Not suitable for pilots or air freight purposes: For a longtime, it was merely assumed that migratory birds navigated their journeys using magnetic field's . Satellite images and a newtool allow, for the first time, the strength and direction of the magnetic field to be correlated along their flightpaths.
Draft animals manage to cross entire oceans and continents andaccuracy the navigate. Despite decades of research, actual process is still not clear – although it has been suggested that the Earth's magnetic field lines are among the clues that guide them.
Recent advances in GPS and the miniaturization of tracking devices have enabled ecologists to tag migratory animals, from birds to whales, to understand how they travel from point A to point B. Although animal tracking data is now commonplace, little research has been conducted on how animals respond to real-world geomagnetic conditions—especially since the magnetic field is constantly changing globally, particularly during geomagnetic storms.
Until recently, there was no way to accurately determine the strength of the magnetic field at the time and place animals passed by. Using measurements from the ESA mission "Earth Explorer Swarm," scientists have developed a new program the strength and direction of the magnetic field with the flight paths of migratory birds correlates.
The new tool was developed by geodata scientists at the University of St Andrews in Scotland, in collaboration with researchers from the British Geological Survey and the University of Western Ontario in Canada. It combines data from the ESA magnetic field mission with data a "stored afreely accessible database containing millions of locations and times of birds, mammals, bats, and whales on the move. The study, recently published in Movement Ecology, explains how the values were calculated and provides examples of greater white-fronted geese flying from Siberia to Germany on their autumn migration.
Urška Demšar from the University of St Andrews: “We used the time and GPS positions of the animal to find the nearest swarm data. This then allows us to calculate the expected magnetic field at the animal's location based on the magnetic field generated by the Earth's core, taking into account the local influence from the geology and the current effect of the ionosphere and magnetosphere.”
Images: ESA
"These contributions were summed and appended to the GPS data, including swarm measurements from the next satellite overflights for each GPS location. This allows us to estimate the magnetic field at ' as accurately as possible."
The results meannow combine tracking data with geophysical information and lead to new insights into migration behavior can.
Inthe "Movement Ecology Paper," shows that geese were influenced and largely deviated from their direct northward migration route. that this example Urška Demšar says yet be generalized, but it demonstrates to study animal migrations using real magnetic data could now be used.
“This is the first direct use of swarm data in ecology and thus represents an exciting new avenue of research between geophysicists, geodata scientists and ecologists,” adds Ciarán Beggan of the British Geological Survey.
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