Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemical reaction in birds provides sense of direction during migratory flights

13.05.2004


Study could help identify mechanism of magnetoreception in animals and humans



Migrating birds stay on track because of chemical reactions in their bodies that are influenced by the Earth’s magnetic field, a UC Irvine-led team of researchers has found.

The birds are sensitive even to rapidly fluctuating artificial magnetic fields. These fields had no effect on magnetic materials such as magnetite, indicating that the birds do not rely on simple chunks of magnetic material in their beaks or brains to determine direction, as experts had previously suggested.


The results are reported in the May 13 issue of Nature. The study is the first to reveal the mechanism underlying magnetoreception – the ability to detect fluctuations in magnetic fields – in migratory birds.

In the study, Thorsten Ritz, assistant professor of physics and astronomy, and colleagues exposed 12 European robins to artificial, oscillating magnetic fields and monitored the orientation chosen by these birds. The stimuli were specially designed to allow for responses that could differ depending on whether birds used small magnetic particles on their bodies or a magnetically sensitive photochemical reaction to detect the magnetic field.

“We found that the birds faced in the usual direction for their migration when the artificial field was parallel to the Earth’s natural magnetic field, but were confused when the artificial field was applied in a different direction,” said Ritz, the lead author of the paper. “Since the artificial field’s oscillations were too rapid to influence magnetic materials like magnetite, it suggests that the most likely mechanism for magnetic orientation in these birds involves tiny changes to magnetically sensitive chemical reactions, possibly occurring in the eyes of the birds – we are not sure.”

In the experiments, the robins could walk and flutter in their cages but could not fly. The birds oriented well in the Earth’s magnetic field alone, but were disoriented in the presence of a broad-band (0.1-10 megahertz) and 7 megahertz oscillating field, aligned at a 24 or 48 degree angle to the Earth’s magnetic field. When the same 7 megahertz oscillating field was aligned parallel to the Earth’s magnetic field, the robins showed normal migratory orientation again.

“Unlike our senses involving vision, hearing, smell and touch, we do not know what receptors underlie magnetoreception,” Ritz said. “Migratory birds have long been known to possess a magnetic compass that helps them find the correct direction during their migratory flights. It has remained unknown, however, how birds can detect the direction of the Earth’s magnetic field.

“Now, our study points to what we need to look fora molecular substrate for certain chemical reactions. That is, we can rule out magnetic materials in birds’ beaks and elsewhere as being possible candidates. Magnetite in the beaks, however, may play a role in detecting the strength but not the direction of the Earth’s magnetic field.”

The experiments on the birds were conducted in a six-week period in 2003 in Frankfurt, Germany, in the laboratory of Wolfgang and Roswitha Wiltschko, co-authors of the paper, who developed the behavioral experimental setup used in the study for testing magnetic orientation in birds. During migratory unrest, the birds could move in their cages. Each cage was funnel-shaped, lined with coated paper and measured approximately 1.5 feet in diameter. When the birds moved in the cages, they left scratch marks that were counted subsequently by the researchers and analyzed.

To produce artificial oscillating fields, the researchers fed high-frequency currents from a signal generator into a coil that surrounded four test cages. The coil, with a diameter of approximately two meters, could be moved to change the alignment of the oscillating field. Each bird was tested once a day during dusk for a period of approximately 75 minutes.

Besides the Wiltschkos of J. W. Goethe-Universität, Germany, Ritz was joined in the study by John B. Phillips of Virginia Tech and Peter Thalau of J. W. Goethe-Universität.

The research was funded by the Deutsche Forschungsgemeinschaft and the Fetzer Institute.

About the University of California, Irvine: The University of California, Irvine is a top-ranked public university dedicated to research, scholarship and community. Founded in 1965, UCI is among the fastest-growing University of California campuses, with approximately 24,000 undergraduate and graduate students and about 1,300 faculty members. The third-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3 billion.

Iqbal Pittalwala | UC Irvine
Further information:
http://today.uci.edu/news/release_detail.asp?key=1151

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>