Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Today I bring you a mousie! Actually, it's a gerbil: a Bushveld Gerbil, Tatera leucogaster, to be exact. These little rodents are native to my part of South Africa. The 'bushveld' is what we call the hot, dry-ish tree and bush savannahs that are the natural vegetation of the northeastern parts of the country. A closely-related species is the Highveld Gerbil, the highveld being the high-lying grassland in the interior of the country. Actually, the two species overlap considerably, with the bushveld gerbil also inhabiting some treeless grasslands, and the highveld gerbil also occurring in more densely wooded and low-lying regions. Because gerbils are very hard to identify in the field, I can't say for sure if I've seen the bushveld or the highveld gerbil, or maybe both, but I've seen at least one of them. The bushveld gerbil reaches about 28.5 cm/11.5" in overall length, slightly more than half of which is its tail. It weighs about 70-110 g/2.5-3.9 oz. It has dense, sleek, soft, tawny-brown fur, with individuals from dryer areas generally being lighter in colour than ones from more moist regions.
So let's sort out some of the confusion around gerbils! Many people confuse gerbils with hamsters, when kept as pets. Hamsters are round, chubby-looking, short-tailed rodents. Gerbils tend to be a bit sleeker in build, and most species have long tails. Their tails are typically rather hairy, rather than naked and scaly. Gerbils have enormous eyes, because they're mainly nocturnal, which is why we call them 'nagmuise' ('night mice') in Afrikaans. They are indeed mice, in the same family as many species of 'conventional' mice and rats (biologically there's not really any meaningful distinction between a mice and a rat, just size, and there's a huge 'grey area' where that is concerned) but in a separate subfamily, the Gerbilinae. They also typically have very long hind legs, like tiny kangaroos. The use these to leap about, but they don't hop on their hind legs only as kangaroos do, instead coming down on their forelegs in the manner of hares and rabbits.
The gerbils as a group likely first appeared in Asia, on the forbidding steppes of the deep interior, where they have to deal with regular drought as well as extremes of both heat and cold. They live in holes and burrows, some of them in small gerbil societies, to escape both heat and cold. Many kinds also collect and store food in their burrows, helping them survive tough times. They are quite omnivorous, eating plant as well as insects and other invertebrates. They entered Africa perhaps about 7 million years ago, fossil gerbils of that age having been found, and have diversified greatly here. Many of them still inhabit desert regions, even the barren Sahara and the ancient Namib, but some also live in places with lush vegetation.
The genus Tatera includes about eleven gerbil species that are restricted to Africa south of the Sahara. Of these, the bushveld gerbil is one of the most widespread. It occurs from the northern half or so of South Africa into our neighbour countries of Mozambique, Zimbabwe, Botswana and Namibia, and further north as far as the southern DRC and Tanzania. Over this huge range it can be found from semi-deserts receiving less than 100 mm/4" of rainfall, into lush savannahs and open woodlands, from sea level to an altitude of 1 600 m/5 300'. It lives mostly in places with somewhat sandy soil, but sometimes on harder soil. While it digs its own burrows in softer soil, in hard soil it will use holes already provided, such as in termite hills or hollows beneath exposed tree roots. It is apparently not a social species, but mated males and females share burrows. These are about 40-45 mm/1.6"-1.8" in diameter. A little pile of freshly-dug earth is usually visible at the entrance. Apparently every evening, the residents clean out the burrow. Underground there can be a few tunnels branching off the main one, with resting chambers at the ends. These are furnished with comfy 'beds' made of dry leaves on which the gerbils sleep. Unlike some other gerbils, bushveld gerbils don't hoard food. They eat mostly plant seeds, but also leaves, fruit, roots and bulbs, and a significant amount of invertebrates.
Like many rodent species, bushveld gerbils can be prolific breeders. Though the breeding season is largely dictated by rain, which in South Africa falls mainly in the summer, they can have litters at any time of the year. Typically the female gives birth to two to nine babies, with an average of four to five. They're born hairless in the burrow, where the female takes good care of them. They grow quickly and will eventually remain with their parents in the burrow system, only moving out later. In years of abundant food, these gerbils can multiply rapidly, but their numbers crash in poor years.
Bushveld gerbils are abundant all over their huge range, and not at all threatened. They are sometimes considered pests, actually not because of destroying crops, but because they are carriers of the bubonic plague bacillus, Pasteurella pestis. Being wild animals, they don't actually come into contact with humans much, but they may transmit the disease via fleas to other rodents, such as the multi-mammate mouse, which do come into houses where the fleas may end up transmitting the plague to people. But it's European people who brought the plague into Africa in the first place, by way of the rats which came along with them on their ships during the ages of exploration. The rats subsequently spread the disease to our indigenous rodents. The first outbreaks among humans in southern Africa only happened at the very end of the Nineteenth Century, and there have been several since. Nevertheless, these have never even remotely reached the dimensions of the big plague outbreaks of Europe and Asia. Thankfully, bubonic plague doesn't seem to have done much recently.