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81-585: The Australasian bittern ( Botaurus poiciloptilus ), or Matuku-hūrepo in Māori , is a stocky, sizeable and elusive heron-like bird native to the wetlands of Australia , New Zealand , and New Caledonia . It belongs to the bittern subfamily of the heron family Ardeidae . The Australasian bittern is best known for its cryptic plumage and behaviours, which allows it to blend into the rushes and reeds of its wetland habitats, making it particularly difficult to spot. Despite being rarely seen, Australasian bittern males have

162-711: A sink or a source of carbon, depending on the specific wetland. If they function as a carbon sink, they can help with climate change mitigation . However, wetlands can also be a significant source of methane emissions due to anaerobic decomposition of soaked detritus , and some are also emitters of nitrous oxide . Humans are disturbing and damaging wetlands in many ways, including oil and gas extraction , building infrastructure, overgrazing of livestock , overfishing , alteration of wetlands including dredging and draining, nutrient pollution , and water pollution . Wetlands are more threatened by environmental degradation than any other ecosystem on Earth, according to

243-517: A challenging species to detect and study. This species demonstrates all four types of cryptic features found in members of the Botaurus genus: visual crypsis, behavioural crypsis, spatial crypsis (due to its habitat selection of dense vegetation), and temporal crypsis. When disturbed by humans or predators, bitterns often freeze in a rigid pose. This behaviour, combined with their beige, striated and mottled plumage, makes them difficult to detect among

324-579: A distinct "booming" call that can carry long distances. Physically, the Australasian bittern stands around 66-76 cm tall with a wingspan of around a metre long. Its streaky, beige, mottled plumage allows it to camouflage itself among the reeds and rushes of its habitat to avoid predators and hunt for prey, undetected. The species primarily feeds on fish, amphibians , and invertebrates , which it hunts by quietly stalking through shallow waters or remaining "frozen" before ambushing its prey. Historically,

405-402: A frequency and duration to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally included swamps, marshes, bogs, and similar areas.' For each of these definitions and others, regardless of the purpose, hydrology is emphasized (shallow waters, water-logged soils). The soil characteristics and

486-685: A likely historical and cultural association with the species. Ecologically, the Australasian bittern is a crucial indicator of wetland health, as its survival depends on diverse, high-quality habitats. Wetlands, in turn, provide essential ecosystem services, such as water purification, fish nurseries, and recreational or commercial fishing opportunities. Increasing awareness of the Australasian bitterns' presence in agricultural environments like rice fields in Australia means that, given how threatened these birds are, future land development proposals will need to consider these birds and their impact on them. For

567-1259: A polar climate, wetland temperatures can be as low as −50 °C (−58 °F). Peatlands in arctic and subarctic regions insulate the permafrost , thus delaying or preventing its thawing during summer, as well as inducing its formation. The amount of precipitation a wetland receives varies widely according to its area. Wetlands in Wales , Scotland , and western Ireland typically receive about 1,500 mm (59 in) per year. In some places in Southeast Asia , where heavy rains occur, they can receive up to 10,000 mm (390 in). In some drier regions, wetlands exist where as little as 180 mm (7.1 in) precipitation occurs each year. Temporal variation: Surface flow may occur in some segments, with subsurface flow in other segments. Wetlands vary widely due to local and regional differences in topography , hydrology , vegetation , and other factors, including human involvement. Other important factors include fertility, natural disturbance, competition, herbivory , burial and salinity. When peat accumulates, bogs and fens arise. The most important factor producing wetlands

648-540: A portion of the overall water cycle, which also includes atmospheric water (precipitation) and groundwater . Many wetlands are directly linked to groundwater and they can be a crucial regulator of both the quantity and quality of water found below the ground. Wetlands that have permeable substrates like limestone or occur in areas with highly variable and fluctuating water tables have especially important roles in groundwater replenishment or water recharge. Substrates that are porous allow water to filter down through

729-734: A prey, they slowly and steadily “stalk” them until they are proximate enough that they can stab or grab their prey with minimal commotion or sound. This is why the quality and depth of water in their habitat are important for the Australasian bittern's ability to detect and access their prey. When hunting for frogs, they have also been observed to manipulate and toss the prey before consuming them slowly. Socially, Australasian bitterns are mainly solitary, with occasional sightings of pairs together. However, there are significant gaps in current understandings of their social behaviours and daily activity patterns. The Australasian bittern holds cultural, environmental, and economic importance. This species

