Christmas Island National Park
Encyclopedia
Christmas Island National Park is a national park
occupying most of Christmas Island
, an Australia
n territory in the Indian Ocean
southwest of Indonesia
. 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 Abbott's Booby
and critically endangered
Christmas Island Frigatebird
, and the wide range of other endemic species makes the island of significant interest to the scientific community.
mining on the flora and fauna of Christmas Island. A particular focus was on the habitat of Abbott's Booby
(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 85 km² (32.8 sq mi), or 63% of the island.
cap metamorphosed
from coral reef
s overlying more ancient volcanic andesite
bedrock. The underlying seamount
lies some 500 km (310.7 mi) southwest of Indonesia, and the isolation by the abyssal zone
has led to endemism amongst the marine ecosystem. The park's boundaries extend 50 m (164 ft) beyond the low water line. Approximately 46 kilometres (28.6 mi) of the island's 73 kilometres (45.4 mi) 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 pools. Sea cliffs, up to 60 metres (196.9 ft) 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 underground cave
system. There are both water-filled and dry caves.
Christmas Island's two Ramsar sites
, The Dales and Hosnies Spring
, are contained within the park.
Both the waters surrounding the island and its land surface are fecund, and the park exhibits a high level of biodiversity
with many endemic species.
s (Gecarcoidea natalis), whose mass migrations at spawning time may number over a hundred million individuals. The bright red carapace
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
yellow crazy ant
(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
(Birgus latro), the world's largest land invertebrate
. There may be as many as one million coconut crabs on Christmas Island. It is also home to several species each of hermit crab
, grapsids
and gecarcinucoidea
.
(Lepidodactylus listeri), the forest skink (Emoia nativitatis), the blue-tailed skink (Cryptoblephanus egeriae) and the pink blind snake
(Ramphotyphlops exocoeti). The foreshore skink (Emoia atrocostata) is native to the park, but is also to be found on other islands of the Indian Ocean
. 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 (Hemidactylus frenatus), house gecko
(Gehyra mutilata), black blind snake
(Ramphotyphlops braminus), wolf snake
(Lycodon aulicus capucinus) and grass skink
(Lygosoma bowringii).
(Crocidura trichura), listed as Critically Endangered, and possibly extinct; the small Christmas Island Pipistrelle
(Pipistrellus murrayi), listed as Endangered and showing a rapid decrease in numbers; and the Christmas Island Flying Fox (Pteropus melanotus). The black rat
(Rattus rattus) and house mouse
(Mus musculus) have been introduced. Feral cats and dogs are also common, and stray into park territory.
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There are over 100 species of birds, of which ten are endemic. Many birds are passing vagrant
s, such as the Great Cormorant
(Phalacrocorax carbo). Others, like the Lesser Frigatebird
(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.
. Approximately 200 species of native flowering plant
are to be found on Christmas Island. There are no mangrove
s on the park's coast. However, a stand of the normally estuarine mangrove species, Bruguiera gymnorhiza and B. sexangula, is found approximately 50 metres (164 ft) above sea level, at Hosnies Spring
.
. Its 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 on the northern side of the island.
National park
A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently A national park is a reserve of natural, semi-natural, or developed land that a sovereign state declares or...
occupying most of Christmas Island
Christmas Island
The Territory of Christmas Island is a territory of Australia in the Indian Ocean. It is located northwest of the Western Australian city of Perth, south of the Indonesian capital, Jakarta, and ENE of the Cocos Islands....
, an Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n territory in the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
southwest of Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. The park is home to many species of animal and plant life, including the eponymous red crab
Christmas Island red crab
The Christmas Island red crab, Gecarcoidea natalis, is a species of land crab that is endemic to Christmas Island and the Cocos Islands in the Indian Ocean...
, whose annual migration sees around 100 million crabs move to the sea to spawn. Christmas Island is the only nesting place for the endangered Abbott's Booby
Abbott's Booby
Abbott’s Booby is a large endangered seabird of the gannet family, Sulidae. Found normally only on and around Christmas Island Abbott’s Booby (Papasula abbotti) is a large endangered seabird of the gannet family, Sulidae. Found normally only on and around Christmas Island Abbott’s Booby (Papasula...
and critically endangered
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
Christmas Island Frigatebird
Christmas Island Frigatebird
The Christmas Frigatebird or Christmas Island Frigatebird is a frigatebird endemic to the Christmas Islands in the Indian Ocean...
