Reptiles
Flatback Turtle
Natator depressus · also called flatback sea turtle
Every other sea turtle species crosses borders and often entire oceans over the course of its life. The flatback turtle does not. It hatches on a remote northern Australian beach, spends its whole life foraging the shallow, muddy waters of Australia’s continental shelf, and returns to nest on Australian sand alone, an entire species content to stay within one country’s coastline.
Overview
The flatback turtle, Natator depressus, is a sea turtle found only in Australian and nearby waters. Its flatter, smoother shell and preference for shallow continental shelf habitat over open-ocean migration set it apart from every other sea turtle species.
Fewer eggs, bigger hatchlings
Where most sea turtles lay large numbers of smaller eggs, the flatback lays fewer, noticeably larger ones, producing bigger hatchlings that may face reduced risk from some of the smaller predators waiting on the beach and in the shallows immediately after emergence.
Status
Data Deficient — its entirely Australian range has meant less comprehensive long-term monitoring than several other, more widely distributed sea turtle species.
Flatback Turtle: common questions
Why is the flatback turtle unique among sea turtles?
The flatback turtle is the only sea turtle species found in just one country, nesting solely on beaches in northern Australia and largely restricting its foraging range to Australian continental shelf waters, unlike every other sea turtle species, which typically nest and forage across multiple countries and often across entire ocean basins.
Does the flatback turtle migrate across the open ocean like other sea turtles?
No, unlike several other sea turtle species known for long-distance migrations across open ocean, the flatback turtle largely stays within the relatively shallow waters of Australia's continental shelf throughout its life, rarely venturing into deep offshore water far from the coast.
Why does the flatback turtle lay fewer, larger eggs than other sea turtles?
A flatback turtle typically produces fewer, notably larger eggs per clutch compared with most other sea turtle species, a reproductive strategy that results in comparatively large hatchlings, which researchers believe may face somewhat reduced vulnerability to certain smaller predators immediately after they emerge from the nest.
How is the flatback turtle's shell different from other sea turtles?
The flatback turtle has a noticeably flatter, smoother shell with more upturned edges than the shells of other sea turtle species, a distinctive shape reflected directly in its common name and one of the more straightforward physical features used to distinguish it from similarly sized sea turtle relatives.