Perception Channels: tactile ; chemical
T. swinderianus population is not threatened by extinction, although individual populations may be extinct locally due primarily to over hunting (National Research Council, 1991).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
T. swinderianus are considered to be great pests of many cultivated crops and can do great economical harm to farmers (Merwe, 2000).
Negative Impacts: crop pest
T. swinderianus is one of the most preferred meats in Africa and it can be more expensive than lamb, chicken, beef, or pork (National Research Council, 1991). It has been sold in Ghana markets for almost twice as much as beef and pork. In one African market, about 200,000 kg, which is worth about $220,000 U.S., was sold in a year’s time (Fitzinger, 1997). Asibey (1999) believes that if more research was done to find the most efficient way to breed T. swinderianus, then these animals would be the solution to Africa's protein shortage.
Positive Impacts: food
T. swinderianus are herbivores and their natural diet is mainly grasses and cane. Sometimes they also eat bark, fallen fruits, nuts and many different kinds of cultivated crops. Some of the cultivated crop fields that T. swinderianus invade are sugar cane, maize, millet, cassava, roundnuts, sweet potatoes, and pumpkins (Fitzinger, 1997). Great Cane Rats’ favorite food is elephant grass and sweet potatoes (National Research Council, 1991). They prefer plants with lots of moisture and soluble carbohydrates (Agbelusi, 1997).
T. swinderianus cut the grasses and other foods with their incisors, producing a chattering sound that is relatively loud and very distinguishable (Mills, 1997).
Plant Foods: leaves; wood, bark, or stems; seeds, grains, and nuts; fruit
Primary Diet: herbivore (Folivore )
Thryonomys swinderianus is common in Africa, south of the Sahara. It ranges from Gambia to southern Sudan and from south to north Namibia and South Africa. Its range does not include the southwest portion of South Africa (Fritzinger, 1997).
Biogeographic Regions: ethiopian (Native )
T. swinderianus is found naturally near marshes and river banks (Mills, 1997). Populations can also reach very high densities in plantations of cultivated crops (Merwe, 2000). Its habitat is expanding due to farmers turning once undesirable forest land into farmland (Asibey,1999).
Habitat Regions: tropical
Terrestrial Biomes: forest
Wetlands: marsh
Other Habitat Features: agricultural
Fritzinger (1997) desribed a T. swinderianus that lived in captivity for four years and four months.
Average lifespan
Status: captivity: 4.3 years.
Average lifespan
Status: wild: 4.3 years.
The body length of T. swinderianus is usually 350-610 mm, and their tail reaches 65- 260 mm in length (Fitzinger,1997). Great Cane Rats’ heavyset bodies have an average weight in males of 4.5 kg and 3.5 kg in females (Merwe, 2000). They have a rounded nose, short ears, and incisors that grow continuously (Mills, 1997). The pelage is coarse, with flattened bristle like hairs that grow in groups of five or six. The upper parts are a yellowish brown color and the underside is a much lighter gray. Great Cane Rats have no under fur (Fitzinger, 1997). The forefeet are smaller than the hind feet and have three well developed middle digits with the first and fifth digits greatly reduced. The hind feet have no first digit and all digits have heavy claws (Fitzinger, 1997). The dental formula for T. swinderianus is 1/1, 0/0, 1/1, 3/3 (Maerwe, 2000).
Range mass: 3 to 9 kg.
Average mass: 3.5-4.5 kg.
Range length: 350 to 610 mm.
Other Physical Features: endothermic ; bilateral symmetry
T. swinderianus live in groups of males and females during the breeding season. When the dry season comes males separate from the group and live by themselves. The females continue to live together (Fitzinger, 1997).
The breeding time depends on which part of Africa the animal is found and seems to depend on the weather (Fitzinger, 1997). The wet season of the year is the usual breeding season. Females generally have two litters per year with usually 4 offspring (Mills, 1997). Great Cane Rats estrous cycle usually lasts 6.62 days and they have a gestation period of 137- 172 days (Fitzinger, 1997). Offspring weigh about 129 grams and are relatively well developed. Their eyes are open, they are covered in hair and can run. T. swinderianus become sexually mature at about a year old (Fitzinger, 1997).
Range number of offspring: 1 to 6.
Average number of offspring: 4.
Range gestation period: 137 to 172 days.
Average gestation period: 155 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 129 g.
Average number of offspring: 4.
Average age at sexual or reproductive maturity (male)
Sex: male: 365 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 365 days.
Parental Investment: precocial
The greater cane rat (Thryonomys swinderianus), also known as the grasscutter (in Ghana, Nigeria and other regions of West Africa), is one of two species of cane rats, a small family of African hystricognath rodents.[2] It lives by reed-beds and riverbanks in Sub-Saharan Africa.
Greater cane rats can measure in head-and-body length from 43 to 60 cm (17 to 24 in) with the tail measuring 16 to 19.5 cm (6.3 to 7.7 in). Typical weight is 3.2 to 5.2 kg (7.1 to 11.5 lb), in males averaging some 4.5 kg (9.9 lb), and females at 3.4 to 3.8 kg (7.5 to 8.4 lb). In some cases, greater cane rats can weigh to approximately 7 to 9 kg (15 to 20 lb). They are considered one of the largest rodents in Africa, behind only the Hystrix porcupines.[3][4][5] It has rounded ears, a short nose, and coarse bristly hair. Its forefeet are smaller than its hind feet, each with three toes.
Cane rats live in small groups led by a single male. They are nocturnal and make nests from grasses or burrow underground. Individuals of the species may live in excess of four years. If frightened, they grunt and run towards water.
As humans expanded into the cane rat's native habitats, the cane rats likewise expanded from their native reeds into the plantations, particularly the sugar cane plantations from which they derive their name. Their tendency to adopt plantations as habitat, where they feed on agricultural crops such as maize, wheat, sugar-cane and cassava, often earns them the label of agricultural pest. However, the peoples of the region also utilize the cane rat as a food source (as bushmeat), considering the meat a delicacy. Consequently, these rats are beginning to be raised in cages for sale.[6]
The greater cane rat (Thryonomys swinderianus), also known as the grasscutter (in Ghana, Nigeria and other regions of West Africa), is one of two species of cane rats, a small family of African hystricognath rodents. It lives by reed-beds and riverbanks in Sub-Saharan Africa.
