Thomsons Lake Nature Reserve is a

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, funga, or features of geologic ...

around Thomsons Lake () in the

City of Cockburn The City of Cockburn ( ) is a local government area in the southern suburbs of the Western Australian capital city of Perth about south of Fremantle and about south of Perth's central business district. The City covers an area of and had a po ...

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 ...

, approximately south of the

central business district A central business district (CBD) is the Commerce, commercial and business center of a city. It contains commercial space and offices, and in larger cities will often be described as a financial district. Geographically, it often coincides wit ...

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 ...

, the state capital, and on the southern fringes of the Perth metropolitan area. It is in the suburb of Beeliar, south-west of

Jandakot Airport Jandakot Airport is a general aviation (GA) airport in Jandakot, Western Australia that opened in 1963, about south-southwest of Perth Airport. Originally built on unproductive farm lands, it is now among residential suburbs in the south of ...

. It is a still largely natural

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 ...

, with adjoining native vegetation, surrounded by land developed for housing and agriculture, that regularly supports large numbers of

shorebirds FIle:Vadare - Ystad-2021.jpg, 245px, A flock of Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflats in order to foraging, forage for food c ...

and other

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 ...

Protection

The lake is listed on the

Register of the National Estate The Register of the National Estate was a heritage register that listed natural and cultural heritage places in Australia that was closed in 2007. Phasing out began in 2003, when the Australian National Heritage List and the Commonwealth Heri ...

. With the similar Forrestdale Lake to the east, it forms the Forrestdale and Thomsons Lakes Ramsar Site, designated under the

Ramsar Convention The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar site, Ramsar sites (wetlands). It is also known as the Convention on We ...

on 7 June 1990 and recognising it as a wetland of international importance. The lake and its surrounds are registered as Nature Reserve 15556, vested in the Conservation Commission of Western Australia and managed by the Department of Conservation and Land Management. The reserve is also part of the Beeliar Regional Park.

Description

Thomsons Lake Nature Reserve, including the lake and adjacent woodland, has an area of . The lake is a shallow, brackish, seasonal lake with a large area of open water when full. It has extensive fringing sedgeland typical of 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 ...

, and is a major breeding site, migration stop-over and semi-permanent drought refuge area for

s. It usually dries out during the summer, though occasionally retaining some water through the year. It is fenced to exclude feral predators. It is mainly used for

birdwatching Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device such as binoculars or a telescop ...

, nature walks, and general recreation by surrounding residents. Within the reserve there is a network of fire-breaks and management access tracks used for

bushwalking A hike is a long, vigorous walking, walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century. Long hikes as part of a religious pilgrimage have existed for a much longer tim ...

, while

horse riding Equestrianism (from Latin , , , 'horseman', 'horse'), commonly known as horse riding ( Commonwealth English) or horseback riding (American English), includes the disciplines of riding, driving, and vaulting. This broad description includes the ...

is only allowed on a perimeter track outside the vermin-proof fence.

Geology and hydrology

The lake occupies a depression between two dune systems – the Bassendean System to the east, and the younger Spearwood System to the west. These dunes are the result of the accumulation and subsequent distribution of beach sands along successive shorelines from a series of marine incursions combined with the prevailing westerly winds. Palaeobotanical studies show that the lake sediments are 30–40,000 years old, making them the oldest found in Western Australia. The lake lies on the Jandakot Groundwater Mound - a region of elevated groundwater beneath the Swan Coastal Plain.

Flora and fauna

Water milfoil ''Myriophyllum'' (water milfoil) is a genus of about 69 species of freshwater aquatic plants, with a cosmopolitan distribution. The centre of diversity for ''Myriophyllum'' is Australia with 43 recognized species (37 endemic). These submersed aq ...

grows abundantly in the lake. The fringing zone around the edge is characterised by the introduced

bulrush Bulrush is a vernacular name for several large wetland graminoid, grass-like plants *Sedge family (Cyperaceae): **''Cyperus'' **''Scirpus'' **''Blysmus'' **''Bolboschoenus'' **''Scirpoides'' **''Isolepis'' **''Schoenoplectus'' **''Trichophorum'' ...

