The computation of longitude was one of the great scientific challenges of the 18th century . Veryvaluable prizeswere offered for its answer , while countless sailors die from the wait . Yet birds solve the problem millions of years ago . Their solution , at least for reed warblers , has now been revealed as measuringmagnetic declination – the slant between magnetic north and truthful north – as well as the more wide used vividness and inclination .
Calculating parallel of latitude is a comparatively soft task , since ( much to theannoyanceof flat earthers ) different stars can be visit depending on the distance from the equator . Longitude is much operose , and prior to GPS required veryaccurate clocksthat could liken local time with that at a known location .
As a new paper inCurrent Biologynotes : “ Birds do not seem to possess a time - difference clock sense . ” Despite this , some make do to go on east - west migration , as well as the more common N - south I , home in on specific web site . Moreover , the paper says “ dark - migratory songbird can correct for east - west displacements to unknown locations . ”
The author catch 15 reed warblers ( Acrocephalus scirpaceus ) in westerly Russia on their fashion to Africa . These were placed inside a charismatic field with the same strength as that of the Earth locally , but a descent differ by 8.5 degrees . The artificial theatre of operations mimicked that near Edinburgh . The birdie respond as if they were indeed now in Scotland , turn 151º to vaporize eastern United States - south - east , rather than west - south - west .
" We ’ve shown for the first clip that charismatic decline may be a constituent of the magnetic navigational mapping , at least in some long - space migratory bird , " saidDr Nikita Chernetsovof the Zoological Institute of the Russian Academy of Sciences , in astatement .
The research also disclose a learned component . Twenty - five birds too young to have undergo a migration through Western Europe became disordered on picture to the adapted field , trying to flee in random directions .
" Reed warbler seem to learn the large - scale spacial pattern of the declination slope during their one-year apparent motion , just like they learn other gradients , inclination , and total intensity , " Chernetsov said . " As magnetic declination principally deviate along the east - west axis , it provides the possibility to measure longitude . "
Unresolved questions include how reed warblers understand the implications of a gradient from a positioning they have never experienced , and whether all migrant birds use the same proficiency . The discovery could have been of cracking use to navigator in previous C , who might have find reach that could measure magnetic declination easy to make than clocks that would keep time on a rolling ship . Nevertheless , it is not clear if there are any technological covering for which it could be used today .
