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:2/14/2017)... N.C. , Feb. 14, 2017  Wake Forest ... M.D., as its new chief executive officer (CEO). Freischlag ... CEO John D. McConnell , M.D., who last ... position at the Medical Center, after leading it since ... the full scope of Wake Forest Baptist,s academic health ...
(Date:2/10/2017)... Feb 10, 2017 Research and ... "Personalized Medicine - Scientific and Commercial Aspects" to ... ... Diagnosis is integrated with therapy for selection of treatment as ... detection and prevention of disease in modern medicine. Biochip/microarray technologies ...
(Date:2/8/2017)... 2017  Aware, Inc. (NASDAQ: AWRE ), a ... results for its quarter and year ended December 31, 2016. ... was $3.9 million compared to $6.9 million in the same ... 2016 was $0.6 million compared to $2.6 million in the ... of 2016 was $0.5 million, or $0.02 per diluted share, ...
Breaking Biology News(10 mins):
(Date:3/22/2017)... ... , ... The Society for Immunotherapy of Cancer (SITC) strongly opposes the proposed ... fiscal year 2018 budget request. , This proposal calls for a ... roughly 20% of its total budget. If applied proportionally across NIH, funding for the ...
(Date:3/22/2017)... , March 22, 2017  RXi Pharmaceuticals ... innovative therapeutics that address significant unmet medical needs, ... Chief Business Officer, will present at the 5th ... will provide a platform to present to and ... leading pharmaceutical and biotech companies as well as ...
(Date:3/20/2017)... ... March 20, 2017 , ... ... and biotech companies, recently announced it will debut a brand new pressure vessel, ... The intelliVessel is controlled by a touch screen panel and features other revolutionary ...
(Date:3/20/2017)... , ... March 20, 2017 , ... The fourth annual ... while innovating to make an extraordinary impact on peoples’ lives, launches today. Sponsored by ... challenge every 5 weeks and awards thousands in cash prizes to engineers, inventors and ...
Breaking Biology Technology: