Christmas Island National Park is a

national park A national park is a nature park, natural park in use for conservation (ethic), conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state dec ...

occupying most of

Christmas Island Christmas Island, officially the Territory of Christmas Island, is an Australian external territory comprising the island of the same name. It is located in the Indian Ocean, around south of Java and Sumatra and around north-west of the ...

, an

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

n territory in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

southwest of

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. The park is home to many species of animal and plant life, including the eponymous red crab, whose annual migration sees around 100 million crabs move to the sea to spawn. Christmas Island is the only nesting place for the

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

Abbott's booby Abbott's booby (''Papasula abbotti'') is an endangered seabird of the sulid family, which includes gannets and boobies. It is a large booby and is placed within its own monotypic genus. It was first identified from a specimen collected by Willi ...

and critically endangered

Christmas Island frigatebird The Christmas frigatebird (''Fregata andrewsi''), or Christmas Island frigatebird, is a seabird of the frigatebird family Fregatidae which is an endemic breeder to Christmas Island in the Indian Ocean. The Christmas frigatebird is a large lightl ...

, and the wide range of other

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

species makes the island of significant interest to the scientific community.

History

Concerns were expressed in the early 1970s about the effect of

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...

mining on the flora and fauna of Christmas Island. A particular focus was on the habitat of

(''Papasula abbotti''), which appeared in danger of extinction. In 1974 a governmental committee examined the environmental impact of mining and other commercial activities and advised on measures to protect the island. The committee's recommendation that an area of the island be set aside for conservation was implemented in a series of measures culminating in the establishment of the Christmas Island National Park on 21 February 1980 under the terms of the ''National Parks and Wildlife Conservation Act 1975''. The park initially covered the south-west corner of the island, and was extended in 1986 and 1989 to include most of the rainforest on the island. Today the park covers approximately , or 63% of the island.

Geology and geography

Christmas Island consists of an uplifted

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

cap

metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

from

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

s overlying more ancient volcanic

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomi ...

bedrock. The underlying

seamount A seamount is a large geologic landform that rises from the ocean floor that does not reach to the water's surface (sea level), and thus is not an island, islet or cliff-rock. Seamounts are typically formed from extinct volcanoes that rise abru ...

lies some southwest of Indonesia, and the isolation by the

abyssal zone The abyssal zone or abyssopelagic zone is a layer of the pelagic zone of the ocean. "Abyss" derives from the Greek word , meaning bottomless. At depths of , this zone remains in perpetual darkness. It covers 83% of the total area of the ocean a ...

has led to

endemism Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

amongst the marine ecosystem. The park's boundaries extend beyond the low water line. Approximately of the island's shoreline is within the park limits. Many stretches of the shoreline are marked by rock platforms, which are filled by wave splashes to create

rock pool A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. Many of these pools exist as separate bodies of water only at low tide. Many tide pool habitats are home to especially adaptable animals that ...

s. Sea cliffs, up to high in places, rise steeply from the sea and form a series of stepped terraces, the lower cliffs of which are higher and steeper. Soil on the island is generally poor, punctuated by limestone pinnacles, and tends to dehydrate during the dry season. The limestone is fractured and has created a substantial

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

system. There are both water-filled and dry caves. Christmas Island's two

Ramsar sites A Ramsar site is a wetland site designated to be of international importance under the Ramsar Convention,8 ha (O) *** Permanent 8 ha (P) *** Seasonal Intermittent < 8 ha(Ts) **

The Dales and

Hosnies Spring Hosnies Spring formerly Hosnie's Spring or Hosnies Springs) is a wetland on Christmas Island, an Australian external territory in the eastern Indian Ocean. It has been recognised as being of international importance by designation under the Rams ...

, are contained within the park.

Flora and fauna

Both the waters surrounding the island and its land surface are fecund, and the park exhibits a high level of

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

with many

endemic species Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Fauna

Crabs

The island is particularly noted for its prodigious populations of

Christmas Island red crab The Christmas Island red crab (''Gecarcoidea natalis'') is a species of land crab that is endemic to Christmas Island and Cocos (Keeling) Islands in the Indian Ocean. Although restricted to a relatively small area, an estimated 43.7 million adu ...

s (''Gecarcoidea natalis''), whose mass migrations at spawning time may number over a hundred million individuals. The bright red

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

s and sheer density of crabs make their routes to the sea observable from the air. Nonetheless, the populations of red crabs are threatened by the arrival of the

invasive Invasive may refer to: *Invasive (medical) procedure *Invasive species *Invasive observation, especially in reference to surveillance *Invasively progressive spread of disease from one organ in the body to another, especially in reference to cancer ...

yellow crazy ant The yellow crazy ant (''Anoplolepis gracilipes''), also known as the long-legged ant or Maldive ant, is a species of ant, thought to be native to West Africa or Asia. They have been accidentally introduced to numerous places in the world's trop ...

(''Anoplolepis gracilipes''). The ant was accidentally introduced between 1915 and 1934, and without any native ant species to compete against, rapidly formed 'supercolonies' of extremely high density. Populations of the ant have been observed bringing down red crabs over a hundred times their combined biomass. ''A. gracilipes'' is thought responsible for killing up to 30 million of the park's crabs. While the red crab is Christmas Island's most numerous crab, the island also hosts the world's largest population of

coconut crab The coconut crab (''Birgus latro'') is a species of terrestrial hermit crab, also known as the robber crab or palm thief. It is the largest terrestrial arthropod in the world, with a weight of up to . It can grow to up to in width from the tip ...