'' Typha orientalis'' and the

sedge The Cyperaceae () are a family of graminoid (grass-like), monocotyledonous flowering plants known as wikt:sedge, sedges. The family (biology), family is large; botanists have species description, described some 5,500 known species in about 90 ...

'' Baumea articulata''. When water levels drop, the club-rush '' Bolboschoenus caldwellii'' becomes established on the exposed

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal ...

s within the fringing zone, while behind it is a belt of '' Baumea juncea'' and ''Baumea articulata'' with emergent native broom and shrubs of orange wattle. Behind these is a belt of the trees flooded gum and stout paperbark, and the shrub

grey stinkwood ''Jacksonia furcellata'', commonly known as grey stinkwood, is a species of flowering plant in the family Fabaceae and is endemic to the Southwest Australia, south-west of Western Australia. It is a prostrate to low-lying, or weeping erect shru ...

. On higher ground these are replaced by open forest or woodland dominated by

jarrah ''Eucalyptus marginata'', commonly known as jarrah, in Noongar language and historically as Swan River mahogany, is a plant in the myrtle family, Myrtaceae and is endemic to the south-west of Western Australia. It is a tree with rough, fibro ...

, firewood banksia and candlestick banksia. Some 476

vascular plant Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignin, lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified Ti ...

s (including 133 introduced weeds) from 81

families Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...

have been recorded in the reserve. The lake is one of the last refuges for the

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

Australasian bittern on the Swan Coastal Plain; it is the only wetland in the Perth metropolitan area where the

marsh harrier The marsh harriers are bird of prey, birds of prey of the harrier (bird), harrier subfamily. They are medium-sized Bird of prey, raptors and the largest and broadest-winged harriers. Most of them are associated with marshland and dense reedbeds. ...

still breeds, and one of few known breeding sites for

Baillon's crake Baillon's crake (''Zapornia pusilla''), also known as the marsh crake, is a small waterbird of the family Rallidae. Distribution Their breeding habitat is sedge beds in Europe, mainly in the east, and across the Palearctic. They used to breed in ...

. It regularly supports more than 1% of the national population of four shorebirds:

red-capped plover The red-capped plover (''Anarhynchus ruficapillus''), also known as the red-capped dotterel, is a small species of plover. It breeds in Australia. This species is closely related to (and sometimes considered conspecific with) the Kentish plover, ...

(with up to 1,000 counted), black-winged stilt (3,000), red-necked avocet (3,000), and

curlew sandpiper The curlew sandpiper (''Calidris ferruginea'') is a small wader that breeds on the tundra of Arctic Siberia. It is strongly bird migration, migratory, wintering mainly in Africa, but also in south and southeast Asia and in Australia and New Zeal ...

(2,500). The lake often holds more than 10,000 waterbirds, with the highest number counted over 20,000. The most numerous are

Australian shelduck The Australian shelduck (''Tadorna tadornoides''), also known as the chestnut-breasted shelduck or mountain duck, is a shelduck, a group of large goose-like ducks part of the bird family Anatidae. The genus name ''Tadorna'' comes from Celtic ...

(with up to 1,600 counted),

Pacific black duck The Pacific black duck (''Anas superciliosa''), commonly known as the PBD, is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the no ...

(4,500), grey teal (6,000),

Australasian shoveler The Australasian shoveler (''Spatula rhynchotis'') is a species of dabbling duck in the genus ''Spatula''. It ranges from . It lives in heavily vegetated swamps. In Australia it is protected under the National Parks and Wildlife Act 1974. ...

(2,000), and

Eurasian coot The Eurasian coot (''Fulica atra''), also known as the common coot, or Australian coot, is a member of the rail and crake bird family, the Rallidae. It is found in Europe, Asia, Australia, New Zealand and parts of North Africa. It has a slaty-bla ...

(7,000). The reserve contains a population of

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. The long-necked tortoise is present. Six

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

species and up to 80 aquatic

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

taxa have been recorded.

References

{{reflist Lakes of Perth, Western Australia Nature reserves in Western Australia Ramsar sites in Australia Birdwatching sites in Australia Beeliar Regional Park

Protection

Description

Geology and hydrology

Flora and fauna

See also

References