The Greater Cane Rat – Friend or Foe?

Several Simbithi residents have submitted photos of cane rats asking for the animals to be identified.  When Simbithi was still a cane farm they were probably considered a nuisance or pest but today, being a locally indigenous species, they are considered a friend on Simbithi.  We are unsure of how many we have on Simbithi as they are rather secretive and are only seen at night primarily in spring and summer.  Residents have reported seeing a pack of cane rats crossing the causeway between Weaver and Heron dams, a large pack of over twenty animals near South gate and a few were also spotted near Hornbill Dam. One evening I surprised a few on the link between Albizia Close and the Tamboti trail when doing a chameleon check as this links forms one of the three transects we use for monitoring chameleons on Simbithi.

The Greater cane rat (Thryonomys swinderianus) is more closely related to porcupines than to other rat species. They have coarse, flattened bristle like hairs with no under fur.   Their rounded faces also more closely resemble porcupines than rats. Greater cane rats have rather heavyset bodies with males having an average weight of 4.5 kg whereas 3.5 kg is the average for females. Their large incisors grow continuously, and I will never forget an experience I had about 40 years ago while working at UKZN.  Jen Maxwell, a friend who was busy doing her Master’s degree in Zoology, blindfolded me and led me into a room. There was the most deafening sound …….it sounded like hundreds of typists all enthusiastically bashing the keys of their typewriters simultaneously.  I could not begin to imagine what was producing the ear-splitting noise and was amazed when she removed the blindfold to see rows of cages each holding a cane rat or two who were busily devouring their lunch of reeds and sugar cane!

Also, unlike other species of rat, giant cane rats are herbivores and typically eat reed-like grasses, with elephant grass, Pennisetum purpureum, being a favourite. They prefer to live along riverbanks and in or near wetlands where the coarser reed grasses grow. The also prefer to breed when it is wetter but typically breed twice a year. After a gestation period of between 137 to 172 days a litter of four pups are born. The pups weigh about 130 grams when born and are relatively well developed as their eyes are open, they are covered in hair and can even run. Both males and females become sexually mature after a year and their life expectancy is estimated to be about four years.

A pack of cane rats is usually composed of one male, several females, and young from more than one generation.  They are nocturnal and create trails through grass and reeds that lead from shelter to feeding sites and water. They pound down tall grass to make nests and construct shallow burrows for shelter. They are good swimmers and divers. When threatened, they either stomp their hind feet and grunt or quickly run towards water.  Males have been observed fighting with other males by having a nose to nose pushing duel.

In some parts of Africa, the meat of cane rats is highly prized and fetches a higher price than chicken, beef or pork and they have been cited as a solution to Africa’s protein shortage. Not on Simbithi though, where we are not allowed to harm or slaughter wildlife!