| Elephant shrews | ||||||||||||
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Rhynchocyon Petrodromus Macroscelides Elephantulus | ||||||||||||
The small insectivorous mammals endemic to Africa known as elephant shrews are neither elephants nor shrews and, more formally, are the members of the biological order Macroscelidea. Their traditional common English name comes from a fancied resemblence between their long, prehensile noses and the trunk of an elephant, and an assumed relationship with the true shrews. As it has become more and more plain that they are unrelated to the shrews, it is likely that they will soon be known as sengis, a term derived from the Bantu languages of Africa.
The 15 species vary in size from about 10 cm to almost 30 cm, from just under 50 grams to over half a kilo. All are quadrupedal with rather long legs for their size, and although the size of the trunk varies from one species to another, all are able to twist it about in search of food. Their diet is largely insects and other small creatures, particularly beetles, spiders, worms, ants, and termites, mostly gleaned from leaf litter, but they also take seeds and some green shoots. The Rhynchocyon species also dig small conicial holes in the soil, Bandicoot style.
They are widely distributed across the southern part of Africa, and although common nowhere, can be found in almost any type of habitat, from the Namib Desert to boulder-strewn outcrops in South Africa to thick forest. One species, the North African Elephant Shrew, remains in the semi-arid, mountainous country in the far north-west of the continent.
Although mostly diurnal and very active, they are difficult to trap and very seldom seen: sengis are wary, well camoflagued, and adept at dashing away from threats. Several species make a series of cleared pathways through the undergrowth and spend their day patrolling them for insect life: if disturbed, the pathway provides an obstacle-free escape route.
The evolutionary history of the sengis has long been obscure. At various stages, they have been classified with the shrews and hedgehogs as part of the Insectivora; regarded as distant relatives of the ungulates; grouped with the tree shrews; and lumped in with the hares and rabbits in Lagomorpha. Recent molecular evidence, however, strongly suggests that the elephant shrews constitute a distinct order, Macroscelidea, and that their closest relatives are the other creatures in the proposed superorder Afrotheria: hyraxes, sirenians, tenrecs, golden moles, the Aardvark and—of all things—the elephants!
The oldest fossil sengis appear in the 50 million year-old rocks of the early Eocene, and by the Miocene the family had prospered and diversified into six separate subfamilies, and included both small, shrew-like insectivores and a wide range of herbivores. By the Pleistocene, all bar two subfamilies had died out.