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."
Yasmeen Sands | EurekAlert!
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A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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