The world’s oldest known tagged turtle has surprised scientists by returning to Bundaberg in Queensland for her 13th nesting season. (60-year-old flatback turtle) - via Herp Digest

Nov 30, 2015, Francis Adcock, The New Daily, Queensland, Australia  

A turtle tagged 39 years ago has returned to a Queensland beach for nesting season.

The 60-year-old flatback turtle has returned to Mon Repos.

The world’s oldest known tagged turtle has surprised scientists by returning to Bundaberg in Queensland for her 13th nesting season.

The flatback turtle, known by her tag number X23103, is estimated to be at least 60 years old and came ashore last week to lay a clutch of eggs.

Dr Col Limpus from the Department of Environment and Heritage Protection said she was the longest studied turtle in the wild.

“We tagged her (X23103) as she started her breeding season 39 years ago,” he said.

“She only comes to Mon Repos beach, she’s been recorded here 65 times in that 39 years.

“She doesn’t go to any other nearby beaches.”

Female flatback turtles may return to the shore every year, but they only lay eggs every two or three years.

Mon Repos visited by loggerhead, flatback and green turtles

They lay between one and four clutches, with about 50 eggs in each nest.

Flatbacks start to breed when they are about 20 years of age, Dr Limpus said.

“So that would make her approximately 60 years of age, give or take a year,” he said.

He said the turtle was teaching researchers about their longevity and their breeding capacity.

“No one’s ever followed turtles this long to know what they do,” he said.

“We often sit and think over a cup of coffee and wonder what happens in old age for them.

“What we think is old age for her, she’s still laying big clutches and she’s laying some of the biggest eggs for flatback turtles.

“We’ve got information on each breeding season and she typically lays well over the average size.

“She laid 61 eggs in the clutch the other night.”

Baby flatback turtles crawl through human footprints on their way to the ocean. Photo: AAP

Mon Repos is one of the world’s key study sites for sea turtles.

Loggerhead turtles, green turtles and flatbacks all nest at Mon Repos beach.

“There are very few places where the depth of data exists over so many years for any sort of sea turtle,” Dr Limpus said.

“It is teaching us quite a lot about the turtles as they age but it is also allowing us to keep track of what’s happening to our local populations.

“Are they recovering, are they staying stable, declining, those sorts of things.

“Our census data allows us to get counts on that sort of thing, then comparing across the years to identify issues that need to be looked at.”

Dr Limpus said the nesting season was progressing well.

“It doesn’t look like it’s going to be a worse season than last year.

“We haven’t yet reached the middle of the season so we can’t give precise estimates but it’s looking good.”

Queensland Parks and Wildlife Service said 49 endangered loggerhead and five flatback turtles had come to nest so far this season.

Last season, the beach was visited by about 410 loggerhead, 12 flatback and three green turtles.