- Where
- Indian Ocean, about 350 km south of Java
2,600 km north-west of Perth - Coordinates
- 10.4900° S
105.6275° E - Area
- 135 km²
(Wikipedia) - Highest point
- Murray Hill, 361 m
- People
- 1,692 (2021 census)
- Protected
- 63% national park (since 1980)
- Getting there
- QantasLink from Perth
about five hours, with a stop - Best visited
- Year-round; red crab migration usually October to December
The road had turned red, and it was moving: crabs past counting, each as broad as my palm, clicking across the tarmac toward the sea while a ranger waved the cars around. Up in the tall forest the rain had only just arrived, warm and heavy, and still more crabs came walking out of it. I went along on tiptoe, apologising to everybody.
The short answer
Christmas Island, officially the Territory of Christmas Island, is an Australian external territory in the Indian Ocean, about 350 kilometres south of Java and Sumatra and 2,600 kilometres north-west of Perth, by Wikipedia’s figures; its closest point on the Australian mainland is Exmouth, 1,550 kilometres away. The island covers 135 square kilometres. It is the summit of an underwater mountain more than 4,500 metres high, a former volcano capped by limestone from coral, and its steep coastal cliffs rise to a central plateau that reaches 361 metres at Murray Hill. Most of it is tropical rainforest, and 63 per cent is Christmas Island National Park. It had 1,692 residents at the 2021 census, most in settlements on the north coast around Flying Fish Cove. It shares its name with Kiritimati, in Kiribati, a different island in the Pacific.
Why it's worth knowing
The march of the red crabs. The Christmas Island red crab lives only here and on the Cocos (Keeling) Islands, Wikipedia records. For most of the year the crabs keep to burrows on the forest floor. The start of the wet season, usually in October or November, sets off their migration to the coast, timed with the phases of the moon: the males arrive first and dig burrows, mating follows, and the females, after about two weeks incubating their eggs, release them into the sea at the turn of the high tide in the moon’s last quarter. The larvae spend three to four weeks at sea, and the young crabs, about five millimetres across, walk back inland. During the migration the authorities close and divert roads. Parks Australia’s staff put up temporary barriers along the roadsides to funnel the crabs into tunnels under the roads and over a crab bridge, by the national park’s own account in indexed text.
How many crabs there are depends on the count. Wikipedia’s article on the species gives an estimate of 43.7 million adult red crabs on the island at one time, and says the yellow crazy ant, an invasive species accidentally introduced, is believed to have reduced the population by about a third. Its article on the national park speaks of around 100 million crabs moving to the sea in the migration, and the park’s staff, in indexed text, of tens of millions. Each figure is given here with its source; none is the official count.
The field notes
A forest of rare birds
Christmas Island National Park was established on 21 February 1980 after concern about the effect of phosphate mining on the island’s wildlife, above all on the habitat of Abbott’s booby, and was extended in 1986 and 1989 to take in most of the rainforest, Wikipedia records. The island is the only nesting place of the endangered Abbott’s booby and of the critically endangered Christmas Island frigatebird. It also holds what Wikipedia calls the world’s largest population of coconut crabs, the largest land invertebrate, possibly as many as a million. Two of the park’s wetlands, The Dales and Hosnies Spring, are Ramsar sites.
Named on a feast day, settled for phosphate
Captain William Mynors of the East India Company ship Royal Mary named the island when he sailed past on Christmas Day 1643. It was settled only in the late nineteenth century, after deposits of phosphate were found, which led Britain to annex it in 1888 and begin mining in 1899, Wikipedia records. Japan occupied the island in 1942 for its phosphate. After the war it was administered from Singapore until it was transferred to Australia in 1958. The people of the island, of Chinese, Malay and European descent among others, speak English, Malay and several Chinese languages; Wikipedia notes Buddhism in Poon Saan, Islam in the shoreline Malay kampong and Catholicism in the main settlement. The island also has an immigration detention centre at North West Point; AAP reported that the Australian government emptied it in October 2023 and kept it in what the Australian Border Force called a “hot contingency” state.
Red crabs crossing a forest track on the migration to the sea, December 2009.
Photograph: Ian Usher · Christmas Island Crabs on annual migration · CC BY-SA 3.0 · cropped
A red crab on a forest path at Margaret Knoll, April 2011.
Photograph: John Tann · Gecarcoidea natalis 2 · CC BY 2.0 · cropped
A strangler fig's buttress roots on the forest floor, April 2011.
Photograph: John Tann · Strangler fig (5731429030) · CC BY 2.0 · cropped
Flying Fish Cove at dusk, August 2017.
Photograph: Paul McFarlane · Flying Fish Cove · CC BY-SA 2.0 · cropped
- When the road ahead turns red, stop the car and wait. The crabs are not going to be the ones who give way.
