Christmas Island is located in the Indian Ocean, close to the Indonesian archipelago. Since the Island was first colonised in the late 19th century it has suffered great losses amongst its endemic fauna. Only one of the original five native mammals is known to survive on the island presently.
The Christmas Island Shrew was the third of the five native mammals to have become extinct on the island since humans settled there. However, anecdotal evidence suggests shrews may still occur in exceptionally low numbers on Christmas Island.
It has taken a recent detailed study of the mitochondrial DNA (DNA passed on from the female parent) of the two specimens in the Western Australian Museum, together with a few other museum specimens, to clearly establish that the Christmas Island Shrew is quite distinct from its relatives in Indonesia. This identifies it as the only shrew that occurred on Australian territory.
These two individuals in the Western Australian Museum collection represent the last known individuals of the species.