{{Taxobox
| name = Christmas Island pipistrelle
| status = CR 
|status_system = iucn3.1
| regnum = Animalia
| classis = Mammalia
| ordo = Chiroptera
| familia = Vespertilionidae
| genus = Pipistrellus
| binomial = Pipistrellus murrayi
| binomial_authority = (Andrews, 1900)
| synonyms = Pipistrellus tenuis murrayi Koopman 1973, 1993}}

The Christmas Island pipistrelle (Pipistrellus murrayi) was a species of bat in the Vespertilionidae family. Biologists believe the bat became extinct on 27 August 2009.

It was a small bat (it weighed ), and lived only on Christmas Island, Australia.van Dyck S. & Strahan R. (eds) 2008. The mammals of Australia. It was thought to be the same as the Pipistrellus tenuis,Koopman K.F. 1993. Order Chiroptera. 137-241 in: Wilson D.E. & Reeder D.M. (eds) Mammal species of the world: a taxonomic and geographic reference. Smithsonian Institution Press, Washington D.C. but research on the bat's baculum (a penis bone) showed that Pipistrellus murrayi'' was a different species.

Decline  
The numbers of Christmas Island Pipistrelle bats had dropped a lot in the last 20 years. It had once been seen all over the island, including in the Settlement. It went from at least 80% of its living range, and its numbers had dropped more than 90% since 1994. Research into the number of bats in January 2009, shows there were only about 20 bats left. The only known group resting place had only four bats. The last bat call was heard on 26 August 2009.

Cause of decline 
Scientists do not know why the Christmas Island Pipistrelle's numbers dropped. Several possible threats may have been:
being eaten
disturbed at their resting spots
an unknown disease.

A number of animals brought to Christmas Island could be the problem:
Common Wolf Snake
 Giant Centipede 
Yellow Crazy Ant
Black Rat
Cats

Saving the pipistrelle
Early in 2009, the Australian Minister for the Environment, Peter Garrett, stopped scientists from trying to set up a captive breeding program. He said that the bats were too hard to catch, and no one knew how to keep them alive in cages. Instead, he announced a program to breed a similar bat in the Northern Territory of Australia. Scientists would learn about caring and breeding bats, then use this information to save the Christmas Island Pipistrelle. Other scientists had said this would take too long, and the bats would become extinct. Scientists believed that by June 2009 there were only four of the bats left in the world. In July 2009, the Australian Government changed its earlier decision and said that it would try to capture the last of the bats and use them to try and breed more bats in captivity. During August and September 2009 scientists searched for the remaining bats to catch them and protect them.  At the end of August only one bat had been heard. Scientists tried to catch this bat, but it has not been heard from since the night of 26 August. It is now believed that the bat is extinct. This may be one of the few times that the extinction of a species in the wild can be known to the exact day.  Scientists will continue to search for the bat, but there has been no signs of the bat since.

References 

Mammals of Australia
Bats
Christmas Island