The easiest way to find the angle of declination is to check your map: most have declination diagrams, along with the date it was last revised. Because declination changes over time, newer maps ...

USGS topographic maps, National Geographic/Trails Illustrated maps, AMC trail maps and the like are all oriented with true north at the top of the map. Each also shows a declination diagram in its ...

Reed warblers have a sense for magnetic declination Date: August 17, 2017 Source: Cell Press Summary: Researchers recently showed that migratory reed warblers depend on an internal geomagnetic map ...