30 Oct The Fat Mouse
Seen a Fat mouse recently? No, not a rather small, rotund rodent but specifically a fat mouse, which is the common name for Steatomys pratensis. This mouse, which occurs in northern South Africa, Zimbabwe and many other parts of Africa is closely related to the tiny fat mouse, Steatomys parvus which is also a really small rotund rodent. Then there is of course Kreb’s fat mouse Steatomys krebsii.
All three are roughly about nine centimetres long, with their tails adding a further four and a half centimetres, and they are called “fat” because they store large amounts of fat just under the surface of their skin which, unfortunately for the mice, makes them a delicacy for many people in Africa. They are often sold at roadsides in the form of a shish kebab (sosatie) with several roasted mice impaled on a stick.
The stored fat serves as a food source for the mice during the winter months when they go in torpor, a state where they reduce their body temperature and slow down their body functions. All three species feed on a variety of seeds but also eat insects,
Altogether 32 species of mouse occur in southern Africa south of the Zambezi River. There are also four species of dormouse which differ in various ways from other mice but the most noticeable variation is their bushy tails.
Mice are very successful creatures and as a family live in a wide range of habitats. Although generally much smaller than rats, from which they differ in a number of physiological aspects, they occur almost everywhere in the region but some have very specific habitat requirements and are found in specialised localities.
Shortridge’s rock mouse, for example, only occurs in a small area of northern Namibia and Grant’s rock mouse is restricted to the arid Karoo region of South Africa.
Although at first glance many mice appear similar some have very specific characteristics. The Large eared mouse has, unsurprisingly, noticeably large ears and the Spiny mouse, which occurs in the northern parts of South Africa and most of Zimbabwe, has fur which is rough and spiky to the touch.
Mice help disperse plant seeds though their habit of creating of food hoards, spread fungi through their droppings and to a degree aerate soils by making burrows.
Mice are eaten by a very wide range of predators, consisting of mammals, (including humans) birds and reptiles. Even animals as large as leopards or birds the size of eagle owls will catch and eat mice.
Rodents are the most plentiful and successful of all mammals with somewhere between 1775-1800 species worldwide. About 80 species are found in South Africa. These include mice, rats, mole rats, gerbils, the springhare and the porcupine, Africa’s largest rodent.
The Complete book of Southern African Mammals – Lex Hes and Gus Mills