Elephant shrews, a group of about 15 species, small in comparison to other orders of mammals, has always posed a problem for taxonomists. They take their common name from their elephant-like snout and their resemblance to a shrew. Originally they were placed in the order Insectivora in the family Macroscelididae even though the main trait they shared in common with Insectivores is diet. They have been grouped with tree shrews, hares, rabbits, hyraxes and primates in the past. Now it is recognized that this small group constitutes its own order, the Macroscelidea, based on its early split from other mammalian groups and an unusal unique set of features (Grizmeck's 1990).
Perception Channels: tactile ; chemical
There is little known about the threats facing this elephant shrew, unlike the cases of 7 other macroscelidid species ranging from vulnerable to endangered listed by the IUCN as of 2001. However, habitat modification in their areas of the forests of Africa may be a problem in the future. The good news for this particular elephant shrew is that, since its geographic range is greater than some of its relatives, the risks of becoming endangered are not as high at this time. However, in order to preserve the species deforestation must be minimized, directly affecting the local people of the region and their need to make room for more agricultural lands. The future depends on the establishment of protected areas within these integrated rural land developments, which aim to be beneficial to both the biological diversity and the needs of the local people (Nicoll and Rathbun 1990).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Insects being the main portion of the diet of these animals, they are probably important in helping to control pest populations. This may in turn help neighboring farm crops.
Positive Impacts: controls pest population
The long elephant-like snout enables these mammals to find insects within the dense forests of Africa. Termites and ants are preferred. In general, insects make up the largest portion of the diet of this elephant shrew but they eat some plant material as well (Rathbun 1979).
Animal Foods: insects; terrestrial non-insect arthropods
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: carnivore (Insectivore )
The 15 species of Elephant shrews are restricted to Africa (Nicoll and Rathbun 1990). The four toed elephant shrew is found in Central and East Africa from Northern Natal to Kenya and Northwest to the Congo river (Grizmeck 1990). It is also found on the Zanzibar and Mafia Islands (Nowak 1999).
Biogeographic Regions: ethiopian (Native )
Sometimes this animal is found in rocky areas, but usually it prefers thickets and dense forest undergrowth in caesalpinoid forests and woodlands (Kingdon 1997).
Habitat Regions: temperate ; tropical
Terrestrial Biomes: forest ; scrub forest
It is not known specifically for this species, but the average life span of elephant shrews in general in the wild is up to 4 years (Grizmek's 1990).
This elephant shrew has four toes on the hind foot as opposed to five, hence its common name. The animal is quite beautiful. Its grey to sandy fur is rather long and soft, and it has a touch of orange and yellow hues, sometimes with a wide dark strip on its back and white rings around the eyes. It is named, along with its relatives, for its long trunklike flexible nose used to find a variety of invertebrate prey hiding among the vegetation. However, unique to this species are the long skinny legs that hold the body 3 to 4 cm from the ground.
Elephant shrews are small mammals ranging in weight from 45 to 540 grams. However, the four-toed elephant shrew is one of the largest of the elephant shrews weighing 160 to 280 grams. Its body length ranges from 19 to 23 cm and its tail ranges from 15.5 to 17 cm (Grizmek 1990).
Range mass: 160 to 280 g.
Average mass: 205 g.
Range length: 19 to 23 cm.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 0.852 W.
This species is probably hunted by small carnivores, hawks owls and snakes. Avoidance of predators is most likely the reason for their choice of habitat. They are preyed upon by humans, who seek them to eat
Known Predators:
Mating System: monogamous
Monogamy is rare in mammals, but is well represented in this order. Most likely an abundance of resources and a monagamous mating sysem suggests a year round mating system.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 31 g.
Average number of offspring: 1.2.
The actual gestation period for this species is unknown but the range for other elephant shrews is 42 to 65 days. What is known for the four-toed elphant shrew is that there is one, sometimes two, young at birth that weigh about 32 grams (Grizmek 1990).The young are born in a highly precocial state, which allows them to run as fast as adults soon after birth (Nicoll and Rathbun 1990). Timing of weaning and sexual maturity is also unknown for this species but the range for weaning is 14 to 25 days and sexual maturity is 35 to 50 days for other elephant shrews (Grizmek 1990).