, and the wide range of other endemic species makes the island of significant interest to the scientific community.
History
Concerns were expressed in the early 1970s about the effect of phosphatePhosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
mining on the flora and fauna of Christmas Island. A particular focus was on the habitat of Abbott's Booby
Abbott's Booby
Abbott’s Booby is a large endangered seabird of the gannet family, Sulidae. Found normally only on and around Christmas Island Abbott’s Booby (Papasula abbotti) is a large endangered seabird of the gannet family, Sulidae. Found normally only on and around Christmas Island Abbott’s Booby (Papasula...
(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 85 km² (32.8 sq mi), or 63% of the island.
Geology and geography
Christmas Island consists of an uplifted limestoneLimestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
cap metamorphosed
Metamorphism
Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...
from coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s overlying more ancient volcanic andesite
Andesite
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...
bedrock. The underlying seamount
Seamount
A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface , and thus is not an island. These are typically formed from extinct volcanoes, that rise abruptly and are usually found rising from a seafloor of depth. They are defined by oceanographers as...
lies some 500 km (310.7 mi) southwest of Indonesia, and the isolation by the abyssal zone
Abyssal zone
The abyssal zone is the abyssopelagic layer or pelagic zone that contains the very deep benthic communities near the bottom of oceans. "Abyss" derives from the Greek word ἄβυσσος, meaning bottomless. At depths of 4,000 to 6,000 metres , this zone remains in perpetual darkness and never receives...
has led to endemism amongst the marine ecosystem. The park's boundaries extend 50 m (164 ft) beyond the low water line. Approximately 46 kilometres (28.6 mi) of the island's 73 kilometres (45.4 mi) 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 pools. Sea cliffs, up to 60 metres (196.9 ft) 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 underground cave
Cave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
system. There are both water-filled and dry caves.
Christmas Island's two Ramsar sites
Ramsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...
, The Dales and Hosnies Spring
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 being of international importance by designation under the Ramsar Convention on Wetlands.-History:Hosnies Spring was...
, are contained within the park.
Flora & Fauna
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...
with many endemic species.
Crabs
The island is particularly noted for its prodigious populations of Christmas Island red crabChristmas Island red crab
The Christmas Island red crab, Gecarcoidea natalis, is a species of land crab that is endemic to Christmas Island and the Cocos Islands in the Indian Ocean...
s (Gecarcoidea natalis), whose mass migrations at spawning time may number over a hundred million individuals. The bright red carapace
Carapace
A carapace is a dorsal 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 tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
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 species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
yellow crazy ant
Yellow crazy ant
The yellow crazy ant is a species of ant, introduced accidentally to northern Australia and Christmas Island in the Indian Ocean, that has wreaked ecological damage in both locations....
(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
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 land-living arthropod in the world, and is probably at the upper size limit of terrestrial animals with exoskeletons in today's atmosphere at a weight of up to...
(Birgus latro), the world's largest land invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
. 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 crab
Hermit crabs are decapod crustaceans of the superfamily Paguroidea. Most of the 1100 species possess an asymmetrical abdomen which is concealed in an empty gastropod shell that is carried around by the hermit crab.-Description:...
, grapsids
Grapsidae
Grapsidae is a family of crabs known variously as marsh crabs, shore crabs or talon crabs. It is not confirmed that the family forms a monophyletic group and some taxa may belong in other families...
and gecarcinucoidea
Gecarcinucoidea
Gecarcinucoidea is a superfamily of freshwater crabs. Its members have been grouped into families in various ways, with some authors recognising families such as "Deckeniidae", "Sundathelphusidae", but only two families are currently recognised: Gecarcinucidae and Parathelphusidae....
.
Reptiles
There are six species of reptile native to the park, of which five are endemic: the giant gecko (Cyrtodactylus sadlieri), the Christmas Island geckoLepidodactylus listeri
Lepidodactylus listeri, commonly known as Lister's Gecko or the Christmas Island Gecko, is a species of gecko endemic to Christmas Island. It is named after naturalist Joseph Jackson Lister.-Description and Habitat :...
