Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electrosmog Disrupts Orientation in Migratory Birds - An international study published in "Nature

08.05.2014

Below a certain threshold value, electrosmog has no impact on biological processes or even human health – that was the state of scientific knowledge up to now. But for the first time, a research team led by Prof. Dr. Henrik Mouritsen, a biologist and Lichtenberg Professor at the University of Oldenburg, has been able to prove that the magnetic compass of robins fails entirely when the birds are exposed to AM radio waveband electromagnetic interference – even if the signals are just a thousandth of the limit value defined by the World Health Organization (WHO) as harmless.

The findings based on seven years of research by nine Oldenburg scientists, in cooperation with Prof. Dr. Peter J. Hore of Oxford University, are now available in a paper entitled "Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird", published in the latest issue of the renowned scientific journal Nature. Nature underlines the importance of this study by making it the cover story of its May 15th issue.


European robin

University of Oldenburg

"In our experiments we were able to document a clear and reproducible effect of human-made electromagnetic fields on a vertebrate. This interference does not stem from power lines or mobile phone networks", Mouritsen stresses, explaining that electromagnetic interference within the two kilohertz to five megahertz frequency range is mainly generated by electronic devices. "The effects of these weak electromagnetic fields are remarkable: they disrupt the functioning of an entire sensory system in a healthy higher vertebrate."

It all started with a stroke of luck. For around 50 years it has been known that migratory birds use the Earth's magnetic field to determine their migratory direction. Biologists have proven this in numerous experiments in which they tested the birds' navigation abilities in so-called orientation cages. "So we were surprised when robins kept in wooden huts on the Oldenburg University campus were unable to use their magnetic compass", Mouritsen recounts.

Dr. Nils-Lasse Schneider, an electrophysiologist and researcher in Mouritsen's work group, then came up with the idea that set things in motion: he proposed covering the wooden huts, along with the orientation cages they contained, with sheets of aluminium. This did not affect the Earth's magnetic field, which is vital for the birds to navigate, but it strongly attenuated the time-dependent electromagnetic interference – the electrosmog – inside the huts.

The effect was astounding: suddenly the birds' orientation problems disappeared. "Our measurements of the interferences indicated that we had accidentally discovered a biological system that is sensitive to anthropogenic electromagnetic noise generated by humans in the frequency range up to five megahertz", Mouritsen says. The surprising thing here, the biologist adds, was that the intensity of the interference was far below the limits defined by the International Commission on Non-Ionizing Radiation Protection and the WHO.

Considering the potential importance of the finding, Mouritsen and his team performed a large number of experiments to provide evidence of the effect they observed: “Over the course of seven years we carried out numerous experiments and collected reliable evidence, in order to be absolutely certain that the effect actually exists.” Under the leadership of Svenja Engels, Mourtisen's doctorate students conducted numerous so-called double-blind studies. Several generations of students repeated the experiments independently of one another on the Oldenburg campus. What they found was that as soon the grounding of the screens was disconnected or electromagnetic broadband interference was deliberately created inside the aluminium-clad and earthed wooden huts, the birds' magnetic orientation ability was immediately lost again.

Furthermore, the scientists were able to show that the disruptive effects were generated by electromagnetic fields that cover a much broader frequency range at a much lower intensity than previous studies had suggested. This electromagnetic broadband interference is omnipresent in urban environments. It is created wherever people use electronic devices. As expected, it is significantly weaker in rural areas. And indeed, unlike on the University campus, the magnetic compass of the robin did function in orientation cages placed one to two kilometres outside city limits, even without any screening. “Thus, the effect of anthropogenic electromagnetic noise on bird migration is localised. However these findings should make us think – both about the survival of migratory birds as well as about the potential effects for human beings, which have yet to be investigated”, Mouritsen concludes.

Profile
Prof. Dr. Henrik Mouritsen has been teaching and conducting research at the University of Oldenburg since 2002, and obtained his habilitation there in 2005. The Danish biologist has held a Lichtenberg Professorship from the VolkswagenStiftung since 2007. Through its “Lichtenberg Professorships” initiative the foundation funds outstanding scientists in innovative fields of teaching and research. Mouritsen researches the behavioural, molecular, physiological and cognitive mechanisms underlying long-distance navigational abilities in migratory birds. As head of the international research group “Neurosensorik/Animal Navigation” he has contributed substantially to the current state of the art suggesting that the birds use the Earth's magnetic field for orientation in two different ways. Light-sensitive molecules in their eyes enable them to visually detect the compass direction of the magnetic field. Furthermore, the birds seem to have magnetic sensors associated with the ophthalmic branch of the trigeminal nerve, which are connected via neural pathways to the brainstem. Mouritsen's group identified for the first time the areas in the birds' brains involved in both these orientation systems.

“Anthropogenic electromagnetic noise disrupts magnetic compass orientation in a migratory bird” by Svenja Engels, Nils-Lasse Schneider, Nele Lefeldt, Christine Maira Hein, Manuela Zapka, Andreas Michalik, Dana Elbers, Achim Kittel, P.J. Hore, Henrik Mouritsen, Nature.

Weitere Informationen:

http://www.uni-oldenburg.de/ibu/neurosensorik

Dr. Corinna Dahm-Brey | idw - Informationsdienst Wissenschaft

Further reports about: Anthropogenic Birds Migratory Nature biologist experiments importance orientation

More articles from Studies and Analyses:

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union

All articles from Studies and Analyses >>>

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

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication

16.07.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>