Colours of Wildlife: Greater Cane Rat
Created | Updated Oct 5, 2014
Greater Cane Rat or Grasscutter
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!"
This is a Greater Cane Rat, also known as a Grasscutter, Thryonomys swinderianus. The genus name means 'reed mouse' and the species name honours the Dutch professor Van Swinderen. Despite its name, it is not a rat or a mouse. It is a relative of porcupines, and most closely related to the Dassie Rat. Its fur is bristly but not spiny. There is one other species, the Lesser or Savannah Cane Rat, Thryonomys gregorianus. These two are the only members of the Cane Rat family, which is only found in Africa. Greater cane rats are quite large rodents, reaching 10 kg/22 lbs in weight and 80 cm/32" in length, although a more usual weight for it is 4.5 kg/10 lbs. It is the second largest rodent in South Africa, only the porcupine being bigger. If you look at it, you'll see it resembles South American rodents like capybaras and guinea pigs. Indeed, it is related to them – again more closely than to rats. The group it belongs to, the Hystricognaths, is far more diverse in South America than in Africa or Asia. Another, more specialized, group of rodents it is related to, is the African mole rats, which I'll feature here some time.
Greater cane rats usually inhabit marshlands or reed beds. They are stocky and powerful, with short tails and big, bulbous noses. Like other rodents they have very prominent incisors (front teeth) which in their case are orange in colour and with grooves along the front. They also have strong, sharp claws on their front and hind feet, for digging. Their 'fingers' are nimble so that they can hold on to grass blades and stalks while eating them. Their fur has a grizzled appearance, since there are darker and lighter bands on each hair.
Because of their plumpness, they are targeted by numerous predatory mammals and birds, and they usually keep themselves well concealed amidst the reeds and grasses. They cannot see well, but their senses of hearing and smell are excellent. They are active in the evenings, at night, and in the early morning. They sometimes occur singly but sometimes small groups share territories, communicating by soft grunts. When disturbed, they'll whistle loudly, and stamp with their hind feet if there's solid ground beneath them. They tread out visible trails among the grasses and reeds, these also being distinguished by the segments of chewed-off grass and reed stems that they drop while feeding, and piles of dung. Sometimes they forage in shallow water, using higher clumps of vegetation as dry resting places. They have dens hidden in the densest parts of the reedbeds, using leaves and stems as bedding. If there are no suitably heavily vegetated parts of the marsh to shelter in, they will use holes in riverbanks or under the roots of trees to shelter in. Only rarely will they dig out their own dens. Males use their bulbous snouts against each other in pushing and shoving contests. They can run surprisingly fast. They have the habit, when fleeing from a pursuer, of running a distance and then freezing, resuming with running only if the pursuer should approach them closely again. If they're in their dens, they're very reluctant to flee. They swim very well, and usually don't venture very far away from open water.
Like most other rodents, cane rates breed rather prolifically. In most of their range they can breed any time of the year. Females give birth to litters of up to eight, but usually about four. The babies are born fully furred and with open eyes. An hour after birth they can follow their mother. The female has nipples along the sides of her abdomen and suckle her babies while lying flat on her belly, or while standing up. Her babies are weaned in a month and reach sexual maturity in a year, and an adult female can give birth to two litters per year.
Cane rats are currently not threatened. Indeed, they are abundant and in some regions considered agricultural pests, eating crops like sugar cane, maize, manioc, eggplants, peanuts, potatoes and pineapples. They occur all over sub-Saharan Africa apart from dry regions. They are heavily hunted in some places, being esteemed as food, and also raised as semi-domestic animals. As far as I'm concerned they are underappreciated for their other important qualities. They are quite cute, and furthermore unique, being relatively 'primitive' and unspecialized compared to their relatives the porcupines, dassie rats and the diverse rodent assemblage of South America. But they have some specialized features of their own and are deserving of a lot more study.