(Lepidodactylus listeri), the forest skink (Emoia nativitatis), the blue-tailed skink (Cryptoblephanus egeriae) and the pink blind snake
Ramphotyphlops exocoeti
Ramphotyphlops exocoeti is a blind snake species endemic to Christmas Island. No subspecies are currently recognized.-Geographic range:Found on Christmas Island The type locality given is -Conservation status:...
(Ramphotyphlops exocoeti). The foreshore skink (Emoia atrocostata) is native to the park, but is also to be found on other islands of the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
. 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 (Hemidactylus frenatus), house gecko
Gehyra mutilata
The four-clawed gecko is a wide-ranging lizard that is probably native to Southeast Asia. It has made its way to several areas of the world including Sri Lanka, Indochina, and many of the U.S. Pacific Islands...
(Gehyra mutilata), black blind snake
Ramphotyphlops braminus
Ramphotyphlops braminus is a harmless blind snake species found mostly in Africa and Asia, but has been introduced in many other parts of the world. Completely fossorial, they are often mistaken for earthworms, except that they are not segmented. The specific name is a Latinized form of the word...
(Ramphotyphlops braminus), wolf snake
Lycodon aulicus
The Indian wolf snake is a species of nonvenomous snake found in South Asia and Southeast Asia. Early naturalists have suggested its resemblance to the venomous common krait as an instance of Batesian mimicry.-Description:...
(Lycodon aulicus capucinus) and grass skink
Lygosoma bowringii
Christmas Island Grass-skink or Bowring's Supple Skink Lygosoma bowringii is a species of skink found in Southeast Asia.-Distribution:West Malaysia, Pulau Tioman, Johor: Pulau Besar, Pulau Sibu; India ,...
(Lygosoma bowringii).
Mammals
There are three species of mammal native to the park: the Christmas Island ShrewChristmas Island Shrew
The Christmas Island Shrew , also known as Christmas Island Musk-shrew is an extremely rare or possibly extinct shrew from Christmas Island...
(Crocidura trichura), listed as Critically Endangered, and possibly extinct; the small Christmas Island Pipistrelle
Christmas Island Pipistrelle
The Christmas Island Pipistrelle is a species of vesper bat found only on Christmas Island, Australia.It is a small bat weighing around 3 to 4.5 grams. It has sometimes been considered synonymous with Pipistrellus tenuis; however, revisions of the genus based on baculum have identified...
(Pipistrellus murrayi), listed as Endangered and showing a rapid decrease in numbers; and the Christmas Island Flying Fox (Pteropus melanotus). The black rat
Black Rat
The black rat is a common long-tailed rodent of the genus Rattus in the subfamily Murinae . The species originated in tropical Asia and spread through the Near East in Roman times before reaching Europe by the 1st century and spreading with Europeans across the world.-Taxonomy:The black rat was...
(Rattus rattus) and house mouse
House mouse
The house mouse is a small rodent, a mouse, one of the most numerous species of the genus Mus.As a wild animal the house mouse mainly lives associated with humans, causing damage to crops and stored food....
(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 (biology)
Vagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used...
s, such as the Great Cormorant
Great Cormorant
The Great Cormorant , known as the Great Black Cormorant across the Northern Hemisphere, the Black Cormorant in Australia and the Black Shag further south in New Zealand, is a widespread member of the cormorant family of seabirds...
(Phalacrocorax carbo). Others, like the Lesser Frigatebird
Lesser Frigatebird
The Lesser Frigatebird, Fregata ariel, is a species of frigatebird.It nests in Australia, among other locations.There is a single record from the Western Palearctic, from Eilat in the Gulf of Aqaba....
(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 rainforestRainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
. Approximately 200 species of native flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
are to be found on Christmas Island. There are no mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s on the park's coast. However, a stand of the normally estuarine mangrove species, Bruguiera gymnorhiza and B. sexangula, is found approximately 50 metres (164 ft) above sea level, at Hosnies Spring
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 being of international importance by designation under the Ramsar Convention on Wetlands.-History:Hosnies Spring was...
.
Park management
The park is managed by Parks Australia, a division of the Department of the Environment, Water, Heritage and the Arts. Parks Australia's activities are mandated by the Environment Protection and Biodiversity Conservation Act 1999Environment Protection and Biodiversity Conservation Act 1999
The Environment Protection and Biodiversity Conservation Act 1999 is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and culturally significant places...
. Its 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 on the northern side of the island.