A female loggerhead turtle makes her way to dry land to lay and bury her eggs in the sand. Photo by University of Queensland

Australia's monitor lizards, including the yellow-spotted goanna, are increasingly preying on the eggs of endangered sea turtles. Photo by University of Queensland

Dec. 14 (UPI) -- Feral foxes are no longer the archenemies of would-be loggerhead turtle moms at the second biggest nesting beach in northeast Australia. The title now belongs to the yellow-spotted goanna.

Over the last few decades, scientists have observed the Australia lizard develop a taste for the eggs of the endangered loggerhead turtle. Goannas now frequently raid turtle nests on the Queensland nesting beach.


To better understand the threat of Australia's monitor lizards to sea turtles, scientists at the University of Queensland set up camera traps near turtle nests. They watched for a year. The footage showed as many as 400 turtle nests disturbed by reptilian predators.

"We discovered that only large male yellow-spotted goannas dug open sea turtle nests, but once the nest was opened, other lizards, such as lace monitors and smaller yellow-spotted goannas, raided them," researcher David Booth said in a news release.

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Booth and his research partner Juan Lei, a doctoral student, published their analysis of the footage this week in the journal Austral Ecology.

"We had expected most nests would be discovered within one or two days of being constructed because of the visual and scent cues left behind by the female turtle," Booth said. "But what we found was the likelihood of a turtle nest being opened by a goanna wasn't related to the nest age or even the presence of ghost crabs, which disturb nests by burrowing and potentially releasing those smells that attract a goanna's attention."

Exactly how the goannas are locating the nests remains a mystery. Whoever is finding the nests are signaling their presence to a variety of predators.

Analyzing how predators looking for the same prey interact is important for understanding the workings of ecological systems, Booths said. Such an understanding could also help scientists better protect endangered turtles.

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