saying, ‘Do not collect,’ ” said Puschendorf. “What I’m saying is ‘Think about when you’re to going to collect.’ ”

As an alternative to collecting, the article notes that “most smartphones have a camera and a voice recorder sufficient to gather high resolution images as well as an organism’s call” and that combining this data with genetic information from skin swabs or other sources “can be just as accurate as the collection of a voucher specimen.” It suggests that this information should be stored in digital repositories for access by other scientists.

If Puschendorf’s article was written out of rage, it is likely to elicit rage from other scientists. “This guilt-driven paper is as bad as I was afraid it would be,” said Piotr Naskrecki, associate director of the E.O. Wilson Biodiversity Laboratory at Harvard, in an email. The examples it cites of negative impacts from collecting “are rare exceptions” rather than the rule, and the article “offers naive, mostly impractical recommendations that apply to a tiny handful of potential cases. Try to document a new ant species using your phone and a recorder, or a new fungus using molecular markers in a group where no species has ever been sequenced.” Naskrecki worried that publication in a high-profile journal such as Science “will reinforce many readers’ belief that collecting and natural history collections are outdated relicts of Victorian science that can and should be phased out. Very disappointing.”

To put the putative threat from collecting in perspective, mammalogist Kristofer Helgen noted, also by email, that the mammal collection at the Smithsonian Institution, where he works, “reflects almost 200 years of targeted collecting, representing many hundreds, if not thousands, of expeditions. It is the single most important resource globally for understanding the biology of mammals. However, this collection amounts, in total number of specimens, to only about one-half of the total number of animals estimated to be road-killed in the U.S. per day.”

Helgen added, “I do agree that lethal collecting of truly endangered taxa is a very important ethical issue and for mammals where it might threaten survival of populations, is certainly to be avoided, and this is already reflected in the permissions required and normal ethical standards currently in operation in professional field biology and collections-based science.” But within those community standards, collecting “provides arguably the most rigorous source of data not just for definitive identifications but also for understanding variation in nature, geographic distributions, conservation prioritization, ecology of health and disease, environmental change through time, and many other very important and practical aspects of our world.”

Debate along these lines is likely to be loud and passionate, and that’s a good thing, says Ben Minteer, a coauthor of the new article. He also points out that it is an old story. The debate about using lethal methods dates back at least a century, to another article published in Science, by the pioneering vertebrate biologist Joseph Grinnell.

“The type of field observer who depends solely on long-range identification is becoming more and more prevalent,” Grinnell wrote. “But the opera-glass student, even if experienced, can not be depended upon to take the place of the collector. Accuracy in identification of species and especially subspecies rests for final appeal upon the actual capture and comparison of specimens.” Grinnell thought that the prejudice against collectors was the work of “extreme sentimentalists.” Minteer and Puschendorf noted that precedent in their original draft for the new Science article and also quibbled that Grinnell didn’t know about genetics or the perils of species rediscovery.

Perhaps in the interest of stirring up the debate, and simplifying the story, the editors of modern-day Science cut out that reference.