Benger Swamp is a

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

located on the

Swan Coastal Plain The Swan Coastal Plain in Western Australia is the geographic feature which contains the Swan River as it travels west to the Indian Ocean. The coastal plain continues well beyond the boundaries of the Swan River and its tributaries, as a geol ...

, in south-west

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. The wetland is situated west of Benger, east of the coastal town of Binningup, south-west of Harvey, and south of

Perth Perth () is the list of Australian capital cities, capital city of Western Australia. It is the list of cities in Australia by population, fourth-most-populous city in Australia, with a population of over 2.3 million within Greater Perth . The ...

. Some 89% of the swamp is

protected Protection is any measure taken to guard something against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although ...

within the Benger Swamp Nature Reserve, while the remaining 11%, mainly in the northern part, is privately owned. It is a seasonally important site for

waterbird A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term ''water bird'' is especially applied to birds in freshwater ecosystems, although others make no distinction from seabi ...

s and is classified by

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding i ...

as an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

, with special regard to the conservation of

freckled duck The freckled duck (''Stictonetta naevosa)'' is a waterfowl species endemic to Australia. The freckled duck has also been referred to as the monkey duck or oatmeal duck. These birds are usually present in mainland Australia, but disperse to coas ...

s and

Australasian bittern The Australasian bittern (''Botaurus poiciloptilus''), or Matuku-hūrepo in Māori language, Māori, is a stocky, sizeable and elusive heron-like bird native to the Wetland, wetlands of Australia, New Zealand, and New Caledonia.Heather, B. D., & ...

s. Water levels in the swamp are controlled artificially and are managed both for

conservation and for

farming Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created ...

Description

The swamp lies in a depression on the Pinjarra Plain, part of the Swan Coastal Plain. The soils are

friable In materials science, friability ( ), the condition of being friable, describes the tendency of a solid substance to break into smaller pieces under stress or contact, especially by rubbing. The opposite of friable is indurate. Substances tha ...

, dark grey

loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–si ...

s overlying

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

s. To the west of the swamp are low ridges formed by

wind erosion Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit material ...

of the swamp surface when dried out in summer. Salinity measurements indicate that the swamp is a lens of fresh water overlying a saline

water table The water table is the upper surface of the phreatic zone or zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater, which may be fresh, saline, or brackish, depending on the loc ...

Flora

Some 20% of the swamp is covered by ''

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

'' trees and scrub, mainly on the northern and eastern edges. Of the four species there, ''

Melaleuca rhaphiophylla ''Melaleuca rhaphiophylla'', commonly known as swamp paperbark is a plant in the myrtle Family (biology), family, Myrtaceae and is Endemism, endemic to the Southwest Australia, south west of Western Australia. It has narrow, needle-like leaves an ...

'' (swamp paperbark) occurs as a dense low forest up to in height, while ''

Melaleuca viminea ''Melaleuca viminea'', commonly known as mohan, is a plant in the myrtle family Myrtaceae and is Endemism, endemic to the Southwest Australia, south-west of Western Australia. It is variable in size and form, from a densely branched small shrub ...

'', '' M. laterita'' and '' M. scabra'' are

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s. Half the swamp is covered by stands of the introduced bulrush ''

Typha orientalis ''Typha orientalis'', commonly known as bulrush, cumbungi, or raupō, is a perennial herbaceous plant in the genus ''Typha''. It is native to Australia, New Zealand, Malaysia, Indonesia, Japan, Korea, Mongolia, Myanmar, Philippines, China and th ...

''. ''

Baumea articulata ''Baumea articulata'', commonly known as jointed rush, is a sedge in the sedge family, Cyperaceae, that is native to Western Australia. The grass-like plant is rhizomatous and perennial, it typically grows to a height of . It blooms between Septe ...

'' (jointed rush) sedgeland covers about 1% of the swamp area. Flooded areas are dominated by couch grass (''

Cynodon dactylon ''Cynodon dactylon'', commonly known as Bermuda grass, also known as couch grass in Australia and New Zealand, is a grass found worldwide. It is native to Europe, Africa, Australia and much of Asia. It has been introduced to the Americas. Contra ...

