The average life span of A. rufescens is greater than five years, and captive animals have been known to live for eight years (Nowak, 1997).
Distribution over the known range is discontinuous and may be contingent upon food and shelter availability. It is believed that the former range of A. rufescens was more expansive prior to European occupation, extending even further south into northeastern Victoria. Remains of these creatures have also been found in southwestern Victoria and on Flinders Island near Tasmania (Nowak, 1997). Theories as to the cause of this species' declining range include the introduction of and subsequent predation by foxes, agricultural land clearing and cattle grazing, as well as long-term climatic fluctuation (Johnson, 1983; Nowak, 1997; Troughton, 1962).
Aepyprymnus in their natural habitat are not afraid of humans at night.
Perception Channels: tactile ; chemical
Aepyprymnus rufescens currently is common (Straham, 1995), although the range has been reduced. The IUCN Red List Category is given as Low Risk (Biodiversity Group, 1996).
IUCN Red List of Threatened Species: least concern
Aepyprymnus rufescens can become an irritating pest for crop farmers. During the dry season especially, they will eat plant roots, including potatoes and other tubers.
When taken at a young enough age, these animals can be tamed as pets.
Aepyprymnus rufescens emerges shortly after sunset to begin its search for food. Aepyprymnus eats a variety of grasses, herbaceous plants, and uses its well-adapted foreclaws to dig for roots, tubers, and underground fungi. These animals can eat entire plants including seeds, flowers, and leaves, however they are not strictly herbivorous (Strahan, 1995). Aepyprymnus occasionally chews on the bones of dead animals and digs larvae out of the ground to eat. In captivity they will accept a variety of foods. Aepyprymnus rufescens can extract enough water from this diet to forego drinking altogether except in times of drought, when it excavates a hole in creek beds to attempt to reach the water level for a drink (Nowak, 1997).
Aepyprymnus rufescens is the most widely distributed potoroid of the Australian region, ranging from northeastern Queensland to northeastern New South Wales. A colony can also be found on the border between New South Wales and Victoria, and occasionally along the northern Australian coast (Nowak, 1997; Ride, 1970).
Biogeographic Regions: australian (Native )
Aepyprymnus rufescens live predominately in open, temperate conditions from sea level to plateau tops. They thrive in grassy woodlands, coastal eucalypt forests, wet sclerophyll, and in low dry open woodlands with grassy understorey (Strahan, 1995). All A. rufescens build conical-shaped nests that have one entrance. Nests can be found in the hollows of fallen trees, under bushes, in grass clumps, or more rarely in open ground. Aepyprymnus rufescens use materials such as grass, hay, straw, dry ferns, and fibrous vegetation to build their nests. They pick this material up with their forepaws and pass it down the body to the tail which places the material in the nest. Replacement grass is arranged in the nest by lifting up older building material with the nose to create space. Aepyprymnus rufescens use up to five nests at any one time, and it has been proposed that nest building may only occur in the winter. On a monthly basis new nests are added as old nests are abandoned, and abandoned nests may be rebuilt and used by a neighboring A. rufescens.
Terrestrial Biomes: savanna or grassland
Average lifespan
Status: wild: 6.0 years.
Average lifespan
Status: captivity: 8.0 years.
Aepyprymnus rufescens is the largest living secies of rat kangaroo. Adult males weigh between 2.27kg and 3.0kg; adult females weigh between 1.36kg and 3.6kg. Body length ranges from
37.5cm to 52.0cm; tail length from 35 to 40cm; total length from 72.5cm to 90.0cm; and height approximately 35.0cm.
The name "rufescens" refers to the animal's reddish-brown coat color. This pelage is often described as grizzled, containing stiff, sliver-white hairs. Its hair-covered snout and the black hair on the back of its ears further distinguish this species. Aepyprymnus rufescens has a very faint whitish hip stripe, and its underside is noticeably lighter than the dorsal side (Troughton, 1962). The curved foreclaws of this species are well adapted for the scratching and excavating that aid in its food gathering. The hindfoot of A. rufescens lacks the first toe, and the third digit is proportionately longer than the rest (Strahan, 1995). The tail is semi-prehensile, thick, and evenly haired.
The skull of A. rufescens is short and broad compared to other potoroids. The frontal bone articulates with the squamosal region of the temporal bone, and the angular process forms a prominent shelf. Palatine fenestration varies within the species, however fenestrae are remarkably smaller or absent in the A. rufescens as compared to other potoroids. Aepyprymnus rufescens has a dental formula 3/1, 1/0, 1/1, 4/4. The first upper incisors are long, sharp, and blade-like. The second and third upper incisors are smaller and laterally displaced (Triggs, 1996). Characteristic of Diprotodontia, the first lower incisors project forward from the dentary. Diastemae are present but reduced, and canines appear in the upper jaw. The premolar is plagialaucoid; the molars erupt at approximately the same time and are bunodont (Ganslosser, 1990; Triggs, 1996).
Range mass: 1.36 to 3.6 kg.
Average mass: 0.00248 kg.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 5.978 W.
Aepyprymnus rufescens is polyestrous, with an estrus cycle occurring approximately every 34 days. Breeding can occur at any time during the year, but there is insufficient data from both captive and wild species to indicate a particular breeding season. Females reach sexual maturity in the 11th month, males between 12 and 13 months. Males visit female nests within their territory every night to determine if the female is sexually receptive. As the female approaches ovulation, the male waits either by the female or by her nest until she is sexually receptive. Both sexes can let out low growls during investigational behavior, which usually includes sniffing of the female by the male. A receptive female allows the male to smell her cloacal and pouch areas, and eventually permits copulation (Ganslosser, 1990).
