HabitatHabitat

Habitat

At the time of settlement, the Christmas Island Shrew was widespread in rainforest extending from the shoreline to the plateau (Lister 1888, Andrews 1900). It was not recorded whether the shrew occurred within other forest communities, for example scrubby forest in exposed situations on shallow soils, coastal fringe vegetation dominated by pandanus Pandanus christmatensis and the Cabbage Tree Scaevola taccada, and in perennially wet areas. The importance to the species of karst terrain (including caves, overhangs, rock crevices, sinkholes, and inland cliffs rising out of the terrace rainforest) is unknown.

The most recent records were of single individuals from tall plateau rainforest in deep soils (J. Tranter, DEH, pers. comm.) and terrace rainforest with shallow soils (P. Goh, DFAT, pers. comm.). The majority of primary plateau and terrace rainforest, including the locations for the two 1985 sightings, is now protected within the Christmas Island National Park. It is unknown whether the shrew may occur in secondary regrowth. There appear to have been no records from around human habitation on the island.

The Christmas Island Shrew was recorded to shelter in holes in rocks and roots of trees, and foraged predominantly on small beetles (Andrews 1900). Other Crocidura species either dig their own burrows in loose soil or leaf mould frequently under fallen trees and rocks or use those of other animals (Nowak 1999). An important component of habitat occupied by some Crocidura shrews is the presence of a high degree of ground cover with associated deep leaf litter and slightly moister soil (Dickman 1995). These preferences are linked to increased prey availability and predator avoidance, but may also facilitate burrow construction (Dickman 1988, 1995). It is not known whether the Christmas Island Shrew favours these microhabitats within the rainforest.