The golden bandicoot (''Isoodon auratus'';
Yolngu: ''Wan'kurra'') is a
short-nosed bandicoot
The short-nosed bandicoots (genus ''Isoodon'') are members of the order (biology), order Peramelemorphia. These marsupials can be found across Australia, although their distribution can be patchy. Genetic evidence suggests that short-nosed bandic ...
found in northern
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
. It is the smallest of its genus.
The golden bandicoot is now a
threatened species
Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...
. It was once found throughout much of northwestern Australia, with even a patch on the
New South Wales
)
, nickname =
, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
/
South Australia
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...
border, but it is now restricted to the
Kimberley region of
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
, and to
Augustus
Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian, was the first Roman emperor; he reigned from 27 BC until his death in AD 14. He is known for being the founder of the Roman Pri ...
,
Barrow and Middle Islands off of Western Australia (''I. auratus barrowensis'') and
Marchinbar Island
Marchinbar Island is the largest island in the Wessel Islands in the Northern Territory of Australia in the Arafura Sea.
Location
It is separated from Rimbija Island, the most northeasterly of the Wessel Islands, by a narrow channel, which is ...
of
Northern Territory
The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...
. It is distinguished from the brown bandicoots by its golden colouring and much smaller size.
[
]
Taxonomy
Recent genetic evidence suggests that the not only is the golden bandicoot (''I. auratus'') closely related to the southern brown bandicoot
The southern brown bandicoot (''Isoodon obesulus'') is a short-nosed bandicoot, a type of marsupial, found mostly in southern Australia. It is also known as the quenda in South Western Australia (from the Noongar word '').
Taxonomy
George Shaw ...
. (''I. obesulus''), but that they may in fact be the same species.[River, South Alligator. "GOLDEN BANDICOOT Isoodon auratus." PDF from rm.nt.gov.au/ref> ]Mitochondrial
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is use ...
DNA evidence suggests that these two species ought to be grouped into one species with 3 distinct subspecies, ''I. obesulus obesulus'', ''I. o. peninsulae'', and ''I. o. fusciventer''. ''I. auratus'' would be included in the ''I. o. fusciventer'' subspecies, but these changes have yet to be accepted. These two appear to have been allopatric
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...
ever since the Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
, long before the arrival of Europeans. The golden bandicoot is also superficially similar to the relatively common northern brown bandicoot
The northern brown bandicoot (''Isoodon macrourus''), a marsupial species, is a bandicoot found only on the northern and eastern coasts of Australia and nearby islands, mainly Papua New Guinea. It is not, however, found far inland.
Description ...
(''I. macrourus''), but it can be distinguished by its smaller size, the shape of its hairs, and its more elongated head. In the current classification, three subspecies are recognised: ''I.a. auratus'', ''I.a. arnhemensis'', and ''I.a. barrowensis''.
Distribution
Range
The largest golden bandicoot population lives on Barrow Island because no cats or foxes have been introduced to the island, and other populations exist on Middle, Marchinbar, Augustus Islands. Small populations on mainland Australia are located in the Northern Territory and Western Australia. The golden bandicoot once lived all throughout Central Australia, but by 1992 it had been reduced to a small area in northwest Kimberly and Arnhem Land
Arnhem Land is a historical region of the Northern Territory of Australia, with the term still in use. It is located in the north-eastern corner of the territory and is around from the territory capital, Darwin. In 1623, Dutch East India Compan ...
. In 2000, it was assumed that the species was extinct on the mainland. Birds are the main threat to the species, and bandicoots must compete with rabbits for resources.
In the 1930s, the golden bandicoot was well spread throughout central Australia, but by 1983 the only populations on the mainland remained in the Prince Regent National Park
Prince Regent National Park, formerly the Prince Regent Nature Reserve, is a protected area in the Kimberley region of Western Australia. In 1978 the area was nominated as a UNESCO World Biosphere Reserve.
