The sun compass

Schmidt-Koenig, Klaus

doi:10.1007/bf01952166

Cited by 84 publications

(51 citation statements)

References 21 publications

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“…ref. 13), there should be no effect of the power lines. Furthermore, highly significant alignment in localities without power lines (12) and the fact that the disturbing effect of the ELFMF attenuates with the distance from power lines clearly show that other factors possibly causing alignment, such as sunshine, wind direction, terrain conditions, herding instinct, or directional plant growth, play only a secondary role.…”

Section: Resultsmentioning

confidence: 99%

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Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants

Burda

Begall

Červený

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

100

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Resting and grazing cattle and deer tend to align their body axes in the geomagnetic North-South direction. The mechanism(s) that underlie this behavior remain unknown. Here, we show that extremely low-frequency magnetic fields (ELFMFs) generated by high-voltage power lines disrupt alignment of the bodies of these animals with the geomagnetic field. Body orientation of cattle and roe deer was random on pastures under or near power lines. Moreover, cattle exposed to various magnetic fields directly beneath or in the vicinity of power lines trending in various magnetic directions exhibited distinct patterns of alignment. The disturbing effect of the ELFMFs on body alignment diminished with the distance from conductors. These findings constitute evidence for magnetic sensation in large mammals as well as evidence of an overt behavioral reaction to weak ELFMFs in vertebrates. The demonstrated reaction to weak ELFMFs implies effects at the cellular and molecular levels.cattle ͉ magnetoreception ͉ roe deer ͉ power lines

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Section: Resultsmentioning

confidence: 99%

“…ref. 13) could not be excluded. We analyzed body orientations of ruminants in localities where the geomagnetic field is disturbed by high-voltage power lines to determine how local variation in magnetic fields may affect the previously described orientation behavior.…”

mentioning

confidence: 99%

Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants

Burda

Begall

Červený

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

100

View full text Add to dashboard Cite

show abstract

“…Compelling evidence for sun-compass orientation has also been provided by homing experiments with pigeons, Columba livia domesticus (reviewed in [11][12][13]). Vanishing bearings of homing pigeons, whose clocks were reset either clockwise or anticlockwise, were deflected relative to control birds in accordance with the direction and magnitude predicted by the use of a time-compensated sun compass (e.g.…”

Section: Are Polarized Light Cues Part Of the Avian Sun Compass?mentioning

confidence: 99%

Behavioural and physiological mechanisms of polarized light sensitivity in birds

Muheim

2011

Phil. Trans. R. Soc. B

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Polarized light (PL) sensitivity is relatively well studied in a large number of invertebrates and some fish species, but in most other vertebrate classes, including birds, the behavioural and physiological mechanism of PL sensitivity remains one of the big mysteries in sensory biology. Many organisms use the skylight polarization pattern as part of a sun compass for orientation, navigation and in spatial orientation tasks. In birds, the available evidence for an involvement of the skylight polarization pattern in sun-compass orientation is very weak. Instead, cue-conflict and cue-calibration experiments have shown that the skylight polarization pattern near the horizon at sunrise and sunset provides birds with a seasonally and latitudinally independent compass calibration reference. Despite convincing evidence that birds use PL cues for orientation, direct experimental evidence for PL sensitivity is still lacking. Avian double cones have been proposed as putative PL receptors, but detailed anatomical and physiological evidence will be needed to conclusively describe the avian PL receptor. Intriguing parallels between the functional and physiological properties of PL reception and light-dependent magnetoreception could point to a common receptor system.

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“…It is well known that birds can detect the Earth's magnetic field (reviewed by Wiltschko and Wiltschko, 1995) and use information from the sun (reviewed by Schmidt-Koenig, 1990), the skylight polarization pattern (Muheim et al, 2006a) and stars (Emlen, 1975) for orientation. Despite extensive research, however, the sensory mechanisms involved in avian magnetoreception are still not fully understood.…”

Section: Introductionmentioning

confidence: 99%

Zebra finches have a light-dependent magnetic compass similar to migratory birds

Pinzon-Rodriguez

Muheim

2017

Journal of Experimental Biology

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Birds have a light-dependent magnetic compass that provides information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina and mediated by a lightinduced, radical-pair mechanism involving cryptochromes as sensory receptor molecules. To investigate how the behavioural responses of birds under different light spectra match with cryptochromes as the primary magnetoreceptor, we examined the spectral properties of the magnetic compass in zebra finches. We trained birds to relocate a food reward in a spatial orientation task using magnetic compass cues. The birds were well oriented along the trained magnetic compass axis when trained and tested under low-irradiance 521 nm green light. In the presence of a 1.4 MHz radio-frequency electromagnetic (RF)-field, the birds were disoriented, which supports the involvement of radical-pair reactions in the primary magnetoreception process. Birds trained and tested under 638 nm red light showed a weak tendency to orient ∼45 deg clockwise of the trained magnetic direction. Under low-irradiance 460 nm blue light, they tended to orient along the trained magnetic compass axis, but were disoriented under higher irradiance light. Zebra finches trained and tested under high-irradiance 430 nm indigo light were well oriented along the trained magnetic compass axis, but disoriented in the presence of a RF-field. We conclude that magnetic compass responses of zebra finches are similar to those observed in nocturnally migrating birds and agree with cryptochromes as the primary magnetoreceptor, suggesting that light-dependent, radicalpair-mediated magnetoreception is a common property for all birds, including non-migratory species.

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The sun compass

Cited by 84 publications

References 21 publications

Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants

Extremely low-frequency electromagnetic fields disrupt magnetic alignment of ruminants

Behavioural and physiological mechanisms of polarized light sensitivity in birds

Zebra finches have a light-dependent magnetic compass similar to migratory birds

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