Navigation Links
Overbearing colored light may reveal a second mechanism by which birds interpret magnetic signals

Magnetic orientation is critical to the migratory success of many bird species. By studying the influence of light on the ability of migratory birds to orient to magnetic signals, researchers have found clues to suggest that birds' orientation abilities may be more complex than previously thought and that birds may be able to interpret magnetic signals by more than one mechanism. The work is reported in Current Biology by a team including Thorsten Ritz, of the University of California, Irvine, and Wolfgang and Roswitha Wiltschko, of the University of Frankfurt, Germany.

It has been known for many years that birds possess a magnetic "inclination compass," which essentially allows birds to obtain directional information from the magnetic field by interpreting the angle of magnetic-field lines with regard to the horizon rather than by interpreting the magnetic field's polarity. Previous work by Dr. Ritz had suggested that in interpreting magnetic signals, birds employed a so-called chemical compass that worked by way of chemical reactions in specialized photopigments in their eyes. The chemical-compass idea implied that magnetoreception was light dependent, and this possibility was subsequently given support by work from the Wiltschko team showing that the orientation of European robins, a night-migrating species, was influenced by the intensity of light in the blue-green spectrum.

In the present study, the Ritz and Wiltschko groups teamed up to analyze the orientation behavior under turquoise light in detail and revealed an unexpected phenomenon: Increasing the intensity of turquoise light changes the birds' orientation significantly, in comparison to dimmer light levels. The researchers found that in dim turquoise light, similar to that found about 33 minutes after sunset, the birds show normal migratory orientation, with the seasonal shift between southerly directions in autumn and northerly directions in spring. Tests under specific magnetic conditi ons clearly showed that this orientation involved the inclination compass and suggested that it is based on the type of "chemical compass" processes predicted by the Ritz model.

However, the researchers also found that under brighter turquoise light, corresponding to light levels found 20 min after sunset, the birds still orient by the magnetic field, but they no longer show the seasonal change between spring and autumn and instead head north in both seasons. This behavior did not appear to involve the normal inclination-compass and chemical-compass mechanisms.

The new findings show that bright-colored light interferes with magnetoreception such that migratory birds can no longer obtain the information required to head into their migratory direction. The findings point to the existence of two distinct mechanisms of magnetoreceptors in the birds--an inclination compass and a polarity-driven compass. It is especially intriguing that under some conditions, birds appear to switch to the polarity-type magnetic response, which is based on a mechanism of a very different nature than that thought to contribute to the inclination mechanism.


'"/>

Source:Cell Press


Related biology news :

1. Researchers discover way to make cells in the eye sensitive to light
2. Recent breakthroughs in common adult leukemia highlighted in New England Journal of Medicine
3. Bacteria collection sheds light on urinary tract infections
4. Sea skate experiment sheds light on human cell transport
5. X-Ray Beams And Fruit Fly Flight Simulator Aid Scientists View Of Muscle Power
6. McGill researchers shed light on formation of carcinogen in food
7. Scientists discover how plants disarm the toxic effects of excessive sunlight
8. Medical molecules designed to respond to visible light that can penetrate tissue
9. Genetic defects give the immune system the green light to attack the pancreas
10. Researchers find gene that may be at root of potato blight
11. Remote control flies? Fly behavior controlled by laser light
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/31/2016)... , March 31, 2016 ... ) ("LegacyXChange" or the "Company") LegacyXChange is ... users of its soon to be launched online site ... https://www.youtube.com/channel/UCyTLBzmZogV1y2D6bDkBX5g ) will also provide potential shareholders ... of DNA technology to an industry that is notorious ...
(Date:3/22/2016)... PUNE, India , March 22, 2016 ... new market research report "Electronic Sensors Market for ... Fingerprint, Proximity, & Others), Application (Communication & ... and Geography - Global Forecast to 2022", ... consumer industry is expected to reach USD ...
(Date:3/17/2016)... 17, 2016 ABI Research, the leader ... global biometrics market will reach more than $30 ... from 2015. Consumer electronics, particularly smartphones, continue to ... anticipated to reach two billion shipments by 2021 ... Pavlakis , Research Analyst at ABI Research. "Surveillance ...
Breaking Biology News(10 mins):
(Date:5/31/2016)... IN (PRWEB) , ... May 31, 2016 , ... The ... Model Aviation Museum that will be on display Memorial Day through Labor Day 2016. ... Henry Chaffee, and Clark Chaffee. , Bill Chaffee won first place for Senior ...
(Date:5/27/2016)... Jersey and READING, ... -- Indegene ( http://www.indegene.com ), ... marketingorientierten Lösungen für die Life-Science-Branche, Pharmaunternehmen und ... bekannter weltweiter Anbieter von innovativen wissenschaftlichen Support-Services ... des Starts von IntraScience heute den Ausbau ...
(Date:5/26/2016)... , May 26, 2016 Despite ... see value in this space. Today,s pre-market research on ActiveWallSt.com ... Radius Health Inc. (NASDAQ: RDUS ), Cerus Corp. ... ARWR ), and Five Prime Therapeutics Inc. (NASDAQ: ... technical briefings at: http://www.activewallst.com/ ...
(Date:5/25/2016)... ... May 25, 2016 , ... Thailand’s Board of ... 2016 in San Francisco. Located at booth number 7301, representatives from the Thai ... and discuss the Thai biotechnology and life sciences sector. , Deputy Secretary ...
Breaking Biology Technology: