Flatback sea turtle: where and when to see them

The flatback sea turtle is a distinctive marine reptile whose nesting range is confined to Australia. Its relatively low, broad shell has upturned margins and a softer-looking surface than those of many other sea turtles. Unlike species with widely dispersing oceanic young, flatbacks remain associated with continental-shelf waters throughout their life cycle. Nesting beaches therefore connect closely with regional coastal seas, where development, fishing interactions and disturbance can affect survival.

Size

80–95 cm carapace length

Weight

60–90 kg

Lifespan

Not reliably established

Status

Check current assessment

Females come ashore, usually at night, to excavate nests above the tide line and lay several clutches within a nesting season. Males remain at sea. Hatchlings emerge from the sand and move toward the water, relying partly on natural light cues. Adults can travel substantial distances between feeding and nesting areas, but do not follow the strongly oceanic juvenile pattern typical of several other sea turtles. Disturbance can interrupt nesting attempts. Females exhibit strong nesting site fidelity, often returning to the same beach or region to lay their eggs. The relatively short oceanic migration of flatbacks, compared to other species, suggests a life cycle closely tied to the continental shelf. Clutch sizes are generally smaller than those of other sea turtle species, but they can lay multiple clutches per season.

• All known nesting beaches are in Australia.
• Flatbacks lack the prolonged oceanic juvenile phase typical of most sea turtles.
• Their eggs and hatchlings are relatively large compared with those of other sea turtles.
• They are the only living species in the genus Natator.

Nesting timing varies substantially across northern Australia. Some southern Queensland rookeries are active mainly from November to January, while tropical northern sites can follow different schedules or have extended seasons. Select a locally managed viewing programme rather than applying one national nesting calendar. Peak nesting season often aligns with warmer water temperatures, which can vary regionally. Early dry season in the Northern Territory and late wet season in Queensland are typical high activity periods. Research indicates nesting can occur year-round in some northern locations, but with defined peaks.

Flatbacks occupy tropical and subtropical continental-shelf waters around northern Australia and nearby seas. Feeding areas include soft-bottom coastal environments, while nesting occurs on sandy Australian beaches and islands. Many rookeries are remote, culturally sensitive or accessible only through controlled arrangements. This species is endemic to the Australian continental shelf, rarely found outside its waters. They prefer turbid inshore waters over open ocean habitats. Juveniles also remain in these coastal environments, unlike the pelagic juvenile stage of many other sea turtles.

They feed mainly on soft-bodied marine animals, including sea cucumbers, jellyfish and sea pens, as well as other invertebrates. Prey is obtained in coastal shelf habitats. Their diet differs from the predominantly seagrass-based feeding typical of many adult green turtles. Their preference for soft-bodied prey means they play a distinct ecological role in coastal ecosystems. Flatbacks are opportunistic feeders, consuming a variety of organisms available in their shallow water foraging grounds. Their diet reflects adaptation to the specific invertebrate communities found in Australian shelf waters.

Common name

Flatback sea turtle

Scientific name

Natator depressus

Animal group

Reptiles

Size

80–95 cm carapace length

Weight

60–90 kg

Lifespan

Not reliably established

Status

Check current assessment

Identification

The low, broad olive-grey shell with upturned edges and four pairs of costal scutes distinguishes flatbacks from the more domed green turtle and five-paired loggerhead. The flattened carapace gives them a distinctive profile, aiding identification even from a distance. Their smooth, waxy-feeling carapace, often covered in algal growth, also helps distinguish them. Unlike other sea turtles, they lack an epidermal keel along their back.