810-404: A protective barrier to coastal shoreline. Mangroves stabilize the coastal zone from the interior and will migrate with the shoreline to remain adjacent to the boundary of the water. The main conservation benefit these systems have against storms and storm surges is the ability to reduce the speed and height of waves and floodwaters. Whangamarino Wetland The Whangamarino Wetland in

891-545: A rich and representative variety of wetland ecosystems (peat bog, swamp, mesotrophic lags, open water and river systems); one of the features that lent support to its designation under the Ramsar Convention. 239 species of wetland plants are found in the Whangamarino, 60 percent of which are indigenous . A number of these are uncommon or extremely rare, including the water milfoil Myriophyllum robustum ,

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972-533: A seasonal hydrological cycle. The single-track North Island Main Trunk railway line crosses the wetland, and it has been proposed that two million tonnes of spoil from the Auckland City Rail Link could be used to double-track the busy section of line which is a bottleneck on the section between Auckland (Papakura) and Hamilton. Sometimes known as 'nature's benefits’, ecosystem services are

1053-564: A sharp decline, and current estimates suggest that there are now less than 1,000 individuals, prompting its classification as Endangered under the Australian Environment Protection and Biodiversity Conservation Act 1999 . Today, over half of Australia's Australasian bittern population is thought to reside in New South Wales (NSW). Recent research indicates that during the breeding season, rice fields in

1134-522: A short track to Te Teoteo's pā and the Whangamarino Redoubt at the confluence of the Whangamarino and Waikato Rivers. Here, visitors can stand at the site where two forty-pound Armstrong guns fired on Māori entrenchments at Meremere pā and also obtain a good scenic view looking south over the northern part of the wetland. Whangamarino Wetland has been subject to intensive biodiversity management, research, and community awareness campaigns by

1215-415: A stalking method, primarily at the edges of ponds. They first remain motionless for up to ten minutes while swiveling their eyes to survey their surroundings before opportunistically targeting their prey. This eye-swiveling technique helps them see beneath their bills while keeping their beaks high in the air to maintain a frozen surveillance posture and blend into their environment. Once they have locked on to

1296-574: A stealthy and cautious motion as they move along the edges of their dense habitats, looking for food. While they are frequently found foraging at night, they have also been observed foraging during the day, especially in winter. This apparent flexibility in their foraging behaviours complicates current understandings of their daily habits. Furthermore, their foraging patterns appear to vary based on nearby anthropogenic activities or changes, such as duck hunting seasons and fluctuations in water levels . When actively hunting, Australasian bitterns typically employ

1377-422: A strong influence on wetland water chemistry, particularly in coastal wetlands and in arid and semiarid regions with large precipitation deficits. Natural salinity is regulated by interactions between ground and surface water, which may be influenced by human activity. Carbon is the major nutrient cycled within wetlands. Most nutrients, such as sulfur , phosphorus , carbon , and nitrogen are found within

1458-410: A unique kind of wetland where lush plant growth and slow decay of dead plants (under anoxic conditions) results in organic peat accumulating; bogs, fens, and mires are different names for peatlands. Variations of names for wetland systems: Some wetlands have localized names unique to a region such as the prairie potholes of North America's northern plain, pocosins , Carolina bays and baygalls of

1539-515: A wetland is "an ecosystem that arises when inundation by water produces soils dominated by anaerobic and aerobic processes, which, in turn, forces the biota, particularly rooted plants, to adapt to flooding". Sometimes a precise legal definition of a wetland is required. The definition used for regulation by the United States government is: 'The term "wetlands" means those areas that are inundated or saturated by surface or ground water at

1620-422: A wetland system includes its plants ( flora ) and animals ( fauna ) and microbes (bacteria, fungi). The most important factor is the wetland's duration of flooding. Other important factors include fertility and salinity of the water or soils. The chemistry of water flowing into wetlands depends on the source of water, the geological material that it flows through and the nutrients discharged from organic matter in

1701-403: A wetland) affects hydro-periods (temporal fluctuations in water levels) by controlling the water balance and water storage within a wetland. Landscape characteristics control wetland hydrology and water chemistry. The O 2 and CO 2 concentrations of water depend upon temperature , atmospheric pressure and mixing with the air (from winds or water flows). Water chemistry within wetlands