Land
The national park covers a to ...
in the Kimberley region. It occurs in stable numbers on Barrow, Middle and Augustus Islands, and by 1995 it was known to live in the Yampi Peninsula
Yampi Sound is a part of the Indian Ocean off the coast of north-western Australia, in the Kimberley region of Western Australia. It is located between King Sound and Collier Bay. It lies between the Yampi Peninsula and the islands of the Buc ...
in northern Kimberley and Marchinbar Island
Marchinbar Island is the largest island in the Wessel Islands in the Northern Territory of Australia in the Arafura Sea.
Location
It is separated from Rimbija Island, the most northeasterly of the Wessel Islands, by a narrow channel, which is ...
in the Northern Territory
The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...
. ''I.a. auratus'' occurs in the north-western Kimberley and the Augustus and Uwins Island
Uwins Island is located off the Kimberley coast of Western Australia.
The island encompasses an area of and is located in the Bonaparte Archipelago to the east of Hanover Bay and the west of Munster Water. Small area of mangroves, ''Avicenn ...
s, ''I.a. barrowensis'' occurs on Barrow and Middle Islands off the Pilbara
The Pilbara () is a large, dry, thinly populated region in the north of Western Australia. It is known for its Aboriginal peoples; its ancient landscapes; the red earth; and its vast mineral deposits, in particular iron ore. It is also a glo ...
coast, and ''I. a. arnhemensis'' has been recorded in Arnhem Land
Arnhem Land is a historical region of the Northern Territory of Australia, with the term still in use. It is located in the north-eastern corner of the territory and is around from the territory capital, Darwin. In 1623, Dutch East India Compan ...
.
It is present in the Charnley River–Artesian Range Wildlife Sanctuary in the Kimberley region of WA.
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
Gibson may refer to:
People
* Gibson (surname)
Businesses
* Gibson Brands, Inc., an American manufacturer of guitars, other musical instruments, and audio equipment
* Gibson Technology, and English automotive and motorsport company based
* Gi ...
, 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 12–35 hectares
The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is ab ...
, 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
It averages about 35 cm (or 14 in.) in length from head to tail and weighs between 260-655g (or 9–23 oz) with an average of 310 g (11 oz).[Survey guidelines for Australia's threatened mammals PDF from www.environment.gov.au › EPBC Act › Publications and resources] 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
Derby ( ) is a town in the Kimberley region of Western Australia. At the 2016 census, Derby had a population of 3,325 with 47.2% of Aboriginal and Torres Strait Islander descent. Along with Broome and Kununurra, it is one of only three towns i ...
.[Palmer, Carol, R. Taylor, and Andrew A. Burbidge. Recovery Plan for the Golden Bandicoot Isoodon Auratus and Golden-backed Tree-rat Mesembriomys Macrurus, 2004–2009. Department of Infrastructure, Planning and Environment, 2003.] As with most bandicoots, the golden bandicoot has a rather long, flat, pointy nose. It is an omnivore
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...
, consuming succulents
In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...
, insects, plant bulbs, and small reptiles. The golden bandicoot is nocturnal, foraging at night by digging small holes in the ground to find food.
The golden bandicoot is quite rat-like in appearance due to its small body, hunched-over posture, and relatively long tail. The hind limbs are large and muscular compared to the short forelimbs. Each forefoot has three toes with flat claws, used for digging holes when hunting for prey. And, unlike most marsupials, the golden bandicoot has fused toes on its hind feet, forming a comb they use for grooming. All bandicoots in the genus ''Isoodon'' have short noses and small, rounded ears, and thus can be distinguished from most other bandicoots, which have longer noses and larger ears. Female golden bandicoots have eight teats in the rear-opening pouch.
Physiology
Living in hot, semi-arid environments, the golden bandicoot is well adapted to keeping cool. Indeed, it is one of only two extant bandicoot species that are especially suited for arid environments, the other one being the bilby (''Macrotis lagotis'').[Dickman, Chris R. Overview of the impacts of feral cats on Australian native fauna. Canberra: Australian Nature Conservation Agency, 1996] Measurements in the laboratory show that the golden bandicoot has a low body temperature that is constantly changing; in this sense it is heterothermic
Heterothermy or heterothermia (from Greek ἕτερος ''heteros'' "other" and θέρμη ''thermē'' "heat") is a physiological term for animals that vary between self-regulating their body temperature, and allowing the surrounding environment to ...
