Thryonomys gregorianus individuals have poor eyesight, but good senses of smell and hearing. Vocalizations include whistling and low hooting grunts. They will also thump their hind feet when alarmed.
Communication Channels: tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
The ICUN Red List of Threatened Species lists lesser cane rats as a species of least concern due to their large population and wide distribution.
US Federal List: no special status
CITES: no special status
Thryonomys species can do considerable damage to sugar cane fields. Many plantations protect predators, such as pythons so that they can prey on cane rats, lessening crop damage. Cane rats also damage maize, millet, groundnut, sweet potato, cassava, and pumpkin fields.
Negative Impacts: crop pest
Thryonomys species are intensively hunted as an important source of protein throughout their range. They are typically hunted with dogs, spears, and fall-traps, or by burning vegetation. It is estimated that, in West Africa, 80 million are harvested annually, equaling 300,000 metric tons of meat. To increase meat availability, Thryonomys species have been domesticated and currently efforts are being made to expand the industry. Greater cane rats are preferred over lesser cane rats because of their larger body size, however it has been suggested that both species should be reared as part of the industry. Thryonomys species meat has more protein than chicken, rabbit, and guinea pig and lower fat than pork, beef, and lamb. The expansion of this domesticated market may also relieve pressure on wild populations of cane rats.
Positive Impacts: food
Lesser cane rats provide nutrition as a prey species to their predators. A species of anoplocephalid tapeworm, Thysanotaenia congolensis, was discovered in lesser cane rats in the Lake Kivv area of the Democratic Republic of Congo. They are the only known host for this species of tapeworm.
Commensal/Parasitic Species:
Lesser cane rats are herbivores that feed mainly on grasses and cane, but also feed on nuts, bark, fruits, and cultivated crops. They commonly gnaw on rocks, bones, and ivory. Lesser cane rat habitat is typically dominated by elephant grass and is therefore considered a principal food source. It is common for groundnut, sweet potato, cassava, maize, and pumpkin crops to be preyed on by these cane rats. Thryonomys gregorianus individuals also practice coprophagy.
Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit
Other Foods: dung
Primary Diet: herbivore (Folivore , Lignivore)
The genus Thryonomys is restricted to sub-Saharan Africa. Thryonomys gregorianus occurs throughout eastern Africa and into western Africa in the countries of Cameroon, the Central African Republic, Chad, the Democratic Republic of Congo, Kenya, Malawi, Sudan, Tanzania, Uganda, and Zambia. An isolated population also exists in Zimbabwe and Mozambique. It is likely that populations exist in Angola, however no records have been collected west of the Zambian border.
Biogeographic Regions: ethiopian (Native )
Lesser cane rats, occasionally referred to as savanna cane rats, inhabit moist grasslands dominated by elephant grass (Pennistum purpureum). They are also occasionally found along the fringes of swamps and in wooded areas. Individuals usually use tall grass for shelter, but have also been found digging shallow burrows or using rock crevices, termite mounds, and abandoned aardvark or porcupine holes. This species is considered non-aquatic, differing in habitat preference from the semi-aquatic Thryonomys swiderianus. Individuals have been recorded up to altitudes of 2,600 m.
Range elevation: 2,600 (high) m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: savanna or grassland
It is thought that Thryonomys gregorianus individuals rarely live past three years.
Range lifespan
Status: wild: 3 (high) years.
Thryonomys gregorianus is the smaller of the two extant species in the genus Thryonomys. Thryonomys swinderianus is the larger of the two species. Lesser cane rat body measurements are: average head to tail length 380 mm; average tail length 90 mm; and average hind foot length 59 mm. Body mass can range from 2.65 to 7.5 kg. Thryonomys species are covered with bristle-like hairs that grow in groups of five or six, and lay longitudinally along their bodies. They lack underfur. Typical body coloration is speckled grayish brown or yellowish brown on the back and flanks, with grey or whitish under parts. The tail is sparsely covered with short bristle-like hairs, with scales present between hairs. The tail is brownish above and whitish underneath. Ears are short, rounded, and hardly extend beyond the body pelage. The forefoot has three well-developed central digits, while the first and fifth digits are smaller and almost non-functional. On the hind foot the digits are larger, but the first digit is absent. Each foot possesses a naked palm and thick, heavy claws. Lesser cane rats have short tails that barely extend past their outstretched hind foot. This is a distinguishing characteristic from their close relative, T. swinderianus, which has a tail twice the length of the foot. Lesser cane rats have two paired mammae compared with three in T. swinderianus. The dental formula is: i 1/1, c 0/0, pm 1/1, m 3/3. Adult skulls can be identified by the placement of three groves on the anterior surface of each upper incisor. The third, outermost groove is located near the outside edge of the tooth, rather than along the midline of the tooth as in T. swinderianus. Most adult and juvenile skulls can also be differentiated from T. swinderianus skulls by the presence of a bar across each foramen ovale, a square appearance of the pair frontal bones when viewed dorsally, and a right angle orientation of the zygomatic arch and the dorsal and ventral attachments of the outer rim of the infraorbital foramen on the lateral side of the skull.
