National Recovery Plan for the Christmas Island Shrew (Crocidura attenuata trichura)

Introduction

The Christmas Island Shrew Crocidura attenuata trichura is the only member of the shrew family (Soricidae) recorded in Australia. The genus of white-toothed shrews Crocidura, with 158 recognised species, is the most speciose of all mammalian genera (Wolsan & Hutterer 1998, Nowak 1999). The taxonomy and distribution of many members of the genera is confusing and inconclusive (Nowak 1999, Jiang & Hoffmann 2001). All members of the genus are small, with a head and body length of 40-180mm and tail length of 40-110mm and a distinctly pointed muzzle.

The Christmas Island Shrew varies from light or reddish-brown to dark slate grey in colouration, with a weight range between 4.5 and 6.0g (Meek 2000; J. Tranter, Dept Environment and Heritage, pers. comm.). It is similar in appearance and occupies a corresponding niche to small Australian carnivorous marsupials (Dasyuridae), such as planigales Planigale sp. and dunnarts Sminthopsis sp. (Eisenberg 1981).

This little animal was once extremely common all over the island and its distinctive shrill squeaks could be heard all around as one stood quietly in the rainforest (Lister 1888, Andrews 1900). By 1908 it was considered to be probably extinct with no specimen either seen or heard during a visit by Andrews (1909). It was rediscovered in 1985, with two specimens located accidentally over a period of less than one month in rainforest on the western side of the island (Meek 2000; J. Tranter, DEH, pers. comm.). Following inquiries by Meek (1998), it was reported that two specimens were encountered in 1958 during rainforest clearing operations for phosphate mining near South Point. However, since 1985, no further individuals have been recorded despite various targeted surveys across the island using a variety of techniques (e.g. Meek 2000), fauna surveys as a component of environmental assessment reports for development proposals, and during the course of field studies on other rainforest fauna. Given there are only two confirmed records over the past century, the Christmas Island shrew has to be considered as extremely rare or possibly extinct.

The most important short-term objective of the Recovery Plan is to initiate targeted field surveys to determine the current distribution and status of the Christmas Island Shrew.