- Start counting crabs at breakfast, then give it up, with dignity, before lunch. The list records the attempt and no figure.
- Ask each morning which roads are shut, and let that answer, not the map, decide the route.
- The temples along the shore are in daily use. Go in quietly, leave your shoes where others have left theirs, and give a little if there is a box.
- On a night when the crabs are spawning, stand above the shore after dark and watch the waves along the rocks. Something will change in them.
The crab bridge. A bridge about five metres high over one of Christmas Island’s roads, built so that red crabs on their way to the sea can climb up one side and down the other while the traffic passes underneath, as ABC News reported in December 2015. Each wet season the national park’s staff put up temporary barriers along the roadsides to steer the crabs to it and to the tunnels beneath the roads. It is seen from the road, and crossed only by crabs.
Tally, in the marginI waited beside it a good while to see which cars would use it. Then a crab climbed over it from one end to the other without a single glance my way. It took that crab to show me whose bridge it was.
Getting there
How to get there. By air from Perth. QantasLink has flown Perth to Christmas Island and the Cocos (Keeling) Islands since 3 November 2025, taking over from Virgin Australia, Qantas announced; its Monday flight leaves Perth in the morning and reaches Christmas Island in the early afternoon, local time, after a stop at Port Hedland, and goes on to the Cocos (Keeling) Islands. The territory’s administrator has published additional return flights to Christmas Island on set dates through 2026. Cars can be hired on the island, and some beaches are reached only by four-wheel drive and a walk through the forest, Wikipedia notes.
When to go. Any time of year. The dry season runs from July to October and the wet season from November to June, Wikipedia records, with cyclones possible in the wet. The red crab migration begins with the first heavy rain of the wet season, usually in October or November, and the spawning falls around the last quarter of the moon; Parks Australia publishes its predicted dates each year. Seas are roughest from December to March, the “swell season”.
What to arrange ahead. Flights, which are few, and a bed and a hire car, both limited on a small island; book early for the migration. During the migration, check each day which roads are closed.
Safety. The State Department has Australia at Level 1, exercise normal precautions, its lowest level, with no areas singled out (feed dated 30 May 2025, read 5 October 2026); its feed does not name the external territories. The hazards here are the place’s own: tropical cyclones in the wet season, steep cliffs, swell, and rockfalls and landslides around Flying Fish Cove, for which the territory’s administration published an updated landslide risk plan in February 2026.
Mark this place
Common questions
Where is Christmas Island?
Christmas Island is an Australian external territory in the Indian Ocean, about 350 kilometres south of Java and 2,600 kilometres north-west of Perth, Western Australia. It covers 135 square kilometres. It is not Kiritimati, also called Christmas Island, which is in Kiribati in the Pacific.
What is the Christmas Island red crab migration?
Each year at the start of the wet season, usually October or November, the red crabs of Christmas Island leave their forest burrows and walk to the coast to mate and spawn, timed with the moon. The females release their eggs into the sea at the turn of the high tide in the moon’s last quarter, and the authorities close and divert roads to let the crabs cross.
How many red crabs live on Christmas Island?
Estimates differ. Wikipedia’s article on the Christmas Island red crab gives 43.7 million adults at one time and says the invasive yellow crazy ant is believed to have cut the population by about a third; its article on Christmas Island National Park speaks of around 100 million crabs in the migration.
How do you get to Christmas Island?
By air from Perth, Western Australia. QantasLink has flown Perth to Christmas Island and the Cocos (Keeling) Islands since November 2025; the Monday flight stops at Port Hedland and takes about five hours to reach Christmas Island. The territory’s administrator has also published extra return flights on set dates in 2026.
Why is it called Christmas Island?
Christmas Island was named by Captain William Mynors of the East India Company ship Royal Mary, who sailed past it on Christmas Day 1643. Richard Rowe of the Thomas had sighted it earlier, in 1615.
What is the crab bridge on Christmas Island?
It is a bridge about five metres high, built over a road on Christmas Island so that migrating red crabs can cross it, ABC News reported in 2015. Each wet season Christmas Island National Park staff put up temporary barriers along roadsides to funnel the crabs to it and to tunnels beneath the roads.
How much of Christmas Island is national park?
About 63 per cent. Christmas Island National Park was established on 21 February 1980, after concern about phosphate mining’s effect on Abbott’s booby, and extended in 1986 and 1989 to include most of the island’s rainforest. It covers about 85 square kilometres.
Is Christmas Island part of Australia?
Yes. Christmas Island is an external territory of Australia. Britain annexed it in 1888, Japan occupied it in 1942, and after the war it was administered from Singapore until its transfer to Australia in 1958. It had 1,692 residents at the 2021 census.