James Cook University researchers are fast gaining insights into the mysterious 'lost years' of loggerhead turtles as the reptiles mark their second birthday in Townsville.
13 of the species have been housed at JCU's Turtle Health Research Centre since 2022 as part of a three year, $150,000 project funded by Glencore to understand more about the little-known first years of a loggerhead turtle's life.
JCU Veterinary Sciences Academic Coordinator Jess Grimm said unlike their more docile green turtle cousins, the energetic loggerheads love a high protein diet and are not afraid to display some territorial behaviour.
"They're not aggressive, but they've got a lot of pep. They're a little feisty and bitey but in the wild they are the same, so it appears they are wired that way right from the moment they hatch out of the nest," she said.
"In the wild they will feed on things like molluscs and crabs, a very protein heavy diet. We feed them a mix of vegetables, protein and vitamins to make sure they're getting all the nutrients they need, but they've never really gone for the veggies alone unless we blend them into their food."
Identified by their spikey shell and reddish-brown texture, the loggerheads have grown rapidly over the past two years, weighing as little as 18g when they first arrived compared to a hefty 6- 9kg today.
Likewise, the length of the turtles' shells, or carapaces, has grown from 43-47mm to 300-400mm over the same period of time.
"They've grown much faster and are much thicker than other species of turtles we have raised," Ms Grimm said.
The long-term project is the first of its kind for loggerheads in the South Pacific, with researchers already benefitting from the insights the turtles are providing, such as analysing different enrichment devices in captivity and investigating the species' gut microbiome.
The turtles will remain at JCU for another year before they are fitted with satellite tracking devices upon their release back into the wild.
The devices will allow researchers to follow their movements through the ocean during their next stage of life.
JCU Marine and Aquaculture Sciences Senior Lecturer Professor Mark Hamann said the study was giving researchers a view into a part of the loggerheads' lives otherwise unseen in the wild, due to turtles of comparable size and age often swimming in the ocean far away between New Zealand and Peru.
Also known as the Caraplace, JCU's Turtle Health Research Centre is home to 39 volunteers and two researchers who study a variety of turtle species.
