MacroscelideaId code: amd241
(Eng) Four-toed or forest elephant-shrew
(Fre) Rat à trompe tétradactyle
This species is the only component of its genus (Wilson & Reeder, 1993) and has been subdivided into up to ten subspecies (Nicoll & Rathbun, 1990).
IUCN threat category
Not listed. The subspecies P. t. sangi, reported only from Taita Hills in Kenya, is considered threatened (Nicoll & Rathbun, 1990) and was classified as Insufficiently Known in the 1994 Red List (Anonymous, 1994).
Little is known on the speciesí ecology, and most of the information available concerns the species in Southern Africa. Almost nothing is known on its ecology in Central and East Africa. A detailed account of the information available on the biology of the species in Southern Africa is found in Mills & Hes (1997) and Skinner & Smithers (1990). Data on its distribution in South Africa and conservation issues are discussed in Mugo et al. (1995); notes on its occurrence in Tongaland (KwaZulu, South Africa) are found in Bruton (1978). A detailed account of the ecology of the species in Southern Africa is given in Mills & Hes (1997) and Skinner & Smithers (1990). General information on its ecology and distribution is found in Kingdon (1997). Status and distribution are discussed in Nicoll & Rathbun (1990), who also give a description of the habitat in which it occurs.
Known extent of occurrence
The four-toed elephant-shrew probably has one of the widest distribution range within its order (Nicoll & Rathbun, 1990), often overlapping with both Elephantulus or Rhynchocyon, ranging from Central (Congo and former Zaire) and East (Kenya and Uganda) Africa, southwards to the east coast of South Africa. As shown in Fig. 12.1.12.a, its range is apparently divided into three separate areas. It is present on the islands of Zanzibar and Mafia. Its geographic range was obtained from the map in Skinner & Smithers (1990) for the mainland range and Wilson & Reeder (1993) for the Tanzanian islands. The result was revised on the basis of information found in other sources (Kingdon, 1997; Nicoll & Rathbun, 1990).
Categorical-discrete (CD) distribution model
This species inhabits woodlands and thickets as well as forests (Nicoll & Rathbun, 1990; Haltenorth & Diller, 1980; Kingdon, 1997; Mills & Hes, 1997).
Based on these environmental preferences, the following scores were assigned (Fig. 12.1.12.b) (Tab. 12.1.12.a):
Tab 12.1.12.a: Cumulative size (km2) of areas pertaining to each environmental suitability class within the Extent of Occurrence.
Tab 12.1.12.b: Area of Occupancy fragmentation indexes.
Probabilistic-continuous (PC) distribution model
The output of the probabilistic-continuous (PC) distribution model is shown in Fig. 12.1.12.c.
No occurrence of the species within the four sample areas.
Comments and conservation issues
The known EO of this species is divided into two main sections: while the larger section along the eastern coast is drawn accurately, the shape of the smaller part in central former Zaire appears to be rougher. The separation between them is also not justified on the basis of the existing availability of suitable areas. The overall suitability of the EO is high (97%) and fragmentation appears low (NP and LPI). The AWMSI shows that the most suitable areas have a very irregular shape and form an intricate mosaic with the other areas. The species is not listed by the IUCN threat category system, and about 11.8% of the total AO is included in existing protected areas. These areas are not distributed evenly throughout the range and local populations and subspecies may not be protected.
Tab 12.1.12.c: Percent of environmental suitability classes within EO (as obtained from the categorical-discrete distribution model) inside and outside the protected areas.
Anonymous (1994). IUCN Red List Categories. IUCN, Gland - Switzerland: As approved by IUCN, 30 Nov 1994.
Bruton M.N. (1978). Recent mammal records from eastern Tongaland in Kwazulu, with notes on Hippopotamus in lake Sibaka. Lammergeyer: 24, 19-27.
Haltenorth T., Diller H. (1980). A field guide to the mammals of Africa, including Madagascar. Collins, London.
Kingdon J. (1997). The Kingdon field guide to African Mammals. Academic Press, London and New York: Natural World.
Mills G., Hes L. (1997). The complete book of Southern African mammals. Struik Publishers.
Mugo D.N., Lombard A.T., Bronner G.N., Gelderblom C.M. (1995). Distribution and protection of endemic or threatened rodents, lagomorphs and macroscelidids in South Africa. In: Anonymous (1995). Vertebrate Conservation in South Africa. Papers presented at the ZSSA symposium, July 1994. S. Afr. J. Zool.: 30(3), 115-126.
Nicoll M.E., Rathbun G.B. (Eds) (1990). African Insectivora and Elephant-Shrews. An Action Plan for their Conservation. IUCN/SSC Insectivore, Tree-Shrew and Elephant Shrew Specialist Group.
Skinner J.D., Smithers R.H.N. (1990). The mammals of the Southern African subregion. University of Pretoria, Pretoria.
Wilson D.E., Reeder D.M. (Eds) (1993). Mammal Species of the World: A Taxonomic and Geographic Reference. Second edition. Smithsonian Institution Press, Washington D.C.