Christmas Island Swiftlet
Encyclopedia
The Christmas Island Swiftlet (Collocalia esculenta natalis), also known as the Christmas Island Glossy Swiftlet or the Christmas Island Cave Swiftlet, is a small bird
in the swift
family
Apodidae. It is endemic to Christmas Island
, an Australia
n territory in the eastern Indian Ocean
.
. It has usually been considered a subspecies
of the Glossy Swiftlet
(Collocalia esculenta). However, Christidis and Boles (2008) treat it as a subspecies of the Cave Swiftlet (Collocalia linchi). Here it is kept as a subspecies of the Glossy Swiftlet pending further study of its genome.
that covers 75% of the island, as well as over other terrestrial habitats there. It nests mainly in caves in the limestone
cliffs surrounding the island.
. The nests are made of dried palm fibres and lichen and are cemented to the cave wall with the bird’s saliva.
s which were accidentally introduced to the island. The threat is not only that of direct ant predation of swiftlet nestlings, but also indirectly from potentially massive changes to the ecology of the island caused by the ants. However, the swiftlet is not listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999
.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the swift
Swift
The swifts are a family, Apodidae, of highly aerial birds. They are superficially similar to swallows, but are actually not closely related to passerine species at all; swifts are in the separate order Apodiformes, which they share with hummingbirds...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Apodidae. It is endemic to 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 eastern 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...
.
Taxonomy
The taxon was described in 1889 by ListerJoseph Jackson Lister (naturalist)
Joseph Jackson Lister FRS was a British zoologist and plant collector from Leytonstone who collected biological specimens during travels in Africa, Asia, Australasia and the Pacific region....
. It has usually been considered a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Glossy Swiftlet
Glossy Swiftlet
The Glossy Swiftlet is a species of swift in the Apodidae family.It is found in Australia, Brunei, Christmas Island, India, Indonesia, Malaysia, Myanmar, New Caledonia, Papua New Guinea, the Philippines, Singapore, Solomon Islands, Thailand, and Vanuatu.It is shiny black-blue above, including its...
(Collocalia esculenta). However, Christidis and Boles (2008) treat it as a subspecies of the Cave Swiftlet (Collocalia linchi). Here it is kept as a subspecies of the Glossy Swiftlet pending further study of its genome.
Description
The Christmas Island Swiftlet is a small swiftlet some 9-11 cm in length. It is mainly glossy blue-black or green-black above, with dark grey underparts relieved by a prominent white belly and vent.Distribution and habitat
The swiftlet is restricted to the 135 km2 Christmas Island where it is commonly seen in large numbers in flight above the tropical rainforestRainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
that covers 75% of the island, as well as over other terrestrial habitats there. It nests mainly in caves in the limestone
Limestone
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....
cliffs surrounding the island.
Breeding
The swiftlet breeds deep in caves, in almost total darkness. It builds a small cup-shaped nest for its clutch of two eggs, high up on the cave wall and often sheltered by a stalactiteStalactite
A stalactite , "to drip", and meaning "that which drips") is a type of speleothem that hangs from the ceiling of limestone caves. It is a type of dripstone...
. The nests are made of dried palm fibres and lichen and are cemented to the cave wall with the bird’s saliva.
Status and conservation
Garnett & Crowley (2000) considered the swiftlet, along with a suite of Christmas Island’s other endemics, as critically endangered, with the principal threat coming from the yellow crazy antYellow 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....
s which were accidentally introduced to the island. The threat is not only that of direct ant predation of swiftlet nestlings, but also indirectly from potentially massive changes to the ecology of the island caused by the ants. However, the swiftlet is not listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999
Environment 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...
.