Grey-faced elephant-shrew (Rhynchocyon udzungwensis)

Also known as: grey-faced sengi
KingdomAnimalia
PhylumChordata
ClassMammalia
OrderMacroscelidea
FamilyMacroscelididae
GenusRhynchocyon (1)
SizeAverage length: 56.4 cm (2)
Average weight: 710 g (2)

The grey-faced elephant-shrew is classified as Vulnerable (VU) on the IUCN Red List (1).

It was as recently as 2005 that a camera-trap, placed in mountainous forest in Tanzania, captured images of a species of elephant-shrew (also known as sengis) that had never been photographed before. Spurred by these images, a group of scientists went to investigate, and in 2006 captured a number of individuals that were to become known as grey-faced elephant-shrews (Rhynchocyon udzungwensis) (2). The grey-faced elephant-shrew is over 25 percent larger than any sengi previously described and also differs in the colour of its sparse, glossy and stiff fur. It is, as the name suggests, grey on the face and forehead, turning slightly grizzled yellow-rufous to the shoulders, then orange-rufous on the sides and jet black on the lower rump and thighs. Making this elephant-shrew even more colourful is a wide, indistinct, maroon stripe that extends down the back (2).

Elephant-shrews are named for their long, trunk-like snout, which for the first two centimetres is essentially naked and black (2). Bizarrely, recent molecular evidence has shown that elephant-shrews are more closely related to elephants than true shrews (3). Other body parts of the elephant-shrew resemble other animals: the legs are long, like those of a small antelope, and the long tail is like that of a rat (4). The tail of this species, is black on the upper surface, dark brown underneath, and has a white band, four to six centimetres long, near the tip (2).

Endemic to the Udzungwa Mountains of south-central Tanzania, the grey-faced elephant-shrew occurs in just two forests: the Ndundulu–Luhomero forest and the Mwanihana forest. These forests are separated by about 20 kilometres of grassland and woodland, which is unlikely to be suitable habitat for the grey-faced elephant shrew (2). The Udzungwa Mountains form part of the Eastern Arc Mountains, a series of ancient mountains stretching from southern Kenya to south-central Tanzania (2).

The grey-faced elephant-shrew inhabits moist, closed canopy, mountain forest and bamboo thickets, between 1,000 and 2,300 metres above sea level (2). The canopy of the forests in which this species is found is typically between 10 and 50 metres high, and the forest floor is covered in leaf litter, or has a more dense covering of grasses, herbs and tree seedlings (2).

Although its recent discovery means that little is known about the biology and ecology of the grey-faced elephant-shrew, it is likely to be similar to that of other elephant-shrews. It is known to be a strictly diurnal species (2), and like other elephant-shrews, probably spends the majority of the day searching for invertebrate prey on the forest floor, probing the leaf litter with its long, flexible nose (4). It may also use its clawed forefeet to dig small holes in the soil to unearth food. All sengis have long tongues that can reach beyond the tip of their elongated noses, which are used to flick small prey into their mouths (4).

Nests of the grey-faced elephant-shrew include an oval cup-shaped excavation dug into the soil which is lined with layers of dry leaves. Loose leaves are then piled on top to form a vague dome that blends into the thick leaf litter covering the forest floor. The nests of this species are often located at the base of large trees (2). Like other sengis, the grey-faced elephant-shrew may be socially monogamous, and gives birth to litters of one or two young that are confined to the nest for two to three weeks before emerging (4).

The restricted range of the grey-faced elephant-shrew makes it vulnerable to any threats that may arise. Currently, the most significant threat to this species is the loss of habitat as a result of forest fires, both those induced by drought and those caused intentionally by humans (1). The proximity of this species’ habitat to rapidly expanding human populations means there is an increasing possibility of habitat loss from fires and logging, and an increased risk of poaching (1) (2). In the longer term, global climate change may pose a  threat to the survival of the grey-faced elephant-shrew, as it could significantly alter the moist montane forest it inhabits (1).

The two forests from which the grey-faced elephant-shrew is currently known are both protected areas: the Udzungwa Mountains National Park and the West Kilombero Scarp Forest Reserve (2). The hunting of animals for food or trade within either area is prohibited, and the biodiversity of the Udzungwa Mountains National Park also benefits from a management plan and a community education and outreach plan (1). The grey-faced elephant-shrew is just one of at least 25 new vertebrate species which have been discovered in the Eastern Arc Mountains and Tanzanian southern highlands in the last decade (2), adding to the thousands of endemic species already known from this region (5). This highlights the global importance of conserving these ancient forests (2), to ensure the survival of the numerous animals and plants that are found nowhere else on earth (5).

For further information on conservation in the Eastern Arc Mountains:

 For further information on sengis and other African wildlife:

Authenticated (14/03/11) by Galen Rathburn. Chair, IUCN-SSC Afrotheria Specialist Group.
http://www.afrotheria.net/ASG.html

  1. IUCN Red List (October, 2008)
    http://www.iucnredlist.org
  2. Rovero, F., Rathbun, G.B., Perkin, A., Jones, T., Ribble, D.O., Leonard, C., Mwakisoma, R.R. and Doggart, N. (2008) A new species of giant sengi or elephant-shrew (genus Rhynchocyon) highlights the exceptional biodiversity of the Udzungwa Mountains of Tanzania. Journal of Zoology, 274: 126 - 133.
  3. California Academy of Science. (2008) A discovery of elephantine proportions. California Academy of Sciences Member Publication, 8: 3 - 4.
  4. Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford.
  5. Eastern Arc Mountains Conservation Endowment Fund (October, 2008)
    http://www.easternarc.or.tz