'') and water couch (''

Paspalum distichum ''Paspalum distichum'' is a species of Poaceae, grass. Common names include knotgrass, water finger-grass, couch paspalum, eternity grass, gingergrass, and Thompson grass. Its native range is obscure because it has long been present on most conti ...

'').

Fauna

As well as freckled ducks and Australasian bitterns, other wetland bird species for which the swamp is an important site include the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

and

white-faced heron The white-faced heron (''Egretta novaehollandiae'') also known as the white-fronted heron, and incorrectly as the grey heron, or blue crane, is a common bird throughout most of Australasia, including New Guinea, the islands of Torres Strait, Indo ...

white White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wa ...

and

straw-necked ibis The straw-necked ibis (''Threskiornis spinicollis'') is a bird of the ibis and spoonbill family Threskiornithidae. It can be found throughout Australia, New Guinea, and parts of Indonesia. Adults have distinctive straw-like feathers on their neck ...

swamp harrier The swamp harrier (''Circus approximans''), also known as the Australasian marsh harrier or Australasian harrier, is a large, slim bird of prey widely distributed across Australasia. In New Zealand, it is also known by the Māori name . It arriv ...

purple swamphen The purple swamphen has been split into the following species: * Western swamphen, ''Porphyrio porphyrio'', southwest Europe and northwest Africa * African swamphen, ''Porphyrio madagascariensis'', sub-Saharan continental Africa and Madagascar * ...

hardhead The hardhead (''Aythya australis''), also known as the white-eyed duck, is the only true diving duck found in Australia. The common name "hardhead" has nothing to do with the density of the bird's skull, instead referring to the difficulty encou ...

spotless crake The spotless crake (''Zapornia tabuensis'') is a species of bird in the rail family, Rallidae. It is widely distributed species occurring from the Philippines, New Guinea, Australia, New Zealand across the southern Pacific Ocean to the Marquesas ...

wood sandpiper The wood sandpiper (''Tringa glareola'') is a small wader belonging to the sandpiper family Scolopacidae. A Eurasian species, it is the smallest of the shanks, a genus of mid-sized, long-legged waders that largely inhabit freshwater and wetland e ...

, Australian reed-warbler,

little grassbird The little grassbird (''Poodytes gramineus'') is a species of Old World warbler in the family Locustellidae. It is found in Australia and in West Papua, Indonesia. These sexually monomorphic birds are found in reed beds, rushes, lignum swamps an ...

and

blue-billed duck The blue-billed duck (''Oxyura australis'') is a small Australian stiff-tailed duck, with both the male and female growing to a length of 40 cm (16 in). The male has a slate-blue bill which changes to bright-blue during the breeding se ...

. Native mammals include

western grey kangaroo The western grey kangaroo (''Macropus fuliginosus''), also referred to as a western grey giant kangaroo, black-faced kangaroo, mallee kangaroo, sooty kangaroo and (when referring to the Kangaroo Island subspecies) Kangaroo Island grey kangaroo, i ...

s and

rakali The rakali (''Hydromys chrysogaster''), also known as the rabe, the "Australian otter" or water-rat, is an Australian native rodent first scientifically described in 1804. Adoption of the Ngarrindjeri name ''rakali'' is intended to foster a posit ...

Tiger snake The tiger snake (''Notechis scutatus'') is a large and highly venomous snake of southern Australia, including its coastal islands and Tasmania. These snakes are often observed and locally well known by their banding, black and yellow like a ti ...

s are common, as are introduced animals such as foxes, cats and rodents.

Threats

The stands of ''Typha'' dry out during the hot-dry summers of the region, providing fuel for

bushfires A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

which destroy the ''Melaleucas'' that provide moulting and breeding habitat for freckled ducks.

References

{{reflist, refs= {{cite journal , last1=Watkins , first1=D. , last2=P. , first2=Henderson , last3=J. , first3=Lane , last4=S. , first4=Moore , title=Benger Swamp Nature Reserve management plan 1987-1992 , url=http://researchrepository.murdoch.edu.au/id/eprint/21768 , website=researchrepository.murdoch.edu.au , publisher=Dept. of Conservation and Land Management , accessdate=1 July 2018 , date=1987 Wetlands of Western Australia Nature reserves in Western Australia Birdwatching sites in Australia Swan Coastal Plain Important Bird Areas of Western Australia

Description

Flora

Fauna

Threats

See also

References