ENIDDENL
Wildlife of Borneo

Green turtle

Chelonia mydas

Chelonia mydas is a hard-shelled sea turtle with a relatively small head and one pair of prefrontal head scales.

Least concern
Species details & taxonomy
Species
Chelonia mydas
Genus
Chelonia
Family
Cheloniidae
Order
Testudines
Class
Reptilia
Green turtle (Chelonia mydas); see the caption for the photograph’s location.
Chelonia mydas in Hawaiʻi, USA; species portrait outside Kalimantan.Brocken Inaglory · Wikimedia Commons · CC BY-SA 3.0 · Original

Recognition

Chelonia mydas is a hard-shelled sea turtle with a relatively small head and one pair of prefrontal head scales. Its shell can appear brown, grey or olive; the common name is not a reliable shell-colour test. The species occupies tropical and subtropical seas far beyond Borneo.

Sources & references · 1NOAA Fisheries · Green turtle

Forest and water

Early life includes open-water stages, followed by coastal feeding areas and migrations between feeding and nesting sites. A nesting beach and a feeding reef serve different functions; evidence at one does not describe the animal’s entire journey.

Sources & references · 1NOAA Fisheries · Green turtle

Food and foraging

Adults feed mainly on seagrasses and algae; young turtles have a broader diet that includes animal foods. This life-stage difference matters when interpreting photographs of turtles near reefs.

Sources & references · 1NOAA Fisheries · Green turtle

Breeding

Females lay eggs on sandy beaches. Incubation and hatchling emergence depend on local conditions, so a historic nesting study is not a fixed visitor calendar.

Sources & references · 1NOAA Fisheries · Green turtle

Range and local records

The selected sources document Chelonia mydas at Derawan Island, Berau. These are place-specific published records, not current population estimates or evidence for every protected area in the province.

Sources & references · 1Dharmadi and Wiadnyana / Indonesian fisheries research journal · Habitat dan sebaran sarang penyu hijau di Pulau Derawan

Conservation outlook

The 2025 global assessment is Least Concern. This does not remove regional threats, nesting-site sensitivity or Indonesian protection; older global Endangered labels should not be reused as if current.

Sources & references · 1IUCN SSC Marine Turtle Specialist Group · Sea turtle conservation statuses

A local nesting rhythm

Sabah Parks reports green turtles nesting throughout the year, with a July–October peak at Turtle Islands Park. Females dig above the high-water line using their rear flippers. Bright lighting can deter arrivals. Sand temperature influences offspring sex, which makes shade and nest conditions important aspects of hatchery management.

Sources & references · 1Sabah Parks · Turtle Islands Park: Turtle Conservation

Where to look

A recorded occurrence does not guarantee a sighting or visitor access. Read the area and experience guides for habitat, responsible observation, guiding and current access before choosing a trip. Keep wildlife at a distance and follow local restrictions.

Places with documented occurrence

Related wildlife trips

Related discoveries

Habitats

Nature areas

Coastal view on Derawan Island; this photograph shows the island setting, not an underwater reef.
Nature areas

Derawan coastal and island conservation area

The Derawan conservation seascape lies off Berau in East Kalimantan, linking island shores with reefs and coastal waters. It is larger than Derawan Island and is not a national park. Its value comes from connected marine habitats: an island beach, reef slope and surrounding waters are different parts of the same system. Visitors normally experience selected sites through an island base and a boat operator, rather than entering one bounded park gate. Choose the actual island and marine activity before arranging transfers. Some areas have conservation restrictions, and a tourism description of the archipelago does not establish unrestricted access to every reef, beach or turtle nesting site.

Riza Nugraha · Wikimedia Commons · CC BY 2.0 · Cropped · Original
Rambungan River mouth with Satang Kecil and Satang Besar islands in the distance, photographed in 2023.
Nature areas

Talang-Satang National Park

Talang-Satang National Park protects turtle nesting islands and surrounding marine habitats off western Sarawak. It is a conservation area with a limited visitor component, not a group of freely accessible holiday islands. The distinction between islands is essential: Sarawak Forestry allows ordinary day visits to the designated part of Pulau Satang Besar, while the Talang islands and other sensitive sites have separate restrictions. A visit can introduce the relationship between nesting beaches, coral communities and the wider sea, but it should not be sold as a guaranteed turtle encounter. Arrange the boat and permission context in advance, remain with the wardens where required and accept that marine conditions may change the programme. Mainland accommodation is the appropriate default for a normal day visit; specialist conservation participation is a different arrangement, not a way around visitor restrictions.

