Turtles offer navigation clues
New research shows that loggerhead turtles have an internal compass that allows them to sense exactly where they are as they navigate long distances across open water.
Birds, fish and many other creatures are believed to pick up on changes in the Earth’s magnetic field to determine their north and south location along lines of latitude. But evidence of longitudinal east and west positioning from magnetic cues has never been seen in an animal before.
Understanding how loggerhead turtles achieve the feat could lead to new developments in navigational technology, say the researchers, whose report is published in the journal Current Biology.
Early human navigators solved the longitude problem using accurate clocks to compare times in different locations with reference to the Sun.
By monitoring the Earth’s magnetic field, the turtles can plot both their north-south and east-west position. They use this ability on long transatlantic migrations that last several years.
The University of North Carolina scientists investigated turtles’ navigational powers by simulating magnetic conditions at opposite ends of the Atlantic Ocean.