Range mass: 2.65 to 7.50 kg.
Average length: 380 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger
Predators include humans, servals, leopards, viverrids, pythons, and various birds of prey.
Known Predators:
Anti-predator Adaptations: cryptic
In Thryonomys species, males initiate courtship by wagging their tails and treading the hind legs. If the female is attracted to these actions, the pair will rear up and touch noses, followed by copulation. Male cane rats also use nose to nose pushing duels to establish a dominance hierarchy within in their social group, which presumably influences mate selection by females.
Mating System: polygynous
Although little is known about reproduction in T. gregorianus, in most regions they seem to be seasonal breeders, reproducing during the wetter months. Two litters a year are possible under favorable conditions. It is thought that Thryonomys species reach sexual maturity after one year. Scarce records show pregnant females carrying 2 to 3 fetuses. Gestation in Thryonomys lasts approximately three months. Due to this low reproductive potential, exploited populations may take long periods of time to recover.
Breeding interval: Two litters a year are possible under favorable conditions.
Breeding season: Breeding usually occurs during the wetter months.
Average number of offspring: 2-3.
Average gestation period: 3 months.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Thryonomys gregorianus young are born precocial, are active shortly after birth, develop rapidly, and are suckled by the female in grass nests (forms).
Parental Investment: precocial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The lesser cane rat (Thryonomys gregorianus) is a species of rodent in the family Thryonomyidae.[2] It is found in Cameroon, Chad, Democratic Republic of the Congo, Ethiopia, Kenya, Malawi, South Sudan, Tanzania, Uganda, Zambia, Zimbabwe, and possibly Mozambique. Its natural habitats are subtropical or tropical dry shrubland, subtropical or tropical dry lowland grassland, and shrub-dominated wetlands.
The lesser cane rat grows to a length of about 38 centimetres (15 in), about one quarter of which is the tail. Males are usually larger than females. The average weight of the lesser cane rat is 1.4 to 2.4 kg (3.1 to 5.3 lb) in males and 1.8 to 1.9 kg (4.0 to 4.2 lb) in females and they are a little less than half the size of the greater cane rat.[3] However, some males are as large as 3.5 to 5 kg (7.7 to 11.0 lb) about the size of an average greater cane rat.[4] The hair is coarse and rather bristle-like and lies flat against the body. The ears are small and almost hidden in the fur. The feet are long with three functioning toes, bare palms and strong claws. The back and sides of the animal are yellowish- or greyish-brown and the underparts greyish-white. The tail has a few bristles and scales and is brown above and white below.[5]
Its karyotype has 2n = 40 and FN = 80.[2]
The lesser cane rat is native to Central and East Africa and the more northerly parts of southern Africa. The main parts of its range are southern Sudan, the whole of Uganda, western Kenya, Tanzania, Zambia, Malawi and Zimbabwe but it also occurs sporadically in some of the neighbouring countries. It is found in open grassy countryside, the fringes of marshland and in woodland and it has been recorded at an altitude of 2,600 metres (8,500 ft) above sea level in the Rwenzori Mountains.[1] It occupies much the same range as the greater cane rat (Thryonomys swinderianus) but that species is more aquatic and frequents river banks and lakesides.[5]
The lesser cane rat is nocturnal and mainly moves around alone though it may live in a small family group. Though its eyesight is poor, it has a keen sense of hearing and individuals communicate with each other using grunts and whistles, and they may stamp their feet to warn others of danger. It is herbivorous and feeds on grasses, seeds, grain, fruit and other plant material. An important food item is often elephant grass (Pennisetum purpureum) but this rat is opportunistic and will also feed on crops such as peanut, maize, sweet potato, cassava and pumpkin.[5]
The breeding season is in the rainy season and there may be two litters in the year. The gestation period is about three months and the litter size is typically two or three young. These are precocial and are able to move around shortly after birth. They hide in nests in the grass where the female visits them at intervals to allow them to suckle. They become sexually mature at about a year and probably live three years.[5]
The lesser cane rat is assessed as being of "Least Concern" by the IUCN in its Red List of Threatened Species. Although the precise range of the lesser cane rat and its population trend are not known, it is a fairly common species and faces no specific threats. It is eaten as bushmeat in some parts of its range.[1]
The lesser cane rat (Thryonomys gregorianus) is a species of rodent in the family Thryonomyidae. It is found in Cameroon, Chad, Democratic Republic of the Congo, Ethiopia, Kenya, Malawi, South Sudan, Tanzania, Uganda, Zambia, Zimbabwe, and possibly Mozambique. Its natural habitats are subtropical or tropical dry shrubland, subtropical or tropical dry lowland grassland, and shrub-dominated wetlands.
