Two green sea turtles with satellite trackers were released off the coast of Australia ten weeks ago. One of these took off nearly immediately and flew east for 47 days, practically directly to Tonga. Then she abruptly turned around and nodded her way out of there. The Hunga Tonga-Hunga Ha’apai volcano erupted the next day, causing a tsunami and ash rain that wreaked havoc on adjacent islands. Its “speculative,” according to Jennifer Gilbert of the Cairns Turtle Rehabilitation Center (CTRC), to say that Tilly the turtle knew what was coming, but the map of her voyage doesn’t appear to be a coincidence.
Furthermore, a tiny earthquake rocked north Queensland while she was returning to the Great Barrier Reef. It wasn’t powerful enough to do damage, but it coincided with Tilly’s path being diverted once more. Gilbert told IFLScience, “I’m planning to do an observational paper.” “There has never been anything done before on turtles and seismic sensing.” On the other hand, research on the abilities of whales, dolphins, seals, and even goats to detect seismic activity before it occurs have been published, so Tilly may have had some faster company on her return journey, according to Gilbert.
Tilly’s career shifts are the latest twist in a life story worthy of a movie. Most turtles never hatched, according to volunteers who checked the success rate of a turtle nest. Others made it out of the nest for the scary rush to the sea depicted in a thousand nature documentaries. Two green sea hatchlings, on the other hand, were weary from their failed attempts to scramble up from the bottom and would have perished if it hadn’t been for human assistance. Tilly and Sammy were given names at CTRC, but Gilbert told IFLScience that sex cannot be determined until they are at least 20 years old. “For a while, it was quite touch and go” whether the couple would live, Gilbert told IFLScience. Both eventually prospered.
Normally, rescue turtles are released when they reach 45 centimeters (18 inches) in length, but COVID-19 had hampered travels to the continental shelf, where rescue turtles are released, by that time. The turtle twins were three years old and significantly larger by the time they were released, allowing the CTRC to equip them with more powerful trackers. Gilbert hoped this would be scientifically beneficial even before the eruption. Sea turtles that make it through the shallows, aside from flatbacks, head towards the continental shelf, not coming close to shore until they are 5-10 years old. “They’re known as the lost years,” Gilbert explained. “We have no idea what they do then.”
Researchers had not anticipated a 3-year-old turtle heading directly across Deep Ocean in search of reefs thousands of kilometers away, rather than the much more accessible outer Great Barrier Reef. “There are a lot of predators in those seas,” Gilbert remarked. “We believe she was on her way to the Soloman Islands or New Caledonia, but we don’t know why.” Even in light of Aesop’s fable about Testudines’ astonishing territory-covering capacity, Gilbert was taken aback by Tilly’s achievement of 3,000 kilometers (1,800 miles) in 73 days. Unfortunately, 10 days after his release, Sammy’s tracker stopped operating, which could have been due to an equipment fault or an unpleasant shark encounter.
We don’t know whether other turtles were similarly foresighted because the CTRC had no other turtle trackers in the area at the time, and Gilbert noted the same was apparently true of other Australian research organizations, so we don’t know if other turtles were similarly foresighted. “I don’t think you could utilize turtles as a prediction mechanism,” Gilbert told IFLScience, “as much as it could have helped the people of Tonga to have known about the eruption when Tilly evidently did.” You can’t direct a turtle’s path or even foresee what they’ll do. They have their own thoughts.”