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The four-toed elephant shrew or four-toed sengi (Petrodromus tetradactylus) is the only living species in the genus Petrodromus, which together with five other extant genera Rhynchocyon, Macroscelides, Petrosaltator, Galegeeska and Elephantulus constitutes the order Macroscelidea.[1] This species is only found in particular regions in Africa and is smaller than its relatives.[3] A comprehensive record of this species is lacking.[1]
As its name suggests, the species has four toes on its hind feet,[4] and like other elephant shrews, it has been named for its elephant-like, mobile proboscis.[5]
The four-toed elephant shrew is located in Central and Southern East Africa, notably in Angola, Democratic Republic of the Congo, Kenya, Malawi, Mozambique, South Africa, Tanzania, Zambia, Zimbabwe, and possibly Namibia. Its natural habitats are subtropical or tropical dry forests, montane forests, and moist savannas.[2] Throughout these countries, they are the second most widespread species, following the short-snouted elephant shrew.[2][3]
Specifically, they thrive in dense forests (notably in dense evergreen growths), woodlands and thickets,[6] with suitable cover and protection, as well as invertebrates for food.[2] During the night, they prefer to sleep under dense brush (as opposed to a nest).[4]
In some areas, their habitats are being destroyed and four-toed elephant shrews are being hunted, but their conservation status is of least concern.[2]
A four-toed elephant shrew has long, soft fur and its color varies from greyish pale brown to dark brown with white rings around its eyes, and wide dark stripes on its back.[7]
Markings of the four-toed elephant shrew vary in colour: the upper parts of its feet are brownish-yellow; its ears are dark brown, with pure white hair on the base of the inner margin; the tail is black on the upper side and pale yellow-brown on the underside, darkening in the middle and almost black at tip.[2] The four-toed elephant shrew has a long, pointed, flexible and sensitive snout, which it uses to hunt.[8] It also has short forelimbs and long back limbs.[9]
The differences between the regular elephant shrew and the four-toed elephant shrew can be seen in facial features, body length and weight. Compared to the regular elephant shrew, which has small eyes and ears, a four-toed elephant shrew has broad, upstanding ears and large eyes. The elephant shrew generally varies in size from about 10 to 30 cm (4 to 12 in). [10] However, the body length of the four-toed elephant shrew is less variable, 19 to 23 cm (7.5 to 9 in).[4] Similarly, the tail length of the regular elephant shrew is 8.0 to 26.5 cm (3.1 to 10.4 in), while tail length of the four-toed species is 15.5 to 17 cm (6.1 to 6.7 in).[4]
The elephant shrew is a small mammal weighing from 45 to 540 g (1.6 to 19.0 oz), while the four-toed elephant shrew is one of largest elephant shrews, weighing between 160 and 280 g (5.6 and 9.9 oz).[4]
The four-toed elephant shrew is mostly active during the day and early evening, whereas during the night or midday, it tends to be less active.[3] When the four-toed elephant shrew runs, its tail points upwards; it also makes a noise through its hind feet.[11] Ants react to this sound, which helps the four-toed elephant shrew to locate its prey.
When four-toed elephant shrews fight, they usually fight in pairs of the same gender. They fight in a "boxing" motion, supporting themselves on their rear legs and boxing with their front limbs to tackle one another.[3] Four-toed elephant shrews have good senses of sight, smell and hearing, but their vocal capacity is not well developed. In captivity, they make different kinds of sounds, such as screaming, purring or clucking for help.[3]
Four-toed elephant shrews are heavily dependent on rich leaf litter composition for their food and nests.[6] Their main prey are small invertebrates.[4] Ants and termites are most common, as well as crickets, grasshoppers, spiders, centipedes, millipedes, and earthworms. Seeds, fruits, buds, and other plant material also form part of their diets. Four-toed elephant shrews eat much like anteaters; they flick small foods into their mouths.[6]
Based on where these four-toed elephant shrews live, their main diets can vary. In Kenya, their diets include termites, plant matter, centipedes, ants, crickets and cockroaches, millipedes, spiders, and other similar creatures.[3]
Some of the predators of the four-toed shrews are snakes, raptors, and carnivores, and in some cases, domestic cats.[3]
Depending on the quality of the habitat, four-toed elephant shrews breed throughout the year, showing an increase in reproduction when more feeding grounds are accessible.[10] The lowland forests and savannas offer shelter from the midday heat and resting places, as well as suitable birth places.[11] Copulation typically occurs on land, and they are monogamous in nature.[11] Their mating patterns involve sexual intercourse over several days, after which each mate returns to its solitary lifestyle.[10] Gestation lasts between 40 and 60 days and one or two offspring are born. The young are born in a highly developed state and are weaned by their mothers after 15–25 days; the young reach full sexual maturity close to 50 days after birth.[10] There are large granulated cells that occupy the walls of mesometrial and myometrial arteries. They are uterine natural killer cells. There is the persistence of a relatively larger yolk sac and large lobulated allantoic sac which is a feature shared with Petrodromus and other elephant shrews.
The four-toed elephant shrew or four-toed sengi (Petrodromus tetradactylus) is the only living species in the genus Petrodromus, which together with five other extant genera Rhynchocyon, Macroscelides, Petrosaltator, Galegeeska and Elephantulus constitutes the order Macroscelidea. This species is only found in particular regions in Africa and is smaller than its relatives. A comprehensive record of this species is lacking.
As its name suggests, the species has four toes on its hind feet, and like other elephant shrews, it has been named for its elephant-like, mobile proboscis.
