Turtle hatchling on the beach

Quirky Eco Fact – Cool Guys and Hot Chicks

No, this article isn’t about beach babes and buffed blokes strutting their stuff on Australia’s Bondi Beach. This quirky Eco Fact is about marine turtles.

Did you know, that for marine turtle species the sex ratio and survival rate of hatchlings is determined by the temperature of the sand surrounding a nesting chamber?

The ideal temperature is where equal ratios of males and females are produced. For Queensland and Western Australia this is 29.3 (Limpus 2007) and 29.4 degrees Celsius (Stubbs et al 2014) respectively. Cooler temperatures (below 27 degrees Celsius) produce all males, and warmer temperatures (above 31.4 degrees Celsius) produce all females – cool guys and hot chicks. Few marine turtle hatchlings in Queensland have been known to survive temperatures above 34 degrees Celsius.Eco Beach turtle project monitoring

With climate change, and water and land temperatures rising, does this mean turtle populations are at risk? In 2012 Conservation Volunteers Australia compiled a report from turtle research at Eco Beach in Western Australia. The research found hatchlings had survived at higher temperatures – so is there more to the story? Ongoing monitoring programs will help complete the picture. In 2016 four temperature loggers were buried at Eco Beach to record sand temperatures at the depth flatback turtles lay their eggs. The loggers will be dug up in a few years to help researchers to understand the threats climate change may present to turtles.


About Flatback Turtles

Flatback turtles (Natator depressus) are the only sea turtles that spend their lives almost wholly within the Australian continental shelf. Flatback turtles are listed as ‘vulnerable’ in Western Australia under the Australian Government’s Environment Protection and Biodiversity Conservation Act 1999, and data deficient by the International Union for Conservation of Nature. In fact, the flatback is the only marine turtle species listed globally as “Data Deficient” meaning there is not enough information to tell whether flatback turtle populations are declining, stable or increasing.

Since 2008 Conservation Volunteers Australia has been collecting data on the nesting flatback turtle population at Eco Beach. Data gained from research projects contributes important information to the International Union for Conservation of Nature and helps determine the status and management needs of flatback turtles.

You can read more about the flatback turtle experience in the latest edition of Wildlife Australia Magazine. The magazine is Australia’s longest-running natural history magazine. Each issue showcases spectacular nature photography and riveting articles on a diversity of ‘wild’ topics. All magazine subscription proceeds go towards wildlife conservation. The magazine currently has a 50% off digital subscriptions offer.

About our naturalist guidesAnne o'dea and flatback turtle

Steve Winderlich and Anne O’Dea have over 25 years’ experience in natural and cultural resource management. They are passionate about marine and terrestrial protected areas and wildlife. Their experience includes running research and monitoring programs, volunteer engagement, education, interpretation and training. Steve and Anne have interesting stories to share having spent time working in National Parks including Fraser Island, the jointly managed Kakadu National Park and more recently Papua New Guinea. Anne also featured in the ABC Television Series – Kakadu. You can meet Steve and Anne on our Naturewise Sea Turtle Experience at Eco Beach.

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