Electrical devices 'disrupt bird navigation' Skip to main content

Electrical devices 'disrupt bird navigation'

Electrical devices 'disrupt bird navigation'
Rebecca Morelle By Rebecca Morelle Global science correspondent, BBC News
Robin The researchers found the navigational skills of European robins were thrown off course by weak radio waves

Related Stories

Electrical devices may disrupt the migration of some birds, a study suggests. 

A German team has found that weak electromagnetic fields produced by equipment plugged into mains electricity and AM radio signals interfere with the animals' "internal compass".

They believe the effect is greatest when birds fly over urban areas.

The study is published in the journal Nature.

Prof Henrik Mouritsen, from the University of Oldenburg in Germany, who carried out the research, said: "At first, I was highly sceptical that this could be the explanation.

"But if you have seemingly unlikely effects then the proof needs to be much stronger - and that is why we have done so many experiments over seven years and it has taken a long time before we were confident to come out with this to the public."

Surprise discovery
Some birds perform remarkable feats of navigation, migrating half way around the world.

“Start Quote

They have their different compasses: a star compass, a sun compass and a magnetic compass”
Prof Henrik Mouritsen University of Oldenburg
It is thought that a built-in magnetic compass, which senses the Earth's magnetic field, helps them to find their way.

Prof Mouritsen told BBC News he stumbled across the fact that low frequency waves could be interfering with this by accident while studying European robins.

"The basic experiment we do in bird navigation research is that we put birds into an orientation cage," he explained.

"They are so eager to migrate, that they will jump in the direction in which they want to fly, and if you turn a static magnetic field in the horizontal plane they will start to jump in a different direction.

"That experiment has worked for more than 40 years in a number of locations.

"But here in Oldenburg, we couldn't get that basic experiment to work until one day we got the idea to screen these huts on the inside with aluminium plates so the electromagnetic noise was reduced about 100 times.

"And suddenly the birds started to orientate."
Plug sockets When devices are plugged into the mains they produce a weak electromagnetic field
 
Over the course of the next seven years, he and his team carried out numerous experiments to look at how the weak electromagnetic field affected the behaviour of the robins.

In essence, he found that birds exposed to electromagnetic "noise" between 50 kHz and 5 MHz lost all sense of direction. But when the field was blocked out, they found their bearings again.

Prof Mouritsen said that migratory birds flying over towns and cities, where there are more homes and businesses that use electrical devices, would be most effected - and they would probably resort to back- up navigational systems.

"The birds wouldn't be completely lost because they have three different compasses: a star compass, a sun compass and a magnetic compass, and they work independently of each other. As long as it is clear they should be fine with their sunset compass or star compass."

“Start Quote

I would now like to see another independent group replicate this”
Joe Kirschvink California Institute of Technology
 
Scientists do not yet understand how a bird's magnetic compass works, but there is some evidence that they use the quantum phenomenon of electron spin to navigate.

"A very small perturbation of these electron spins would actually prevent the birds from using their magnetic compass," Prof Mouritsen said.

"The energies (of the electromagnetic field) are so low in intensity that any physicists will tell you they can't have an effect on a process based on conventional physics.

"Given this effect is real, we find it very difficult to come up with an explanation that is not quantum based."

Commenting on the research in the journal Nature, Joe Kirschvink from the California Institute of Technology (Caltech), said that for some time the field of magnetobiology had been viewed as "a stomping ground for charlatans".

He told the BBC: "The fringe of the fringe of this field is radio field sensitivity."

But he said that this study was "convincing" and "rigorous".

"I would now like to see another independent group replicate this and I would like to see why some other groups have found such dramatically different things," he said.

http://www.bbc.com/news/science-environment-27313355
Labels:

Comments

Post a Comment

Popular posts from this blog

Chronology of the Press in Burma

1836 – 1846 * During this period the first English-language newspaper was launched under British-ruled Tenasserim, southern  Burma . The first ethnic Karen-language and Burmese-language newspapers also appear in this period.     March 3, 1836 —The first English-language newspaper,  The Maulmain Chronicle , appears in the city of Moulmein in British-ruled Tenasserim. The paper, first published by a British official named E.A. Blundell, continued up until the 1950s. September 1842 —Tavoy’s  Hsa-tu-gaw  (the  Morning Star ), a monthly publication in the Karen-language of  Sgaw ,  is established by the Baptist mission. It is the first ethnic language newspaper. Circulation reached about three hundred until its publication ceased in 1849. January 1843 —The Baptist mission publishes a monthly newspaper, the Christian  Dhamma  Thadinsa  (the  Religious Herald ), in Moulmein. Supposedly the first Burmese-language newspaper, it continued up until the first year of the second Angl
Post a Comment
Read more

ARSA claims ambush on Myanmar security forces

Arakan Rohingya Salvation Army (ARSA) on Sunday claimed responsibility for an ambush on Myanmar security forces that left several wounded in northern Rakhine state, the first attack in weeks in a region gutted by violence. Rakhine was plunged into turmoil last August, when a series of ARSA raids prompted a military backlash so brutal the UN says it likely amounts to ethnic cleansing of the Muslim Rohingya minority. The army campaign sent some 650,000 Rohingya fleeing for Bangladesh, where refugees have given harrowing accounts of rape, murder and arson at the hands of security forces and vigilantes. Myanmar's military, which tightly controls information about Rakhine, denies any abuses and insists the crackdown was a proportionate response to crush the "terrorist" threat. ARSA have launched few attacks in recent months.  But the army reported that "about ten" Rohingya terrorists ambushed a car with hand-made mines and gunfire on Friday morning
Post a Comment
Read more

Thai penis whitening trend raises eyebrows

Image copyright LELUXHOSPITAL Image caption Authorities warn the procedure could be quite painful A supposed trend of penis whitening has captivated Thailand in recent days and left it asking if the country's beauty industry is taking things too far. Skin whitening is nothing new in many Asian countries, where darker skin is often associated with outdoor labour, therefore, being poorer. But even so, when a clip of a clinic's latest intriguing procedure was posted online, it quickly went viral. Thailand's health ministry has since issued a warning over the procedure. The BBC Thai service spoke to one patient who had undergone the treatment, who told them: "I wanted to feel more confident in my swimming briefs". The 30-year-old said his first session of several was two months ago, and he had since seen a definite change in the shade. 'What for?' The original Facebook post from the clinic offering the treatment, which uses lasers to break do
1 comment
Read more