Turtles seem to always know where "home" is, kind of like pigeons. Now, scientists have found that turtles will return home when released by researchers, even after they've spent a year away.
In this latest study, the researchers at James Cook University tracked 59 turtles. These turtles were released outside of the areas where they had been found along the Queensland coast. While they lost communication with the tracking devices on two of the turtles, they were able to track the rest correctly.
The research team found that even after a long absence, most of the captive turtles returned to their old homes. One of the turtles, which had been held for 500 days while it recovered from an injury, was also able to find its way home. In addition, one turtle was released about 117 km from where it was originally found. Even with this challenge, it found its way.
"It was surprising, we weren't quite sure if they would make it back over that distance or after that amount of time," said Takahiro Shimada, lead author of the study who helped track the turtles.
What was really interesting was the precision with which the turtles managed to navigate. Most of the turtles ended up within just a few hundred meters of their original homes.
The researchers also returned another 54 turtles directly to their original homes in order to see if the turtles needed to "travel" before finding home. However, these turtles actually didn't leave the locations where they were placed, showing that the turtles recognized that they were home.
But how did the turtles navigate so well? The scientists believe that the animals navigate with the help of geomagnetic cues, rather like what pigeons use. They also believe that turtles may rely on other processes that are not yet fully understood.
These results are important for the conservation of turtles in the long-term. They show that placing turtles in another location due to the fact that their old homes have been damaged or have become dangerous is actually not an option. Instead, the areas where turtles currently live should be protected.
The findings were published in the January 2016 issue of the journal Marine Biology.
