Christmas Island (23949)
Christmas Island (to Australia), Australasia
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1b, A1d, A1e, B1, B2, D1a, D3
Year of last assessment: 2025
National site name: Christmas Island
Central coordinates: Latitude: -10.4853, Longitude: 105.6362
System: terrestrial, marine
Elevation (m): 0 to 361
Area of KBA (km2): 140.10989
Protected area coverage (%): 62.92
KBA classification: Global
Legacy site: Yes
Site details
Site description: The KBA consists of the entire of Christmas Island and its surrounding coastal waters. It is located in the north-east Indian Ocean, approximately 2800 km west of Darwin and 360 km south of Java Head (Indonesia) and is administered as an Australian territory. The Island is 135 km2 of which 85 km2 (63%) is National Park. Christmas Island is the summit of a submarine mountain, with coastal cliffs rising steeply to a central plateau dominated by stands of rainforest. The climate is equatorial with a wet season (north-west monsoons) from December to April and a dry season (south-east trade winds) throughout the rest of the year.
Rationale for qualifying as KBA: This site qualifies as a KBA for eighteen trigger species including 10 birds, one insect, three land crabs, one mammal, two reptiles, and one species of plant. Three species are endemic and highly threatened (A1e) including the Christmas Island Blind Snake, Abbott's Booby, and Sadleir's Bow-fingered Gecko. The KBA is triggered under multiple criteria: A1a, A1b, A1e, B1, B2, D1a, D3.
Additional biodiversity: This nomination includes only a small subset of the endemic species to the island. There are estimated to be at least 253 species that are endemic to Christmas Island (including 17 vascular plants, 27 molluscs, 15 crustaceans, 150 insects and 21 vertebrates) see James et. al. 2019.
The marine waters of Christmas Island supports over 600 fish species, including migratory whale sharks (Rhincodon typus), and other species such as Green Turtles (Chelonia mydas) and Hawksbill Turtles (Eretmochelys imbricata). A comprehensive assessment of marine biodiversity triggers is recommended.
In addition to the listed trigger species, the island is home to endemic subspecies including: the Christmas Island Goshawk, the Christmas Island Emerald Dove, and the Christmas Island Thrush, which are all listed as threatened (Endangered or Critically Endangered) nationally; and the Golden Bosun (White-tailed Tropicbird), Indian Ocean Red-tailed Tropicbird, and Christmas Island Flying Fox (Blyth's Flying Fox).
Two endemic species of reptile are extinct in the wild extinct, but persist in captive breeding programs: the Christmas Island Blue-tailed Shinning-skink (Cryptoblepharus egeriae), and the Christmas Island Chained Gecko (Lepidodactylus listeri). If they were successfully reintroduced they would qualify as triggers under A1e.
Manageability of the site: The KBA is readily manageable as a single unit because most area falls within Christmas Island National Park, managed by Parks Australia under the Department of Climate Change, Energy, the Environment and Water. Remaining Crown land on the island is managed by the Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts (DITRDCSA). Parks Australia conducts monitoring, invasive species control, and research both within and outside the National Park, in consultation with DITRDCSA and the Shire of Christmas Island as appropriate. The island is ecologically cohesive, with no natural barriers to species movement. Endemic fauna, including the Christmas Island Flying-fox and red crabs, occur and utilise habitat across the island for foraging, roosting, and migration. Consequently, the entire island forms a logical and practical single management unit for maintaining the integrity of biodiversity values.
Delineation rationale: The KBA boundary encompasses the entire landmass of Christmas Island and extends 50 m offshore. It was delineated using two datasets: the Collaborative Australian Protected Area Database (CAPAD) 2022 – Terrestrial, for the Christmas Island National Park boundary, and the Australian Bureau of Statistics States and Territories (STE) 2021 dataset, for the island’s shoreline. The CAPAD Nationl Park boundary (which already extends 50 m offshore) was used for the portion of the island covered by the National Park. For areas outside the National Park, a 50 m buffer was applied to the STE shoreline. Although both datasets were intended to represent a consistent 50m buffered coastline, they do not align perfectly. Where the two boundaries meet, a simple smoothing approach was applied — the corner was cut with a straight line at approximately 45 degrees.
Habitats
Summary of habitats in KBA: The vegetation is predominantly a floristically depauperate but structurally complex rainforest at the interior of the island, with semi-deciduous vine thickets on coastal terraces. Approximately 25% of the island has been cleared of native vegetation and comprises open rocky ground, weed fields, secondary growth and urban areas (Stokes 1988; Flora of Australia 1993; Director of National Parks 2000; Johnstone and Darnell 2004).
Threats
Summary of threats to biodiversity at KBA: Non-native plants and animals introduced historically or via ongoing vectors (air/sea freight, inter-island movements) are a significant threat and have contributed to species decline and extinction. Yellow crazy ants, feral cats, Asian wolf snakes, giant centipedes, scale insects and transformer weeds are the headline risks. Historic clearing for development and phosphate mining, and continuing clearing of regrowth forest creates fragmentation and edge effects. Climate change and the increasing risk of ocean warming/acidification (causing impacts to coral reef), rainfall and monsoon timing shifts, heatwaves and cyclonic winds threatens species and ecosystems.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Pollution | Air-borne pollutants | Smog | Ongoing |
| Energy production & mining | Mining & quarrying | Ongoing | |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Named species | Ongoing |
| Invasive & other problematic species, genes & diseases | Invasive non-native/alien species/diseases | Unspecified species | Ongoing |
| Residential & commercial development | Housing & urban areas | Ongoing | |
| Climate change & severe weather | Other impacts | Ongoing |
Additional information
Contributors: John Woinarski (Charles Darwin University), Michael Pennay (Australasian Bat Society), Yuna Kim (BirdLife Australia), Alexia Jankowski (Parks Australia), Stephanie Todd (BirdLife Australia), Anna McCallum (BirdLife Australia), Dave Waldien (IUCN), Andrew Snyder (Re:Wild), Nicholas MacGregor (Parks Australia), Christina Lipka (Parks Australia)