There are 7 species of Short nosed bandicoots. The life expectancy of Isoodon obesulus is 2.5 to 3 years.
(Macdonald, 1984; Nowak, 1991)
Perception Channels: tactile ; chemical
Many species of bandicoot have already gone extinct due to habitat loss caused by grazing livestock. Many other species including Isoodon obesulus, are in great danger. In Australia the decline of bandicoots is worse than the decline of any other marsupial. (Macdonald, 1984)
IUCN Red List of Threatened Species: least concern
Isoodon obesulus are omnivores. They feed on soil invertebrates and insects as well as fruits, seeds, fungi, and some plant fibers. They favor insects and worms. Isoodon obesulus use their sharp claws and pointed noses to dig for food. They use their front legs to repeatedly step on prey that is captured in order to crush it. (Macdonald, 1984; Nowak, 1991)
Isoodon obesulus inhabits several different geographic ranges. There are populations in eastern New South Wales, southern Victoria, southeastern south Australia, Kangaroo Island, southwestern western Australia, The Recherche Archipelago, Tasmania, and West Sister Island in Bass Strait. (Nowak, 1991)
Biogeographic Regions: australian (Native )
Isoodon obesulus prefer dense ground cover, tall grass and low shrubbery. They live near swamps and rivers as well as in thick scrub in drier areas. They make their nests on the ground and in logs. The nests consist of sticks, leaves, grass, and soil. (Macdonald, 1984; Nowak, 1991)
Terrestrial Biomes: savanna or grassland
Average lifespan
Status: captivity: 6.5 years.
Short nosed bandicoots are plain looking animals, similar in size and shape to rats and rabbits. The species obesulus has a shorter snout than other species of bandicoot, but it is still elongated for foraging. They have short rounded ears and sharp claws. The short nosed bandicoot has several colors in its fur. The upper part of the fur is usually blackish brown with hints of orange or yellow, while the underside is lighter brown, grey, or white. The short nosed bandicoot has a pouch that runs along the stomach and opens backwards between the hind legs. (Nowak, 1991)
Range mass: 1.1 to 1.4 kg.
Other Physical Features: endothermic ; bilateral symmetry
Average basal metabolic rate: 1.238 W.
Short nosed Bandicoots have pouches that are characteristic of most marsupials. Females carry their babies in these pouches for about 50 days after they are born. Bandicoots can reach sexual maturity as early as 90 days of age. Bandicoots are polyestrous, which means that they are able to reproduce several times a year. The gestation period in this species is only 12.5 days. This gives Bandicoots the highest reproductive rate of all marsupials. Typically there are 4 babies in the pouch at one time, but up to 5 have been found. (Macdonald, 1984; Nowak; 1991)
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
Average birth mass: 0.35 g.
Average number of offspring: 2.73.
Average age at sexual or reproductive maturity (female)
Sex: female: 210 days.
The southern brown bandicoot (Isoodon obesulus) is a short-nosed bandicoot, a type of marsupial, found mostly in southern Australia. A subspecies in Western Australia was also known as the quenda in South Western Australia (from the Noongar word 'kwinda').[6]. This subspecies was elevated to species in 2018.[7]
George Shaw described the species as Didelphis obesula in 1797. While some authorities list as few as two subspecies (I. o. obesulus and I. o. nauticus), there are currently five recognised species:[3]
Southern brown bandicoots have a stocky body with a short snout and short, rounded ears. They show sexual dimorphism, with females being smaller than males. On average, males measure 50 cm (20 in) in total length, and weigh up to 1.2 kg (2.6 lb), while females measure 40 cm (16 in) and weigh no more than 1 kg (2.2 lb). They have coarse, bristly hair that is grizzled and coloured a dark greyish to yellowish brown, with the undersides a creamy-white or yellowish grey. The tail is relatively short, measuring about 13 cm (5.1 in) in length, and is brown above and white below.[6][5]
There are five toes on each foot, although, as in many other marsupials, they are syndactylous, with the second and third toes of the hind foot are fused along almost their entire length. The toes end in sturdy claws, except for the first digits of the fore feet and the fifth digits of the hind feet, which are tiny are vestigial. The pouch in females opens to the rear, and contains eight teats arranged in a partial circle.[5]
