The Ord Victoria Plain, an interim Australian bioregion, is located 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 ...

and

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 ...

, comprising .IBRA Version 6.1
data The bioregion draws its name from the

Ord River The Ord River is a river in the Kimberley region of Western Australia. The river's catchment covers . The lower Ord River and the conjunction with Cambridge Gulf create the most northern estuarine environment in Western Australia. The Ord ...

and the Victoria River.

Location and description

This is an area of large plains of dry grassland lying between the

Tanami Desert The Tanami Desert is a desert in northern Australia, situated in the Northern Territory and Western Australia. It has a rocky terrain with small hills, and cacti. The Tanami was the Northern Territory's final frontier and was not fully explored b ...

to the south and the wetter, greener grassland to the north towards the coast. Sandstone outcrops rise from the grassland, the most famous of which is the Bungle Bungle Range in

Purnululu National Park The Purnululu National Park is a World Heritage Site in the East Kimberley region of Western Australia. The national park is located approximately south of Kununurra, with Halls Creek located to the south. Declared a World Heritage Site in 2 ...

. The grasslands have long been used for cattle grazing. The climate is wetter in the north (ave annual rainfall 1200mm), which receives some coastal

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...

al rain, and drier in the south (ave 600mm). The rainy season is between November and March and the whole area is almost completely dry for the rest of the year and the climate is hot with maximum temperatures between 25 °C and 35 °C year round.

Flora

The plain is largely covered with

Mitchell grass ''Astrebla'' is a small genus of xerophytic (adapted to survive in an environment with little liquid water) grasses found only in Australia. They are the dominant grass across much of the continent. They are commonly known as Mitchell grass aft ...

scattered with bloodwood ''

Eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as euca ...

'' / ''

Corymbia ''Corymbia'', commonly known as bloodwoods, is a genus of about one hundred species of tree that, along with ''Eucalyptus'', '' Angophora'' and several smaller groups, are referred to as eucalypts. Until 1990, corymbias were included in the gen ...

'' trees, native bauhinia ('' Bauhinia cunninghamii'') and large patches of lancewood acacia (''

Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...

shirleyi'') woodland. The sandstone outcrops have thinner cover of eucalyptus over hummock grass or heathland scattered with ''

Grevillea ''Grevillea'', commonly known as spider flowers, is a genus of about 360 species of evergreen flowering plants in the family Proteaceae. Plants in the genus ''Grevillea'' are shrubs, rarely trees, with the leaves arranged alternately along the b ...

'' and ''Acacia'' trees. Riverine ecosystems around permanent water courses consist of paperbark (''

Melaleuca ''Melaleuca'' () is a genus of nearly 300 species of plants in the myrtle family, Myrtaceae, commonly known as paperbarks, honey-myrtles or tea-trees (although the last name is also applied to species of '' Leptospermum''). They range in size ...

''), river redgum (''

'') and river pandanus (''

Pandanus ''Pandanus'' is a genus of monocots with some 750 accepted species. They are palm-like, dioecious trees and shrubs native to the Old World tropics and subtropics. The greatest number of species are found in Madagascar and Malaysia. Common names ...

'').

Fauna

There are few endemic species as these grasslands are typical of much of northern Australia at this latitude but the grasslands are nonetheless largely intact and rich in wildlife. Mammals include the large

eastern wallaroo The common wallaroo (''Osphranter robustus''), also known as the euro, hill wallaroo, or simply wallaroo, is a species of macropod. The word ''euro'' is particularly applied to one subspecies (''O. r. erubescens'').WE Poole and JC Merchant (198 ...

northern nail-tail wallaby The northern or sandy nail-tail wallaby (''Onychogalea unguifera'') is a species of macropod found across northern Australia on arid and sparsely wooded plains. The largest species of the genus '' Onychogalea'', it is a solitary and nocturnal h ...

(''Onychogalea unguifera''), and the

long-tailed planigale The long-tailed planigale (''Planigale ingrami''), also known as Ingram's planigale or the northern planigale, is the smallest of all marsupials, and one of the smallest of all mammals. It is rarely seen but is a quite common inhabitant of the bl ...

which is the smallest marsupial in the world. The lancewoods are home to the

spectacled hare-wallaby The spectacled hare-wallaby (''Lagorchestes conspicillatus'') is a species of macropod found in Australia and New Guinea. In Australia, a small sub-population is found on Barrow Island, while the mainland type is widespread, though in decline, ...