(''Birgus latro''), the world's largest land

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

. There may be as many as one million coconut crabs on Christmas Island. It is also home to several species each of

hermit crab Hermit crabs are anomuran decapod crustaceans of the superfamily Paguroidea that have adapted to occupy empty scavenged mollusc shells to protect their fragile exoskeletons. There are over 800 species of hermit crab, most of which possess an a ...

, grapsids and

gecarcinucoidea Gecarcinucoidea is a superfamily of freshwater crabs. Its members have been grouped into families in various ways, with some authors recognizing families such as "Deckeniidae", "Sundathelphusidae", and "Parathelphusidae", but now only the family ...

Reptiles

There are six species of reptile native to the park, of which five are endemic: the giant gecko (''Cyrtodactylus sadlieri''), the

Christmas Island gecko ''Lepidodactylus listeri'', also known commonly as Lister's gecko or the Christmas Island chained gecko, is a species of gecko, a lizard in the family Gekkonidae, endemic to Christmas Island in the Indian Ocean. It is currently extinct in t ...

(''Lepidodactylus listeri''), the forest skink (''Emoia nativitatis''), the blue-tailed skink (''Cryptoblephanus egeriae'') and the

Christmas Island blind snake The Christmas Island blind snake (''Ramphotyphlops exocoeti)'' is a species of snake in the family Typhlopidae. The species is endemic to Christmas Island. There are no subspecies that are recognized as being valid. Etymology The specific na ...

(''Ramphotyphlops exocoeti''). The foreshore skink (''Emoia atrocostata'') is native to the park, but is also to be found on other islands of the

. All have been showing decline in recent years. A further five species of reptile have been reported, but all were introduced by human activity: the

barking gecko ''Ptenopus'' is a small genus of lizards, known commonly as barking geckos, in the family Gekkonidae. The genus is endemic to southern Africa. There are only three described species in this genus. Species and subspecies The following species a ...

(''Hemidactylus frenatus''),

house gecko __NOTOC__ ''Hemidactylus'' is a genus of the common gecko family, Gekkonidae. It has 189 described species, newfound ones being described every few years. These geckos are found in all the tropical regions of the world, extending into the subtrop ...

(''Gehyra mutilata''), black blind snake (''Ramphotyphlops braminus''),

wolf snake ''Lycodon capucinus'', also known as the Oriental wolf snake, is a species of colubrid snake, which is commonly found in the Indo-Australian Archipelago. Named after their enlarged front teeth, which gives them a muzzled appearance similar to can ...

(''Lycodon aulicus capucinus'') and grass skink (''Subdoluseps bowringii'').

Mammals

There are three species of mammal native to the park: the

Christmas Island shrew The Christmas Island shrew (''Crocidura trichura''), also known as the Christmas Island musk-shrew is an extremely rare or possibly extinct shrew from Christmas Island. It was variously placed as subspecies of the Asian gray shrew (''Crocidura at ...

(''Crocidura trichura''), listed as critically endangered, and possibly extinct; the small

Christmas Island pipistrelle The Christmas Island pipistrelle (''Pipistrellus murrayi'') was a species of vesper bat found only on Christmas Island, Australia. The species is now extinct, with the last individual bat seen in August 2009 with no further sightings despite in ...

(''Pipistrellus murrayi''), listed as endangered and showing a rapid decrease in numbers; and the Christmas Island flying fox (''Pteropus melanotus''). The

black rat The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is n ...

(''Rattus rattus'') and

house mouse The house mouse (''Mus musculus'') is a small mammal of the order Rodentia, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus '' Mus''. Althoug ...

(''Mus musculus'') have been introduced. Feral cats and dogs are also common, and stray into park territory.

Birds

There are over 100 species of birds, of which ten are endemic. Many birds are passing

vagrant Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, temporar ...

s, such as the

great cormorant The great cormorant (''Phalacrocorax carbo''), known as the black shag in New Zealand and formerly also known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, and the large cormorant in India, is a w ...

(''Phalacrocorax carbo''). Others, like the

lesser frigatebird The lesser frigatebird (''Fregata ariel'') is a seabird of the frigatebird family Fregatidae. At around 75 cm (30 in) in length, it is the smallest species of frigatebird. It occurs over tropical and subtropical waters across the Indian ...

(''Fregata ariel''), are more regular visitors. Bird populations are threatened due to the invasive yellow crazy ant, and reports have suggested that the ant has attacked hatchlings and harassed adults in their nests. All endemic bird species have been placed on the critically endangered list.

Flora

The dominant vegetation on the island is

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

. Approximately 200 species of native

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

are to be found on Christmas Island. There are no

mangrove A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...

s on the park's coast. However, a stand of the normally

estuarine An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

mangrove species, ''Bruguiera gymnorhiza'' and ''B. sexangula'', is found approximately above sea level, at

Park management

The park is managed by the

Director of National Parks Director of National Parks is a government-owned corporation of the Government of Australia, Australian government responsible for the management of a portfolio of protected area, terrestrial and marine protected areas proclaimed under the ''Env ...

whose duties include protection of the park's natural areas, its lifeforms and genetic resources, to maintain ecological diversity, and to manage visitor access for educational, cultural and recreational purposes. It latest management plan (2002) listed control of the yellow crazy ant as its highest priority. The park administration has a staff of 17, and operates out of an office in

Drumsite Drumsite is a settlement on Christmas Island, Australia. Is located on the northeast coast, near the capital, Flying Fish Cove. The ethnic composition of the population is Chinese and European. In the area there are migration routes of red crabs ...

on the northern side of the island.

References

{{authority control National parks managed by the Australian government Protected areas established in 1980 Geography of Christmas Island 1980 establishments in Australia