It has long been known that migratory birds can make use of the earth’s magnetic fields to navigate. Birds read the angle that magnetic fields create on the ground and thereby determine how far north or south they are of the magnetic equator and the magnetic pole. But how do they do this? Is there some unknown “magnetic sense”? It seems that birds can actually see magnetic fields-providing the lighting conditions are right. Experiments on redbreasts carried out by a zoo-ecologist at Lund University in Sweden have shown at what light frequencies magnetic force lines appear.
In the early 1990s German scientists demonstrated that in green light birds could find their expected migratory route in relation to the magnetic field. But if the light was yellow or red instead, the birds went astray, taking off in random directions. These German researchers used light-emitting diodes. Rachel Muheim, at the Department of Ecology at Lund, has performed similar experiments but using fiber optics and filters, which yields a narrower and more controlled spectrum.
The classic experimental set-up for such experiments is a funnel-shaped cage where the birds cannot see the sky-birds also use the sun and stars for navigation purposes. Electronic sensors or colors on the walls reveal what route they would like to follow to get out of the cage. Rachel Muheim studied how redbreasts behaved in this situation when they were exposed to green, yellow-green, and red light.
“The birds could navigate in the right direction in low-intensity green light but not in yellow-green light. The frequency difference between green and yellow-green light is very small, which shows how sensitive these perceptions are,” says Rachel Muheim, and continues:
Göran Frankel | alfa
First line of defence against influenza further decoded
21.02.2018 | Helmholtz-Zentrum für Infektionsforschung
Helping in spite of risk: Ants perform risk-averse sanitary care of infectious nest mates
21.02.2018 | Institute of Science and Technology Austria
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
21.02.2018 | Earth Sciences
21.02.2018 | Health and Medicine
21.02.2018 | Life Sciences