Why our birds, bees and wildlife are dying

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Why our birds, bees and wildlife are dying

EXCERPT:  Pointing at the EMR noise pollution in our environment

US and German scientists have shown that oscillating magnetic fields disrupt the magnetic orientation behaviour of migratory birds (Ritz T et al. ‘Resonance effects indicate a radical-pair mechanism for avian magnetic compass’, Nature 2004, May 13, Vol 429, p. 177). Migratory birds are known to use the geomagnetic field as a source of compass information and there are two competing hypotheses for the primary process underlying the avian magnetic compass, one involving magnetite, the other a magnetically sensitive, chemical reaction (see links below).

The researchers found that robins were disoriented when exposed to a vertically aligned, broadband (0.1-10 MHz) or a single-frequency (7-MHz) field in addition to the geomagnetic field. In the 7-MHz oscillating field, this effect depended on the angle between the oscillating and the geomagnetic fields. The birds exhibited seasonally appropriate, migratory orientation when the oscillating field was parallel to the geomagnetic field, but were disoriented when it was presented at a 24- or 48-degree angle.

The authors state that their results are consistent with a resonance effect on singlet-triplet transitions and suggest a magnetic compass based on a radical-pair mechanism. They comment:

‘The magnetic compass of birds is light-dependent and exhibits strong lateralization with input coming primarily from the right eye. However, the primary biophysical process underlying this compass remains unexplained. Magnetite, as well as biochemical radical-pair reactions have been hypothesized to mediate sensitivity to Earth-strength, magnetic fields through fundamentally different physical mechanisms.’

In the magnetite-based mechanism, magnetic fields exert mechanical forces. In the radical-pair mechanism, the magnetic field alters the dynamics of transitions between spin states, after the creation of a radical pair through a light-induced electron transfer. These transitions in turn affect reaction rates and products. Although in most radical-pair reactions the effects of Earth-strength magnetic fields are masked by a living system’s background ‘noise’, model calculations show that such effects can be amplified beyond the level of background ‘noise’ in specialized, radical-pair receptor systems.

Alasdair Philips (Powerwatch) comments:

‘The support for a possible mechanism is interesting. However, medium- and short-wave frequencies have been used since the 1930s with little evidence of any effect on bird behaviour. But since the mobile phone networks went up there have been increasing reports of birds, especially homing pigeons, getting lost. Research now needs to look at the effects of base station signals, particularly in view of the disorientating effects of EMR ‘noise’ reported in this study.’

http://www.hese-project.org/hese-uk/en/issues/nature.php

 

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