. 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
Basal metabolic rate (BMR) is the rate of food energy, energy expenditure per unit time by endotherm, endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg b ...
, 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
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
. 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
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregna ...
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
The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is n ...
(''Rattus rattus'') reduced golden bandicoot numbers significantly in the 1990s, but the black rat was successfully eradicated from these islands in 1993.[Morris, K. D. "The eradication of the black rat (Rattus rattus) on Barrow and adjacent islands off the north-west coast of Western Australia." Turning the tide: the eradication of invasive species 27 (2002): 219–225.] Since then golden bandicoot numbers have increased five-fold. Additional competition comes from various rabbit species.
Predation
Large birds are the primary, natural predator of the golden bandicoot, but many predatory species have been introduced within its range. The European red fox (''Vulpes vulpes''), feral cats, and feral dogs all prey upon the golden bandicoot. When feral cats were introduced to Hermite Island, the golden bandicoot quickly became extinct just before 1912. On Marchinbar Island, hair samples from the golden bandicoot have been recovered in scat samples from feral dogs, and Aboriginal people
Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
have been known to hunt them as well.
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 efforts
A national recovery plan for the golden bandicoot and the golden-backed tree rat (''Mesembriomys macrurus'' ) was established in 2003 for a 5-year period between 2004–2009 with 3 management priorities summarised as follows:
# Form management arrangements between agencies, land managers, and land owners
# Form a multiple species recovery team to attack the issue of multiple species decline in northern Australia
# Monitor population trends
# Translocate golden bandicoots from Marchinbar Island to two other islands and follow up on said populations
# Identify the key components that affect critical weight range of tropical savannah mammals
# Develop educational materials to effectively communicate to stakeholders
# Inform and involve the community in recovery process
Both the Parks and Wildlife Service
The Department of Biodiversity, Conservation and Attractions (DBCA) is the Government of Western Australia, Western Australian government department responsible for managing lands and waters described in the ''Conservation and Land Management A ...
and the Gumurr Marthakal Rangers are involved in a collaborative program to monitor existing populations, search for new populations, and look for opportunities to translocate specimen.
In culture
The animal, known as Wan'kurra in the Yolngu language, features prominently in song-cycle
A song cycle (german: Liederkreis or Liederzyklus) is a group, or cycle, of individually complete songs designed to be performed in a sequence as a unit.Susan Youens, ''Grove online''
The songs are either for solo voice or an ensemble, or rare ...
s in the ceremonies
A ceremony (, ) is a unified ritualistic event with a purpose, usually consisting of a number of artistic components, performed on a special occasion.
The word may be of Etruscan origin, via the Latin '' caerimonia''.
Church and civil (secular) ...
of the Gumatj people of Arnhem Land
Arnhem Land is a historical region of the Northern Territory of Australia, with the term still in use. It is located in the north-eastern corner of the territory and is around from the territory capital, Darwin. In 1623, Dutch East India Compan ...
. It is a common motif in the work of artist Nancy Gaymala Yunupingu
Nancy Gaymala Yunupingu (1935–2005; also rendered Yunupiŋu) was a senior Yolngu artist and matriarch, who lived in Arnhem Land in the Northern Territory, Australia. She worked at the Buku-Larrnggay Mulka Centre in Yirrkala, where her wor ...
, often running through scrubland.
References
External links
Animal Info
IUCN Red List
Wildscreen Arkive
Australian Fauna
{{Taxonbar, from=Q194264
Peramelemorphs
Vulnerable fauna of Australia
Mammals of Western Australia
Extinct mammals of South Australia
Mammals of the Northern Territory
Marsupials of Australia
Mammals described in 1887