Roundeared sengi

Macroscelides proboscideus

SUBFAMILY

Macroscelidinae

TAXONOMY

Macroscelides proboscideus (Shaw, 1800), Roodeval, Oudtshoorn Division, Cape Province, South Africa.

OTHER COMMON NAMES

English: Short-eared sengi, jumping shrew; French: Macroscelide d'Afrique du sud, rat à trompe d'Afrique du sud; German: Kurzohr-rüsselspringer; Afrikaans: Ronde-oorklaasneus.

PHYSICAL CHARACTERISTICS

The round-eared sengi is among the smallest of the living sengi species. The adult head and body length runs 3.5-4.5 in (95-115 mm), the long tail adding another 4-5.5 in (97-135 mm). Adult weight is 1-2 oz (30-50 g). The body fur of the animals is long, dense and soft, hued orange, brown, or gray on the upper body or dorsal area and whitish on the under-parts or ventral area. The tail bears coarse, black fur. The skin at the base of the tail is pink or dark. The limbs bear short, white fur. The body fur is two-colored throughout, the tips of hairs colored and the bases dark. Fur colors vary widely throughout the range of the species.

All four feet have five toes each, and on the hindlimbs, the hallux, or equivalent of the big toe, is set off from the others. All the digits have small, dark claws.

The head bears large, limpid, dark eyes that lack the pale, surrounding ring seen in other sengi species. The characteristic long, mobile snout is covered with short, white fur. The nostrils, at the nether tip of the snout, are set in dark, wet, furless skin. The ears are rounder and shorter than in other sengi species, and are backed and bordered by fur, providing signs diagnostic of the species. The skull has almost grotesquely inflated auditory bullae, or inner ear chambers of bone, indicating the importance of hearing in the species. The female has six mammae.

DISTRIBUTION

Round-eared sengis live throughout Namibia, Cape Province in South Africa, and southern Botswana. In Great Namaqua-land, South Africa, the ranges of the round-eared sengis and Elephantulus rupestris, the Western rock sengi, overlap.

HABITAT

The preferred habitat for Macroscelides proboscideus is desert, semidesert, and scrub forest.

BEHAVIOR

Despite also being called "jumping shrews," round-eared sengis rarely jump, preferring to walk or run, carrying their tails horizontally. They can run with speeds up to 12.4 mph (20 km/h), quite impressive for such a small creature. Individuals hide in sparse grass cover or bushes, and can quickly burrow into the sand for protection.

Individuals live solitarily in home ranges that may reach 2.5 acres (1 ha) and include foraging areas and way-shelters. The shelters are short burrows located under stones, roots, or bush. Sengis can and will enlarge their refuge rapidly by digging. The burrows have a main entrance/exit and an emergency exit, the latter inconspicuous. Round-eared sengis also take refuge in deserted shelters of suricates (Viverridae) or gerbils (Gerbill-idae), fastidiously cleaning their new homes of sand, gravel, and other detritus.

During the day, round-eared sengis may nap in the sun, sitting on their haunches, still alert for the slightest hint of danger. They also sand-bathe, wallowing in pre-established patches of dry sand, to scent-mark and to clean their coats.

FEEDING ECOLOGY AND DIET

Round-eared sengis are primarily crepuscular (twilight) and nocturnal foragers. They start foraging at twilight, then continue through most of the night, sniffing with their mobile snouts in crevices between stones, under roots, and in carpets of fallen leaves. Although mainly insectivorous, with a preference for ants and termites, they also eat other small invertebrates and plant material, including roots, shoots, and berries. The round-eared sengi can be considered a functional omnivore, since at least half of its food intake is often plant material, balanced by invertebrate food.

REPRODUCTIVE BIOLOGY

Although solitary most of the time, individual males and females pair up in the mating season and stay together for several days, defending their territory sex-specifically. There is a distinct breeding season, in August and September, which are warm, wet months in southern Africa.

The one or two young are born precocial, able to run a few hours after birth. The female bears and keeps her young in a hideaway separate from the parents' burrow, stopping by once a day to nurse them. The young are weaned at 16-25 days and reach sexual maturity at about 43 days.

CONSERVATION STATUS

Due to destruction of its habitat, Macroscelides proboscideus is listed as Vulnerable by the the 2002 IUCN Red List of Endangered Species.

SIGNIFICANCE TO HUMANS

There is no known significance to humans. ♦

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