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1782-558: A whole. To replace these wetland ecosystem services , enormous amounts of money would need to be spent on water purification plants, dams, levees, and other hard infrastructure, and many of the services are impossible to replace. Floodplains and closed-depression wetlands can provide the functions of storage reservoirs and flood protection. The wetland system of floodplains is formed from major rivers downstream from their headwaters . "The floodplains of major rivers act as natural storage reservoirs, enabling excess water to spread out over

1863-594: A wide area, which reduces its depth and speed. Wetlands close to the headwaters of streams and rivers can slow down rainwater runoff and spring snowmelt so that it does not run straight off the land into water courses. This can help prevent sudden, damaging floods downstream." Notable river systems that produce wide floodplains include the Nile River , the Niger river inland delta, the Zambezi River flood plain,

1944-575: Is also home to longfin and shortfin eel/tuna and other galaxiid species. Introduced invasive fish species are also present in Whangamarino Wetland; koi carp ( Cyprinus carpio ) and brown bullhead catfish ( Ameiurus nebulosus ) are a particular problem as their aggressive feeding behaviour stirs up bottom sediments, affecting bank stabilisation and aquatic plant life. A study of koi carp otoliths undertaken by University of Waikato MSc student Jennifer Blair found that Lake Waikare and

2025-440: Is determined by the pH , salinity , nutrients, conductivity , soil composition, hardness , and the sources of water. Water chemistry varies across landscapes and climatic regions. Wetlands are generally minerotrophic (waters contain dissolved materials from soils) with the exception of ombrotrophic bogs that are fed only by water from precipitation. Because bogs receive most of their water from precipitation and humidity from

2106-633: Is either freshwater , brackish or saltwater . The main types of wetland are defined based on the dominant plants and the source of the water. For example, marshes are wetlands dominated by emergent herbaceous vegetation such as reeds , cattails and sedges . Swamps are dominated by woody vegetation such as trees and shrubs (although reed swamps in Europe are dominated by reeds, not trees). Mangrove forest are wetlands with mangroves , halophytic woody plants that have evolved to tolerate salty water . Examples of wetlands classified by

2187-412: Is hydrology, or flooding . The duration of flooding or prolonged soil saturation by groundwater determines whether the resulting wetland has aquatic, marsh or swamp vegetation . Other important factors include soil fertility, natural disturbance, competition, herbivory , burial, and salinity. When peat from dead plants accumulates, bogs and fens develop. Wetland hydrology is associated with

2268-430: Is known that the Australasian bittern shows a strong preference for densely vegetated habitats rich in rushes , reeds , and sedges , thriving in both temperate and subtropical climates. These birds travel seasonally by flight for long distances (up to 600 km) to exploit coastal wetlands . Australia's population was estimated at 2,500 mature individuals before around 2010. However, a severe drought around then led to

2349-574: Is relevant and acknowledged in New Zealand in Te Ao Māori , referenced in historical Māori legends, metaphors, and place names. Historically, the bittern's feathers were also used for ceremonial decoration, and the bird served as a food source for tangata whenua . While cultural connections with indigenous Australians are less documented, the bittern is known as "boordenitj" in Noongar , hinting to

2430-451: Is the only place in the world where both crocodiles and alligators coexist. The saltwater crocodile inhabits estuaries and mangroves. Snapping turtles also inhabit wetlands. Birds , particularly waterfowl and waders use wetlands extensively. Mammals of wetlands include numerous small and medium-sized species such as voles , bats , muskrats and platypus in addition to large herbivorous and apex predator species such as

2511-545: Is usually saturated with water". More precisely, wetlands are areas where "water covers the soil , or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season". A patch of land that develops pools of water after a rain storm would not necessarily be considered a "wetland", even though the land is wet. Wetlands have unique characteristics: they are generally distinguished from other water bodies or landforms based on their water level and on

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2592-505: The Millennium Ecosystem Assessment from 2005. Methods exist for assessing wetland ecological health . These methods have contributed to wetland conservation by raising public awareness of the functions that wetlands can provide. Since 1971, work under an international treaty seeks to identify and protect " wetlands of international importance ." A simplified definition of wetland is "an area of land that

2673-688: The Pantanal in South America, and the Sundarbans in the Ganges - Brahmaputra delta. Wetlands contribute many ecosystem services that benefit people. These include for example water purification , stabilization of shorelines, storm protection and flood control . In addition, wetlands also process and condense carbon (in processes called carbon fixation and sequestration ), and other nutrients and water pollutants . Wetlands can act as

