Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Habitat loss, not poison, better explains grassland bird decline

24.06.2014

Contrary to recent well-publicized research, habitat loss, not insecticide use, continues to be the best explanation for the declines in grassland bird populations in the U.S. since the 1980s, according to a new study by ecologists.

Last year, a pair of researchers linked the drop in the populations of grassland bird species, such as the upland sandpiper and the Henslow's sparrow, to insecticide use, rather than to a rapid decline of grasslands, a more commonly accepted theory. However, after re-examining the data, Penn State and U.S. Department of Agriculture researchers now believe that the loss of habitat continues to be the best explanation, said Jason M. Hill, a postdoctoral research associate in ecosystem science and management, Penn State.

"Many people think of grassland loss as something that happened long ago in North America, but the amount of grassland lost since the 1980s is absolutely staggering, whereas the insecticide use greatly declined prior to the 1990s," said Hill.

The researchers cited earlier studies that documented a loss of approximately 97,000 square kilometers -- an area larger than the stats of Indiana -- of grasslands in the U.S. between 1982 and 1997 primarily due to the expansion and intensification of agricultural practices.

The researchers were surprised that the other researchers excluded lands from the Conservation Reserve Program lands in their analysis. The CRP pays farmers to remove environmentally sensitive lands, especially grasslands, from agricultural production. Because grassland bird species tend to do better in states with larger areas set aside in the conservation land program, excluding the conservation land program data may have skewed their results, said Hill.

"We reanalyzed their data in a more statistically-appropriate way, including CRP acreage, and found 1.3 to 21 times more support that habitat loss was more strongly connected to grassland bird declines than insecticide use," said Hill. "Grassland bird trends were positively associated with the acreages of CRP lands and some types of pastures."

Erroneously emphasizing insecticides as the principle cause of grassland bird declines may inadvertently divert attention and funding away from land conservation programs such as CRP, according to the researchers.

"Conservation Reserve Program contracts are not being renewed," said J. Franklin Egan, research ecologist, USDA-Agricultural Research Service, who worked with Hill. "My biggest concern is that we get distracted and lose focus on preserving the remaining grasslands."

Grasslands, especially in agricultural landscapes, also provide tremendous benefits to humans through erosion reduction and water filtration as well as offering habitat to numerous grassland-obligate species from black-footed ferrets to Dakota skippers.

The loss of grasslands is a global problem, according to the researchers, who report their findings in the journal PLOS One.

"Grasslands and grassland-obligate species are declining not just across North America, but across the globe," said Hill.

Grassland bird species use the living and dead vegetation in grasslands to build nests and for use as cover.

"Grasslands are easily converted to farmland for row crops, such as corn and soybeans," said Egan, "Grassland species, with few exceptions, cannot survive on these intensive agricultural lands."

The researchers examined population data of grassland species in the 48 contiguous United States from the U.S. Geological Survey North American Breeding Bird Survey. In addition to information provided by the researchers on the study of insecticides and grassland birds, they also used data from the U.S. Department of Agriculture and the National Resources Conservation Services. Hill and Egan also worked with Glenn E. Stauffer, a post-doctoral scholar in forest resources, and Duane R. Diefenbach, adjunct professor of wildlife ecology, both of Penn State.

Matt Swayne | Eurek Alert!
Further information:
http://www.psu.edu

Further reports about: CRP Conservation explains grassland habitat humans insecticide insecticides poison species

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF

nachricht Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Research finds new molecular structures in boron-based nanoclusters

13.07.2018 | Materials Sciences

Algae Have Land Genes

13.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>