Christmas Island Pipistrelle
Encyclopedia
The Christmas Island Pipistrelle (Pipistrellus murrayi) 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 as a distinct species. This is supported by genetic work conducted for the Australian Government as part of its investigation into the decline of Christmas Island ecology and the pipistrelle in mid 2009; the results of this analysis indicate that the Christmas Island Pipistrelle is closely related to but distinct from other Asian pipistrelles.
Grave fears are held that the species may now be extinct, with the last individual bat seen in August 2009 with no further sightings despite intensive efforts to locate the species.
A reassessment of the number of individuals remaining in January 2009 suggested there may have been as few as 20 individuals left. The only known communal roost contained only four individuals. Three years ago there were 54 individuals in this colony and there were several other known, similar-sized colonies. The long-term monitoring data suggested that, if the current rate of decline continued, this species was likely to become extinct around mid 2009. Monitoring in early 2009 showed that some bats survived in the wild, prompting the Australian government to announce on 1 July 2009, that it would attempt to rescue the bat by bringing the last remaining individuals into captivity, with assistance of volunteer bat researchers from the Australasian Bat Society. On 8 September 2009, the Australian Government announced that attempts to capture the bats had failed. A single Christmas Island Pipistrelle was observed in August 2009; none have been seen since, and it is feared the species is now extinct.
, Giant Centipedehttp://www.ento.csiro.au/aicn/name_s/b_3704.htm, Yellow Crazy Ant
, Black Rat
or feral cat
s have all been identified as potential suspects responsible for the decline either through predation or disturbance of the bats. It has also been speculated that an unidentified health threat, or poisoning from the insecticide Fipronil
used to control Yellow Crazy Ant
'supercolonies' could be responsible for the decline.
Vesper bat
Vesper bats , also known as Evening bats or Common bats, are the largest and best-known family of bats. They belong to the suborder Microchiroptera . There are over three hundred species distributed all over the world, on every continent except Antarctica...
found only on 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....
, 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...
.
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 as a distinct species. This is supported by genetic work conducted for the Australian Government as part of its investigation into the decline of Christmas Island ecology and the pipistrelle in mid 2009; the results of this analysis indicate that the Christmas Island Pipistrelle is closely related to but distinct from other Asian pipistrelles.
Grave fears are held that the species may now be extinct, with the last individual bat seen in August 2009 with no further sightings despite intensive efforts to locate the species.
Decline
The Christmas Island Pipistrelle has declined dramatically in the last two decades. It was once commonly seen throughout the island including in the settlement. It has disappeared from at least 80% of its range and declined more than 90% in abundance since 1994.A reassessment of the number of individuals remaining in January 2009 suggested there may have been as few as 20 individuals left. The only known communal roost contained only four individuals. Three years ago there were 54 individuals in this colony and there were several other known, similar-sized colonies. The long-term monitoring data suggested that, if the current rate of decline continued, this species was likely to become extinct around mid 2009. Monitoring in early 2009 showed that some bats survived in the wild, prompting the Australian government to announce on 1 July 2009, that it would attempt to rescue the bat by bringing the last remaining individuals into captivity, with assistance of volunteer bat researchers from the Australasian Bat Society. On 8 September 2009, the Australian Government announced that attempts to capture the bats had failed. A single Christmas Island Pipistrelle was observed in August 2009; none have been seen since, and it is feared the species is now extinct.
Cause of decline
The cause of the Christmas Island Pipistrelle's decline is unknown. Several potential threats have been suggested: predation or disturbance at roost sites, and disease. Introduced species such as the Common Wolf SnakeLycodon capucinus
Lycodon capucinus also known as the common wolf snake is a species of colubrid snake, which is found in the Indo-Australian Archipelago.-Distribution:...
, Giant Centipedehttp://www.ento.csiro.au/aicn/name_s/b_3704.htm, 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....
, 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...
or feral cat
Feral cat
A feral cat is a descendant of a domesticated cat that has returned to the wild. It is distinguished from a stray cat, which is a pet cat that has been lost or abandoned, while feral cats are born in the wild; the offspring of a stray cat can be considered feral if born in the wild.In many parts of...
s have all been identified as potential suspects responsible for the decline either through predation or disturbance of the bats. It has also been speculated that an unidentified health threat, or poisoning from the insecticide Fipronil
Fipronil
Fipronil is a broad spectrum insecticide that disrupts the insect central nervous system by blocking the passage of chloride ions through the GABA receptor and glutamate-gated chloride channels, components of the central nervous system. This causes hyperexcitation of contaminated insects' nerves...
used to control 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....
'supercolonies' could be responsible for the decline.