2754-594: The Riverina region of NSW hold between 500 - 1,000 bittern individuals, the largest known breeding population for this species. Before this research, the significance of agricultural wetlands, especially rice fields, as vital habitats for this cryptic species, had been overlooked. In New Zealand, earlier population estimates of the Australasian bittern are likely inflated, as the degradation of their habitats and fewer recorded booming males at essential wetland sites, such as Whangamarino (the most significant NZ habitat for

2835-661: The Waikato District is the second largest wetland complex of the North Island of New Zealand . Encompassing a total area of more than 7200 hectares, the Department of Conservation Te Papa Atawhai manages 5,923 hectares of peat bog , swamp , mesotrophic lags, open water and river systems listed as a wetland of international importance under the Ramsar Convention . Fish and Game New Zealand are

2916-444: The atmosphere , their water usually has low mineral ionic composition. In contrast, wetlands fed by groundwater or tides have a higher concentration of dissolved nutrients and minerals. Fen peatlands receive water both from precipitation and ground water in varying amounts so their water chemistry ranges from acidic with low levels of dissolved minerals to alkaline with high accumulation of calcium and magnesium . Salinity has

2997-576: The beavers , coypu , swamp rabbit , Florida panther , jaguar , and moose . Wetlands attract many mammals due to abundant seeds, berries, and other vegetation as food for herbivores, as well as abundant populations of invertebrates, small reptiles and amphibians as prey for predators. Invertebrates of wetlands include aquatic insects such as dragonflies , aquatic bugs and beetles , midges, mosquitos , crustaceans such as crabs, crayfish, shrimps, microcrustaceans, mollusks like clams, mussels, snails and worms. Invertebrates comprise more than half of

3078-519: The clubmoss Lycopodium serpentinum , and the critically endangered swamp helmet orchid Corybas carsei , now found nowhere else in the world. Baumea spp., mānuka ( Leptospermum scoparium ) and wire rush ( Empodisma minus ) are the dominant vegetation of the peat bogs, while greater species diversity is found in the mineralised swamp zones, including introduced species such as grey willow ( Salix cinerea ) and crack willow ( Salix × fragilis ). Mosses and lichens are also well represented in

3159-570: The Australasian bittern remains unresolved, and debated among ornithologists. Its order, in particular, is ambiguous amongst the literature with some sources placing it in Ciconiiformes and others in Pelecaniformes . The Australasian bittern is a relatively large, stocky bird with noticeable size dimorphism between the sexes. Males can weigh up to 1.4 kg, while females are smaller, typically weighing around 0.9 kg. Beyond size,

3240-764: The Australasian bittern was described in the early 19th century and has since been of significant interest due to its cryptic nature. The species is classified as Vulnerable on the IUCN Red List , and continues to experience population declines resulting from habitat reduction and disturbance from wetland drainage, climate change and agricultural expansion . Conservation efforts are therefore becoming increasingly necessary for its survival. Researchers continue to attempt to understand this birds' daily patterns, ecology, and breeding behaviour to improve current conservation strategies, although their cryptic nature makes this particularly difficult. The taxonomic classification of

3321-582: The Department of Conservation as part of the Arawai Kākāriki wetland restoration programme. Conservation measures taken to maintain or improve biodiversity include controlling weeds, particularly grey willow, aquatic grasses, yellow flag iris, alligator weed and gorse, and mammalian pests, including mustelids, rodents, cats and possum. The Whangamarino weir was repaired in 2010 and is now operating as it should to help maintain minimum summer water levels in

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3402-482: The Department of Conservation to improve wetland habitat and control predators around popular hunting sites. Whangamarino is located within the rohe (area) of the Waikato-Tainui iwi (tribe) and is considered a taonga (treasure) by local hapū . Early Māori utilised the wetland as a source of eel/tuna and birds for food, and flax/harakeke ( Phormium tenax ) for traditional cultural purposes. The rivers of

3483-639: The Okavango River inland delta, the Kafue River flood plain, the Lake Bangweulu flood plain (Africa), Mississippi River (US), Amazon River (South America), Yangtze River (China), Danube River (Central Europe) and Murray-Darling River (Australia). Groundwater replenishment can be achieved for example by marsh , swamp , and subterranean karst and cave hydrological systems. The surface water visibly seen in wetlands only represents