Cerevisae · Wikimedia Commons · CC BY-SA 4.0 · Cropped · Original

Destinations

Coastal view on Derawan Island; this photograph shows the island setting, not an underwater reef.
Destinations

Derawan Island

An inhabited island off Berau, Derawan is a visitor base within a much wider reef-and-island seascape. Its documented green-turtle nesting makes respectful coastal visits especially important. Three nights is a useful starting point for arrival, one or two sea days and time in the inhabited island setting. Longer stays give more flexibility for sea conditions and a less hurried pace. Choose Guided snorkelling around Derawan around your swimming or diving ability and the actual site proposed, rather than buying a list of island names. A short snorkelling outing and an all-day boat circuit ask different things of the weather, equipment and traveller.

Riza Nugraha · Wikimedia Commons · CC BY 2.0 · Cropped · Original
Sekonyer River in Tanjung Puting National Park, Central Kalimantan.
Destinations

Kalimantan

Kalimantan is the Indonesian part of Borneo, where five provinces invite five different starting decisions. Choose rivers and peat forests around Palangka Raya or Pangkalan Bun, city food and upper-Kapuas journeys in the west, Banjar river life and Meratus hills in the south, Mahakam heritage and Berau islands in the east, or coastal and highland travel in the north. The most useful question is which corridor deserves your time, not how many provinces can fit on a map. Travel usually combines an arrival city with separate road, river or island stages. Use the province summaries below to choose a starting point, then open its destination and activity pages for the actual visit.

Nanosanchez · Wikimedia Commons · CC BY-SA 4.0 · Cropped · Original
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Activities

Diving below Barracuda Point, Sipadan, photographed in 2010.
Activities

Diving around Sipadan

Sipadan is a marine diving destination where reef structure and deeper water meet close to an oceanic island. For trained divers, the attraction is time underwater along reef edges and walls, watching how fish and larger marine animals use a changing three-dimensional environment. A visit is normally organised through an authorised dive operator, with accommodation elsewhere in the Semporna island area or on the mainland. That makes the permit allocation and dive arrangements the starting point of planning, rather than simply travelling to the island and expecting to buy a dive. This activity suits divers who want a focused marine day within a longer Sabah itinerary and who are prepared to match their experience to the operator's assessment of the sites and current conditions.

Chen Wu from Shanghai, China · Wikimedia Commons · CC BY 2.0 · Cropped · Original
Coastal view on Derawan Island; this photograph shows the island setting, not an underwater reef.
Activities

Guided snorkelling around Derawan

Around Derawan, a reef visit begins where the island's shoreline gives way to shallow marine habitat. With a suitable local boat and guide, snorkelling offers a way to look closely at reef fish, coral formations and the changing colour of the water without undertaking a scuba-diving programme. Staying on or near the island lets you choose outings around local sea conditions instead of making the water visit the hurried end of a long transfer. This activity is best understood as a guided reef experience within the Derawan island setting, not a promise to visit every named island in the archipelago in one day. It suits confident swimmers interested in marine life and travellers who want a few focused hours in the water between slower periods ashore.

Riza Nugraha · Wikimedia Commons · CC BY 2.0 · Cropped · Original

Sources & references

Sabah Parks · Turtle Islands Park: Turtle ConservationAccessed: 2026-10-04

Dharmadi and Wiadnyana / Indonesian fisheries research journal · Habitat dan sebaran sarang penyu hijau di Pulau DerawanAccessed: 2026-10-01

NOAA Fisheries · Green turtleAccessed: 2026-10-01

IUCN SSC Marine Turtle Specialist Group · Sea turtle conservation statusesAccessed: 2026-10-01

Sabah Parks · Turtle Island Heritage Protected AreaAccessed: 2026-10-02

Sarawak Forestry Corporation · Talang Satang National ParkAccessed: 2026-10-02

Universiti Malaysia Sarawak · Seaweed Halimeda spp. of Satang Island, SarawakAccessed: 2026-10-02

Universiti Malaysia Sarawak · Research Update Vol.5 No.2 December2009 — Molecular phylogeny of green turtle Chelonia mydas in Talang-Satang National ParkAccessed: 2026-10-02

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