Experiments using the common reed warbler showed they were sensitive to the difference between true north, the geographic North Pole, and magnetic north, a separate location in the Arctic Circle. In Europe, the difference increases from east to west, and the new study indicates warblers are able to sense this variation to determine where they are. The international team of researchers, including scientists from Bangor University, predict that this sensitivity is shared by many other species. It has long been believed that birds rely on the Earth’s magnetic fields to navigate their epic migrations, but precisely how they solve the longitudinal riddle has, until now, remained a mystery. “It seems that a bird as unassuming as the reed warbler, may have a geographic map or memory that enables it to identify its longitudinal position on the globe, only by detecting the magnetic north pole and its variance from true north,” said Dr Richard Holland, of Bangor University, who took part in the research.

Source: The North Africa Journal August 17, 2017 15:56 UTC