Crocidura trichura Dobson 1889
Creators: name: Mittermeier, Russell A.
name: Wilson, Don E.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Soricomorpha
Soricidae
Crocidura
Crocidura trichura

description: 281. Christmas Island White-toothed Shrew <i>Crocidura trichura</i> <b>French:</b> Crocidure de Christmas / <b>German:</b> \Weihnachtsinsel-Weif3zahnspitzmaus / <b>Spanish:</b> Musarana de Isla de Navidad <b>Other common names:</b> Christmas Island Shrew <b>Taxonomy.</b> Crocidura fuliginosa trichura Dobson in Thomas, 1889, Christmas Island, Australia. Initially, O. Thomas in 1889 and C. W. An- drews in 1900 regarded trichura as a variety or subspecies within fuliginosa. Other au- thors treated it as a subspecies of attenuata or synonymized it with attenuata. M. Ruedi in 1995 and R. Hutterer in 2005 raised trichura to species rank, which was later confirmed in genetic studies by M. D. B. Eldridge and others in 2009 Sgr and Results of these studies also indicate relationship to lawuana. Monotypic. <b>Distribution.</b> Christmas I (Australia). <b>Descriptive notes.</b> Head—body 65-82 mm, tail 63-80 mm, ear 7-11 mm, hindfoot 13— 17 mm; weight 4-5-6 g. Dense fur of the Christmas Island White-toothed Shrew varies from light or reddish brown to dark slate-gray. Snoutis clearly pointed. Hindfoot and tail, which can reach 88-114% of head-body length, are relatively long compared with the Asian Gray White-toothed Shrew (C. attenuata) and the Southeast Asian Whitetoothed Shrew (C. fuliginosa). Tail is very hairy, covered with fine long hairs and many long bristle hairs. The Christmas Island White-toothed Shrew resembles the Asian Gray White-toothed Shrew in cranial and jaw features. Its skull is relatively narrow in anterior part (widths across maxillae at level of second molar 5-3-5-7 mm) but then wider in posterior part (post-glenoid breadths 6-1-6-5 mm). Greatest skull lengths are 19-1-20-9 mm. <b>Habitat.</b> Rainforests, using rock holes and tree roots as shelter. Records of the Christmas Island White-toothed Shrew are from high plateau forest with deep soils and terrace rainforest with flat soils. Records around human settlements are unknown, and it is not clear if it can adapt to secondary forests or other anthropogenic structures. <b>Food and Feeding.</b> The Christmas Island White-toothed Shrew seems to mainly eat small beetles. <b>Breeding.</b> Generation length of the Christmas Island White-toothed Shrew is assumed to be two years. <b>Activity patterns.</b> The Christmas Island White-toothed Shrew is diurnal and nocturnal. Andrews in 1900 mentioned calls being made at night, and one individual was found on a walking track in the afternoon during mild weather conditions. <b>Movements, Home range and Social organization.</b> No information. <b>Status and Conservation.</b> Classified as Critically Endangered on The IUCN Red List. In 1900, Andrews noted that the Christmas Island White-toothed Shrew was very common, but by 1909, he noted that it was rare. Since then, only four specimens have been confirmed: two in 1958 and two in 1985. There were some unconfirmed reports between 1996 and 1998. Capture attempts with Longworth traps, hair tubes, and pitfall traps in 1997-1998 were unsuccessful. In 2004, a recovery plan for the Christmas Island White-toothed Shrew was prepared, which included investigations on taxonomy, population status, distribution, development of a program for potential habitats outside Christmas Island National Park; control the spread of introduced yellow crazy ants (Anoplolepis gracilipes); establishment of captive breeding program; maintenance of remaining wild population; and identification of threats. Unfortunately, no specimens have been found in recent surveys. The Christmas Island White-toothed Shrew is extremely rare or possibly extinct. In any case, there has been a sharp decline in population, which began shortly after the start of human settlement on the island. Possible causes could be diseases and introduction of invasive yellow crazy ants. Habitat loss, habitat alteration, and excessive predation by introduced (cats and black rats) and natural predators are also possible. K. B. Wyatt and others in 2008 identified pathogenic trypanosomes introduced by infected Roof Rats (Rattus rattus) as the cause of the collapse of the populations of Maclear’s Christmas Island Rat (Rattus maclear), also an endemic species on Christmas Island. Nevertheless, they consider it unlikely that the Christmas Island White-toothed Shrew has been infected because trypanosomes have a high degree of host specificity. They concluded that predation and competition were more likely reasons for the decline of the Christmas Island White-toothed Shrew. <b>Bibliography.</b> Andrews (1900, 1909), Corbet &amp; Hill (1992), Eldridge, Johnson &amp; Meek (2009), Eldridge, Meek &amp; Johnson (2014), Hutterer (2005b), Jackson &amp; Groves (2015), Jenkins (1976, 1982), Meek (2000), Ruedi (1995), Schulz (2004), Thomas (1889), Woinarski, Burbidge &amp; Harrison (2014), Woinarski, Burbidge &amp; Lumsden (2016), Wyatt et al. (2008).
description: Published as part of <i>Russell A. Mittermeier &amp; Don E. Wilson, 2018, Soricidae, pp. 332-551 in Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona :Lynx Edicions</i> on pages 494-495, DOI: 10.5281/zenodo.6870843