(''Lagorchestes conspicillatus''), while the Bungle Bungle has some unique plants and an endemic

Lerista ''Lerista'' is a diverse (~ 90 species) genus of skinks endemic to Australia, commonly known as sliders. The genus is especially notable for the variation in the amount of limb reduction. The variation ranges from short-bodied forms with la ...

skink Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Ski ...

lizard the '. Mammals that have become depleted or disappeared from these grasslands include the bilby (''Macrotis lagotis''),

northern quoll The northern quoll (''Dasyurus hallucatus''), also known as the northern native cat, the North Australian native cat or the satanellus is a carnivorous marsupial native to Australia. Taxonomy The northern quoll is a member of the family Das ...

(''Dasyurus hallucatus'') and

golden bandicoot The golden bandicoot (''Isoodon auratus''; Yolngu: ''Wan'kurra'') is a short-nosed bandicoot found in northern Australia. It is the smallest of its genus. The golden bandicoot is now a threatened species. It was once found throughout much o ...

(''Isoodon auratus''). Birds include

Australian bustard The Australian bustard (''Ardeotis australis'') is a large ground dwelling bird which is common in grassland, woodland and open agricultural country across northern Australia and southern New Guinea. It stands at about high, and its wingspan is ...

singing bushlark Horsfield's bush lark (''Mirafra javanica'') is a species of lark which inhabits grassland throughout most of Australia and much of Southeast Asia. It is named for American naturalist Thomas Horsfield. Taxonomy and systematics The Horsfield's b ...

, and

red-backed fairy-wren The red-backed fairywren (''Malurus melanocephalus'') is a species of passerine bird in the Australasian wren family, Maluridae. It is endemic to Australia and can be found near rivers and coastal areas along the northern and eastern coastlines ...

while there are important populations of

purple-crowned fairywren The purple-crowned fairywren (''Malurus coronatus'') is a species of bird in the Australasian wren family, Maluridae. It is the largest of the eleven species in the genus '' Malurus'' and is endemic to northern Australia. The species name is de ...

(''Malurus coronatus'') along the rivers especially the

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

. The eucalyptus trees are habitat for

lorikeet Loriini is a tribe of small to medium-sized arboreal parrots characterized by their specialized brush-tipped tongues for feeding on nectar of various blossoms and soft fruits, preferably berries. The species form a monophyletic group within the ...

friarbird The friarbirds, also called leatherheads, are about 15 species of relatively large honeyeaters in the genus ''Philemon''. Additionally, the single member of the genus ''Melitograis'' is called the white-streaked friarbird. Friarbirds are found ...

s, and

honeyeater The honeyeaters are a large and diverse family (biology), family, Meliphagidae, of small to medium-sized birds. The family includes the Epthianura, Australian chats, myzomelas, friarbirds, wattlebirds, Manorina, miners and melidectes. They are ...

Termite Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...

s are a source of food for many of these birds and animals. The wildlife of the grasslands is still being researched so for example a new species of

Ctenotus ''Ctenotus'' is a genus of skinks (family Scincidae). The genus belongs to a clade in the ''Sphenomorphus'' group which contains such genera as '' Anomalopus'' and the close relatives '' Eulamprus'' and '' Gnypetoscincus''. Lizards in the gen ...

has been discovered quite recently.

Threats and preservation

In general this is a large area of relatively unspoilt grassland used for grazing cattle. Some damage results from intensive cattle ranching leading to

overgrazing Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...

and disrupting the traditional Aboriginal

fire regime A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes th ...

s in which the grasslands are systematically burnt and allowed to regenerate. Woodlands next to rivers and other water sources were severely altered when ranching began, causing siltation along the

and destroying important habitat of the

white-browed robin The white-browed robin (''Poecilodryas superciliosa'') is a species of bird in the family Petroicidae. It is endemic to north-eastern Australia. Its natural habitats are forest, woodland and scrub, often near water. It formerly included the buf ...

(''Poecilodryas superciliosa'') and the purple-crowned fairywren. Habitats have also been damaged by introduced species of plants such as bellyache bush (''

Jatropha ''Jatropha'' is a genus of flowering plants in the spurge family, Euphorbiaceae. The name is derived from the Greek words ἰατρός (''iatros''), meaning "physician", and τροφή (''trophe''), meaning "nutrition", hence the common name ...

gossypifolia''), and

castor oil plant ''Ricinus communis'', the castor bean or castor oil plant, is a species of perennial flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, ''Ricinus'', and subtribe, Ricininae. The evolution of cas ...

(''Ricinus communis''). There are some protected areas, mainly other types of habitat rather than grazing land. Areas such as the caves of

Gregory National Park Judbarra National Park, formerly Gregory National Park, is a national park in the Northern Territory of Australia, 359 km south of Darwin. The park is the second largest national park in the Northern Territory, after Kakadu National Park, ...

are still being researched by botanists and zoologists.

Location and description

Flora

Fauna

Threats and preservation

See also

References

Further reading