3564-556: The Pungarehu Stream appear to be a source of recruits, with koi carp moving from these areas into the Waikato River and Lake Waahi. Hydrology is a driving component of wetlands, with many plants and animals uniquely adapted to the seasonal wet/dry cycle. Whangamarino Wetland is fed by a catchment area of approximately 48,900 hectares. During the 1960s the hydrology of the Whangamarino was significantly impacted by

3645-464: The Riverina's rice fields, bittern conservation is already considered alongside rice-farming policies, especially around water allocation. Despite its significance to humans, the Australasian bittern faces severe population declines, driven particularly by the loss of wetlands due to agricultural expansion, more frequent dry seasons, altered land use and climate change. In Australia and New Zealand,

3726-522: The Southeastern US, mallines of Argentina, Mediterranean seasonal ponds of Europe and California, turloughs of Ireland, billabongs of Australia, among many others. Wetlands are found throughout the world in different climates. Temperatures vary greatly depending on the location of the wetland. Many of the world's wetlands are in the temperate zones , midway between the North or South Poles and

3807-502: The US, the best known classifications are the Cowardin classification system and the hydrogeomorphic (HGM) classification system. The Cowardin system includes five main types of wetlands: marine (ocean-associated), estuarine (mixed ocean- and river-associated), riverine (within river channels), lacustrine (lake-associated) and palustrine (inland nontidal habitats). Peatlands are

3888-610: The United States' commercial fish and shellfish stocks depend solely on estuaries to survive. Amphibians such as frogs and salamanders need both terrestrial and aquatic habitats in which to reproduce and feed. Because amphibians often inhabit depressional wetlands like prairie potholes and Carolina bays, the connectivity among these isolated wetlands is an important control of regional populations. While tadpoles feed on algae, adult frogs forage on insects. Frogs are sometimes used as an indicator of ecosystem health because their thin skin permits absorption of nutrients and toxins from

3969-527: The Waikato Region $ 5.2 million (in 2007 dollars) by limiting damage to surrounding farmland during times of peak flood events. Farmers are a particular benefactor of wetland ecosystem services. On good quality wetland margins, damp soils and dense pockets of native rushes and sedges are effective in: Whangamarino is a popular duck hunting location and recreational fishers targeting koi carp, rudd, catfish, goldfish, eel and mullet are regularly seen in

4050-407: The Whangamarino is visited by other unusual birds such as royal spoonbill/kōtuku-ngutupapa ( Platalea regia ) and Japanese snipe ( Gallinago hardwickii ), which helps keeps amateur ornithologists interested in the site. The wetland provides habitat for a diverse range of native freshwater fish, including a significant population of the threatened black mudfish/waikaka ( Neochanna diversus ). It

4131-622: The Whangamarino until it is released back into the Waikato River via flood gates on the Whangamarino River . In 1994 the construction of a rock rubble weir on the Whangamarino River was commissioned by the Department of Conservation and the Auckland/Waikato Fish and Game Council. The weir maintains minimum summer water levels in approximately 1,400 hectares of the mineralised wetland and helps recreate

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4212-718: The benefits (usually to humans) provided by natural ecosystems. They include provisions such as clean drinking water, supporting processes like the decomposition of wastes, and cultural benefits such as spiritual or recreational opportunities. Wetlands provide an astonishing array of ecosystem services for the local community. These include mitigating the effects of flood and drought, replenishing groundwater , helping filter sediment and nutrients and purify water, providing reservoirs of biodiversity and wetland resources, providing for cultural values, recreation and tourism, and climate change mitigation and adaptation. The Lower Waikato-Waipa Flood Protection Scheme has been estimated to save

4293-451: The bird. In contrast, females are generally quieter but may occasionally produce "bubbling" sounds or louder calls when alarmed. Females take on the primary responsibilities of incubating the eggs in their nests and later feeding the hatchlings. Information and data on nesting and reproductive biology of Australasian bitterns is limited. The Australasian bittern exhibits various complex and cryptic behaviours , underscoring why it has been

4374-633: The bittern's range now mainly limited to coastal and lowland wetlands of the North Island . Conservation efforts have focused on habitat protection and wetland restoration. However, the ongoing challenges of water allocation, habitat destruction, and predation by introduced mammals continue to pose significant risks to the species' survival. New Caledonia's population is understudied, with fewer than 50 individuals suspected and limited sightings since 2016. Wetland Wetlands exist on every continent , except Antarctica . The water in wetlands

