Hawksbill turtles have “crude” migration systems, often travelling more than twice the required distance to their intended locations, according to new research appearing in the Journal of the Royal Society Interface.
For their paper, a team of scientists tracked 22 turtles via satellite as they swam “relatively short” distances. Only four turtles took direct routes.
“Turtles typically travelled twice (and in one case seven times) the direct distance to their target,” an excerpt from the paper reads.
“For example, one individual travelled 1306.2 km when the beeline to the foraging site was only 176.4 kilometres.”
In some instances, turtles travelling to nesting sites gave up after “long and protracted” searches, returning instead to foraging sites.
Turtles do not typically forage for food and nest in the same location, often migrating from foraging grounds to mating grounds, to nesting spaces.
Previous research suggests turtles may imprint on the geomagnetic field of their birthplace, later using it as a navigational tool to guide them back during nesting season.
Professor Graeme Hays, the study’s first author and chair in marine science at Deakin University, told The Guardian that while the turtles are “almost certainly” using a geomagnetic map, “it’s a fairly coarse resolution.”
“It doesn’t allow pinpoint straight-line migration, but it does tell them when they’re getting a long way off route,” he added.
As the turtles get closer to their target, researchers believe they rely on other cues – like smells and visual landmarks.
Given their crude sense of direction and the fact that hawksbill turtles typically migrate to small and remote locales, it’s a wonder they find their way at all.
Thumbnail: Getty Images via Canva Pro.