Golden bandicoot

Earlier studies have suggested that the golden bandicoot (I. auratus) is closely related to the southern brown bandicoot (I. obesulus), and they may in fact be the same species. Zenger et al. (2005) posited that mitochondrial DNA evidence suggested that these two species ought to be grouped into one species with three distinct subspecies, I. obesulus obesulus, I. o. peninsulae, and I. o. fusciventer. I. auratus would be included in the I. o. fusciventer subspecies. A third subspecies, I. a. arnhemensis has been recorded in Arnhem Land, NT, in the past, from the 1930s to 1980s, but this is now thought to be I. a. auratus. I. obesulus and I. auratus appear to have been allopatric ever since the Pleistocene. , the IUCN determines that I. auratus is a single species with no subspecies, while Isoodon peninsulae is a separate species. ==Distribution==

Range The golden bandicoot was once found across most of northern, central and western Australia, as far as south-western New South Wales to the east. However, numbers declined sharply within a few decades after European settlement of Australia, and was gone from the central deserts by around 1950. The largest golden bandicoot population lives on Barrow Island, because no cats or foxes have been introduced to the island, In 2000, it was assumed that the species was extinct on the mainland. Habitat The golden bandicoot lives in spinifex and tussock grasslands, and it used to be widely distributed in arid deserts and the surrounding semi-arid areas as well as tropical forests and woodlands. In Northern Kimberley, it is found along the margins of rainforests lined with sandstone, and in the Yampi Peninsula it inhabits eucalypt woodlands. On Augustus and Marchinbar Islands it lives amongst sandstone in hummock grassland and heath or eucalypt woodlands, and on Barrow and Middle Islands it is found in grasslands and coastal shrub. Its range once included the Gibson, Great Sandy, Great Victoria, Little Sandy, and Tanami deserts. It is believed that the golden bandicoot disappeared from the deserts between the 1940s and 1960s. Population numbers Individuals have a home range between , and the largest golden bandicoot population is on Barrow Island with about 20,000 individuals. In fact, it is the most common mammal on the island. On Middle Island it is estimated that there are about 1,000 individuals, and on Marchinbar Island there are roughly 1,400 individuals. On mainland Australia, populations are sparse, and most population declines have occurred there. ==Physical characteristics==

External anatomy The golden bandicoot is the smallest of its genus, and is distinguished from the more common northern brown bandicoots (Isoodon macrourus) by its much smaller size, golden colour and shape of its hairs, and its flatter, more elongated head. It averages about in length from head to tail and weighs with an average of . It is the smallest of the short-nosed bandicoots with a golden colour back, hence the name, finely streaked with black fur. The sides and face are a faded light rust colour, and the underbelly is pale amber. The feet are the same colour as the underbelly and have sharp claws. The species was first described in 1897 from a specimen collected near Derby, Western Australia. As with most bandicoots, the golden bandicoot has a rather long, flat, pointy nose. It is an omnivore, consuming succulents, insects, plant bulbs, and small reptiles. The golden bandicoot is nocturnal, foraging at night by digging small holes in the ground to find food. Measurements in the laboratory show that the golden bandicoot has a low body temperature that is constantly changing; in this sense it is heterothermic. This allows the internal body temperature to fluctuate in response to extreme environmental temperatures without inhibiting and denaturing necessary proteins. Additionally, it has a low basal metabolic rate, low thermal conductance, and low rate of evaporative water loss. A low metabolic rate correlates to less heat being produced by the body, and a low thermal conductance does not allow the golden bandicoot to capture and store heat well. A highly efficient panting mechanism allows for a low rate of evaporative water loss when cooling the body, conserving precious water. This is an indispensable advantage in arid and dry environments. ==Behaviour==

Foraging The golden bandicoot is nocturnal. During the day, it sleeps in dense vegetation or a hollow tree, making nests out of sticks, leaves, and grass. At night, it actively forages by digging shallow conical pits in the ground to root up succulents (their primary source of water), invertebrates, and plant roots. Because of this, its vision and sense of smell are highly developed, allowing it to see in low light and detect prey items by smell when digging. The golden bandicoot will also burrow in the soil if the temperature rises in order to keep cool. Reproduction Breeding occurs throughout the year and peaks during the wet season (December–January) and the dry season (August). Amongst marsupials, the golden bandicoot is known to have one of the highest reproductive rates, and it has one of the shortest gestation periods for mammals, only about 12 days. There are about 2–3 young per litter, and they remain in the pouch of the mother for up to 8 weeks. After this, there is little to no parental care, which allows the golden bandicoot to be such a prolific breeder. ==Threats==

Competition Several factors have contributed to the decline of golden bandicoot numbers throughout the century including introduced species, exotic predators, and loss of habitat. On Middle and Barrow Islands, competition with the introduced black rat (Rattus rattus) reduced golden bandicoot numbers significantly in the 1990s, but the black rat was successfully eradicated from these islands in 1993. Since then golden bandicoot numbers have increased five-fold. On Marchinbar Island, hair samples from the golden bandicoot have been recovered in scat samples from feral dogs, and Aboriginal people have been known to hunt them as well. Wild dogs were present on the Marchinbar until 2004 or 2005, when they were eradicated. The greatest threat to the species has been, and remains, feral cats. Habitat alteration Changes in fire regions have been cited as another major factor in the decline of the golden bandicoot. Reduced groundcover due to fires makes the golden bandicoot more exposed to predation, but it has been reported that the golden bandicoot prefers areas that have been burnt relatively recently, as these have fresh new vegetation close to the ground. ==Conservation==

Status With the last assessment done in 2012, the golden bandicoot was listed as vulnerable on the IUCN Red List. The mainland subspecies is listed as extinct under the Biodiversity Conservation Act 2016 (NSW) and Flora and Fauna Guarantee Act 1988 (Vic.), and as vulnerable under the Biodiversity Conservation Act 2016 (WA), In August 2023, the joint teams translocated 40 of the animals from the Charnley River-Artesian Range Sanctuary to the Newhaven Wildlife Sanctuary, which is located around north-west of Alice Springs. These would be joined by a further 60 bandicoots from Barrow Island the following week. ==In indigenous Australian culture==

The animal, known as Wan'kurra in the Yolngu language, features prominently in song-cycles in the ceremonies of the Gumatj people of Arnhem Land. It is a common motif in the work of artist Nancy Gaymala Yunupingu, often running through scrubland. It used to be referred to as "old people's food" by some Aboriginal people, because of their slow pace. ==Footnotes==