'Barulho' eletrônico interfere em voo de pássaros
Electrical devices may disrupt the migration of some birds, a study suggests. A German team has found that electromagnetic fields produced by equipment and AM radio signals affect the animals' navigational systems. The study is published in the journal Nature.
Repórter: Rebecca Morelle
Some birds perform remarkable feats of navigation, migrating halfway around the world. And it’s thought that a built-in compass, which senses the Earth's magnetic field, helps them to find their way.
But this latest study suggests that low frequency waves produced by devices plugged into the mains electricity, could be interfering with this 'inner satnav'. Scientists found that migratory birds exposed to this electromagnetic noise lost all sense of direction. But when the field was blocked out, they found their bearings again.
Researchers believe electrical interference could be a particular problem when birds fly over urban areas. They think the birds are forced to switch to back-up navigational systems, staying on course using the sun and stars instead.
compass device to establish position which has a needle always pointing north
mains electricity system of wires which carries electricity into a house
satnav system of computers and satellites used to establish location
found their bearings discovered their exact position in their journey
back-up device or system kept as a reserve to be used if the main system fails or extra help is needed