Reliance on unverifiable observations hinders successful conservation of wildlife species

Jun 23, 2008
Sample Set of Evidentiary Standards
A sample set of evidentiary standards based on a gradient of increasing species rarity. The relative reliability of data types is expected to vary among organism groups. Credit: McKelvey et al.

Nearly any evidence of the occurrence of a rare or elusive wildlife species has the tendency to generate a stir. Case in point: in February 2008, remote cameras unexpectedly captured the images of a wolverine in the central Sierra Nevada, an area from which the species was believed to be extinct since 1922. But frustratingly few observations prove to be so conclusive. So what, then, are managers to make of unverifiable observations, especially those that are not diagnostic?

Researchers from the U.S. Forest Service's Pacific Northwest and Rocky Mountain Research Stations examined three cases of biological misunderstandings in which unverifiable, anecdotal observations were accepted as empirical evidence. Ultimately, they found that this acceptance adversely affected conservation goals for the fisher in the Pacific states, the wolverine in California, and the ivory-billed woodpecker in the southeast by vastly overestimating their range and abundance. The researchers' findings appear in the current issue of the journal BioScience.

"These cases revealed that anecdotal data can be important to conservation by supplying preliminary data, such as early warnings of population declines," said Kevin McKelvey, a research ecologist based in Missoula, Mont., and the study's lead investigator, "but conclusions regarding the presence of rare or elusive species must be based on verifiable physical evidence."

In their study, the researchers found that the dependability of species occurrence data depends on both the intrinsic reliability of each record as well as the rarity of the species in question, because the proportion of false positives increases as a species becomes rarer. To help managers determine the suitability of evidence in conservation decisionmaking, the researchers developed a gradient of evidentiary standards for data that increases in rigor along with species' rarity. This "sliding scale" of standards might permit the use of anecdotal data, the least reliable form, in decisionmaking when the species in question is common, for example, but require indisputable physical evidence for a species thought to be extinct. The authors also encourage professional societies to debate evidentiary standards for their organisms of interest and to establish rules for using occurrence data.

"Over the years, many state and federal management agencies have placed a lot of emphasis on compiling sighting reports and other unverifiable wildlife observations" said Keith Aubry, a research wildlife biologist based in Olympia, Wash., and one of the study's co-investigators. "Unfortunately, the uncritical use of such observations has largely impeded conservation goals, not advanced them."


Source: USDA Forest Service, Pacific Northwest Research Station

Explore further: Tracking giant kelp from space

add to favorites email to friend print save as pdf

Related Stories

Scientific Games strikes $3.3B deal to buy Bally

38 minutes ago

Scientific Games plans to pay about $3.3 billion to buy Bally Technologies in a deal that would combine makers of gambling equipment ranging from slot machines to instant-win lottery games.

'Wetting' a battery's appetite for renewable energy storage

40 minutes ago

Sun, wind and other renewable energy sources could make up a larger portion of the electricity America consumes if better batteries could be built to store the intermittent energy for cloudy, windless days. Now a new material ...

Recommended for you

Australia launches 'Green Army' for environment

1 hour ago

Australia on Saturday launched its 'Green Army' which plans to recruit up to 15,000 young people for projects to conserve and rehabilitate the environment—the biggest land care mobilisation in the nation's ...

Tracking giant kelp from space

19 hours ago

Citizen scientists worldwide are invited to take part in marine ecology research, and they won't have to get their feet wet to do it. The Floating Forests project, an initiative spearheaded by scientists ...

Heavy metals and hydroelectricity

21 hours ago

Hydraulic engineering is increasingly relied on for hydroelectricity generation. However, redirecting stream flow can yield unintended consequences. In the August 2014 issue of GSA Today, Donald Rodbell of ...

What's wiping out the Caribbean corals?

22 hours ago

Here's what we know about white-band disease: It has already killed up to 95 percent of the Caribbean's reef-building elkhorn and staghorn corals, and it's caused by an infectious bacteria that seems to be ...

User comments : 0