Once common throughout many parts of coastal Australia, today southern brown bandicoots have a more limited distribution. An isolated population exists at the north-eastern part of the Cape York Peninsula in Queensland, but all other surviving animals are found in the southern half of the country. In New South Wales they are considered rare, and are primarily restricted to the extreme south-east of the state and to two national parks north of Sydney. In Victoria, they are more common, being found along the whole length of the coast and at up to 1,000 m (3,300 ft) in the Grampian and Dandenong mountains.[5]
In South Australia, they inhabit the Eyre and Fleurieu peninsulas, the extreme southeast, and Kangaroo Island.[9] Isolated and increasingly restricted populations are known from south-western Western Australia.[3] However, southern brown bandicoots are most common in Tasmania, where they are found across almost the entire island. They are also currently found on Inner Sister Island but have been extirpated from many other small Tasmanian islands where they once lived.[5]
Within these regions, southern brown bandicoots inhabit open forest, scrub, and heathland, especially where there is extensive ground cover by shrubs or mat-rushes.[5][10] I. o. obesulus has shown a preference for the margins of artificial waterways over drier habitats.[11]
Southern brown bandicoots are nocturnal and omnivorous, feeding on insects, spiders, worms, plant roots, ferns, and fungi.[10] They spend very little time drinking, being able to obtain sufficient water from their diet alone.[12] Although their native predators include barn owls, tiger snakes, and quolls, the bandicoots do not avoid the odour of these animals, which may make them vulnerable to predation.[13] They do, however, typically avoid one another, living solitary lives in non-overlapping home ranges that typically vary from 1 to 5 hectares (2.5 to 12.4 acres), depending on the local conditions. If males encounter one another, the more dominant individual leaps onto the back of the other, scratching with its claws. Because the skin of bandicoots is unusually thick, this results in hair loss, but little permanent injury to the defeated male.[5]
They spend much of the night searching for food, which the detect primarily by scent, sniffing the ground before digging into with their claws. They pursue any prey that escapes, holding it down with their forepaws as they consume it. The digging behaviour is considered a critical component in the maintenance of the ecosystems in which they live. It is estimated that a single bandicoot displaces around 3.9 tonnes of soil each year.[14] They spend the day sleeping in well-concealed nests of shredded vegetation.[5] Both sexes possess scent glands between the ears that are apparently used in intra-species communication and become enlarged during the breeding season.[15]
The Southern brown bandicoot is a host of the Acanthocephalan intestinal parasite Australiformis semoni.[16]
Reproduction is closely linked to local rainfall pattern, and many brown bandicoots breed all year around, giving birth to up to four litters a year.[17] Gestation lasts less than fifteen days, and perhaps as few as twelve, and typically results in the birth of two or three young, although litters of up to five have been reported;[5] larger mothers tend to give birth to larger litters.[18]
The young weigh just 350 mg (5.4 gr) at birth, remain in the pouch for about the first 53 days of life, and are fully weaned at around 60 days. Growth and maturation is relatively rapid among marsupials, with females becoming sexually mature at four to five months of age, and males at six or seven months. Lifespan in the wild is probably no more than four years.[5]
The southern brown bandicoot is currently classified as Least Concern by the IUCN.[2] However, populations have declined markedly and become much more fragmented in the time since European expansion on the Australian mainland. In many areas of its range the species is threatened locally, while it may be common where rainfall is high enough and vegetation cover is thick enough. Apart from habitat fragmentation, the species is under pressure from introduced predators such as the red fox and feral cats.[2] It has been reintroduced to some lower rainfall areas where there is protection against cat and fox predation – one such site being Wadderin Sanctuary in the eastern wheatbelt of Western Australia, 300 km east of Perth.
In national assessment, the southern brown bandicoot is currently regarded as Endangered on the mainland as a whole, and Vulnerable in South Australia.[19]
The southern brown bandicoot (Isoodon obesulus) is a short-nosed bandicoot, a type of marsupial, found mostly in southern Australia. A subspecies in Western Australia was also known as the quenda in South Western Australia (from the Noongar word 'kwinda').. This subspecies was elevated to species in 2018.