Males will try to mount the female regardless of warning signals exhibited by unreceptive females. These females try to drive away courting males by making loud growling sounds, striking at the male with her forepaws, and dropping to her side and kicking at the male with her powerful hindlimbs (Ganslosser, 1990). In response to this attack, A. rufescens males often stamp one outstretched hind foot near the female and thresh their tails.
Once successful copulation has been achieved, the embryo has a gestational period of 22-24 days. After this time the embryo is born and affixes itself to one of the mother's four teats found in her pouch. The newborn young weighs approximately 1g at birth. Within one day of parturition, the female will mate again to produce a quiescent blastocyte. The newborn will remain in the pouch for approximately 114 days (7-8 weeks) before it is weaned. Aepyprymnus rufescens do not permanently leave the pouch until the 16th week. The juvenille animal stays with its mother for the ensuing seven weeks while it learns to feed, is groomed and shares its mothers nest. Aepyprymnus rufescens normally have one young per birth, however twins are not uncommon.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average gestation period: 23 days.
Average number of offspring: 1.
Average age at sexual or reproductive maturity (male)
Sex: male: 380 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 333 days.
The rufous rat-kangaroo or rufous bettong (Aepyprymnus rufescens) is a small, jumping, rat-like marsupial native to eastern Australia. It is the only species in the genus Aepyprymnus. The largest member of the potoroo/bettong family (Potoroidae), it is about the size of a rabbit. The rufous rat-kangaroo is active at night when it digs for plant roots and fungi, and like other marsupials it carries its young in a pouch. Though its range is reduced, the population is healthy and stable.[2]
The rufous rat-kangaroo is the only member of its genus, and is the largest of all the potoroids. It is generally grey with a hint of reddish brown and its scientific name means "reddish high-rump".[5] It was once thought of as a solitary, nocturnal animal, but recent observation indicates that the rufous rat-kangaroo may form loose, polygynous associations.[5] It feeds mostly on tubers and fungi, but also on leaves and other vegetation.[6]
A species of the family Potoroidae (potoroos & bettongs), small to medium marsupials that include the living Potorous (potoroos) and Bettongia (bettongs). They are not closely related to others of the family, and the largest extant potoroine species, and their characteristics have them placed within a monotypic genus.
Aepyprymnus rufescens is distinguished by the ruffled and bristly hair of the pelage and rufous tint of the fur at the upper parts. The hair across the back is predominantly grey, the rufous tinge more evident, and is interspersed with silvery hairs. An indistinct stripe appears at the hip line. The underparts are also grey, although paler. The combined head and body length is 385 to 390 millimetres. The tail may be from 340 to 390 mm in length, and excepting a white tip that may appear the colour is overall grey-brown. The ears are comparatively long, 48 to 57 mm, with a triangular form. The colour of the ears is very dark at the outer side and pink at the interior, the fringe is lined with silver hairs. A hairless pink rim appears around the eye. The weight range is from 2.5 to 3.5 kilograms.[7]
A similar species, the northern Bettongia tropica, may be distinguished by the lack of shaggy fur with a rufous tinge, their blackish tail, and this species hairless pink ring at the eye and pointy triangular ears.[7]
The vocalisation includes an alarm call, a soft hissing sound, another sound like a chainsaw when in aggressive postures and they regularly emit a grunting noises during normal activity.[7]
Breeding occurs throughout the year, once the female has reached maturity, generally at 11 months. The male reaches maturity between 12 and 13 months. Once mature, the female is capable of breeding at three-week intervals. The gestation of the young is about 22–24 days. After the young are born, they live within the pouch for about 16 weeks. Upon leaving the pouch, the joey stays near the mother for about 7 weeks, while it gets used to fending for itself.[5]
The species may share nests or be solitary, a male may cohabit with one or two females. The nest is located beneath a dense under-story of vegetation, a shallow clearing that is matted with woven plant material. The foraging activity is strictly nocturnal, they will only emerge after sunset and return to the nest before first light. The posture varies with the activity of the species, assuming an upright position on the hind parts to survey its surroundings, drawing the forelimbs to the chest when hopping rapidly away from a threat, and resting on all four limbs and the tail when slowly moving during feeding.[7]
The favoured foods are subterranean fruiting bodies of fungi and tubers, and the species have strong clawed forelimbs that allow them to excavate these. Other foodstuffs consumed include some insect larvae, the stems of sedge-like plants, grasses and seeds.[7]
The museum collector Charles M. Hoy noted that the species entered his camp at night, eating pieces of bread but ignoring the vegetable scraps.[8]
It is found in coastal and subcoastal regions from Newcastle in New South Wales to Cooktown in Queensland, and was formerly found in the Murray River Valley of New South Wales and Victoria.[7][6]
The rufous rat-kangaroo or rufous bettong (Aepyprymnus rufescens) is a small, jumping, rat-like marsupial native to eastern Australia. It is the only species in the genus Aepyprymnus. The largest member of the potoroo/bettong family (Potoroidae), it is about the size of a rabbit. The rufous rat-kangaroo is active at night when it digs for plant roots and fungi, and like other marsupials it carries its young in a pouch. Though its range is reduced, the population is healthy and stable.