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
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 ...
. 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
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 ...
.
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.
See also
*
Protected areas managed by the Australian government
Protection is any measure taken to guard a thing against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although th ...
References
{{authority control
National parks managed by the Australian government
Protected areas established in 1980
Geography of Christmas Island
1980 establishments in Australia