4455-758: The clearance and degradation of wetlands has been a significant historical and ongoing threat to these birds. The species is listed as Endangered under Australia's EPBC Act and as Nationally Critical in New Zealand, with fewer than 2,499 mature individuals globally, and trends suggesting further declines. In Australia, especially the Murray-Darling Basin , wetlands have been significantly diminished. While rice crops provide some novel breeding habitat, reducing rice farming, driven by high water prices and shifting crop preferences (such as cotton ), further threatens to reduce suitable bittern habitats. In New Zealand, declines have been most pronounced after 1970, with

4536-473: The direction of the Te Onetea Stream was reversed to transport water from the Waikato River into Lake Waikare during high river flows, while the level of Lake Waikare was lowered by one metre. The lake is kept to a strict fluctuation regime of approximately 0.3 metres and flood gates control the movement of water into the Whangamarino Wetland via the artificial Pungarehu Canal. Water is then stored in

4617-634: The equator. In these zones, summers are warm and winters are cold, but temperatures are not extreme. In subtropical zone wetlands, such as along the Gulf of Mexico , average temperatures might be 11 °C (52 °F). Wetlands in the tropics are subjected to much higher temperatures for a large portion of the year. Temperatures for wetlands on the Arabian Peninsula can exceed 50 °C (122 °F) and these habitats would therefore be subject to rapid evaporation. In northeastern Siberia , which has

4698-504: The following areas: According to the Ramsar Convention: The economic worth of the ecosystem services provided to society by intact, naturally functioning wetlands is frequently much greater than the perceived benefits of converting them to 'more valuable' intensive land use – particularly as the profits from unsustainable use often go to relatively few individuals or corporations, rather than being shared by society as

4779-562: The implementation of the Lower Waikato-Waipa Flood Control Scheme managed by Waikato Regional Council, and has also been impacted by the extraction of sand and hydro-power generation on the Waikato River . The flood control scheme is intended to replicate the natural water storage function of Lake Waikare and Whangamarino Wetland in a highly manipulated and more controlled way. To do this,

4860-468: The interface between truly terrestrial ecosystems and aquatic systems, making them inherently different from each other, yet highly dependent on both." In environmental decision-making, there are subsets of definitions that are agreed upon to make regulatory and policy decisions. Under the Ramsar international wetland conservation treaty , wetlands are defined as follows: An ecological definition of

4941-569: The introduction of non-native species, and other anthropogenic-driven environmental changes. Australasian bitterns share several reproductive traits with other species in the Botaurus genus, and has a breeding season that spans from June to February. A key characteristic of Australasian bitterns is the male's distinctive "booming" vocalisations, which is though to attract mates and assist in defending their territories against other bittern males. These booms can be heard up to 4 kilometres away from

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5022-462: The known animal species in wetlands, and are considered the primary food web link between plants and higher animals (such as fish and birds). Depending on a wetland's geographic and topographic location, the functions it performs can support multiple ecosystem services , values, or benefits. United Nations Millennium Ecosystem Assessment and Ramsar Convention described wetlands as a whole to be of biosphere significance and societal importance in

5103-837: The plants and animals controlled by the wetland hydrology are often additional components of the definitions. Wetlands can be tidal (inundated by tides) or non-tidal. The water in wetlands is either freshwater , brackish , saline , or alkaline . There are four main kinds of wetlands – marsh , swamp , bog , and fen (bogs and fens being types of peatlands or mires ). Some experts also recognize wet meadows and aquatic ecosystems as additional wetland types. Sub-types include mangrove forests , carrs , pocosins , floodplains , peatlands, vernal pools , sinks , and many others. The following three groups are used within Australia to classify wetland by type: Marine and coastal zone wetlands, inland wetlands and human-made wetlands. In

5184-486: The second largest landowner, managing 748 hectares of the wetland primarily as gamebird hunting habitat. The site is also one of three of New Zealand’s foremost wetlands included in the Arawai Kākāriki wetland restoration programme, which aims to “enhance the ecological restoration of three of New Zealand’s foremost wetland/freshwater sites, making use of strong community involvement and promoting research into wetland restoration techniques”. Whangamarino Wetland consists of

5265-429: The soil and underlying rock into aquifers which are the source of much of the world's drinking water . Wetlands can also act as recharge areas when the surrounding water table is low and as a discharge zone when it is high. Mangroves , coral reefs , salt marsh can help with shoreline stabilization and storm protection. Tidal and inter-tidal wetland systems protect and stabilize coastal zones. Coral reefs provide

5346-537: The soil of wetlands. Anaerobic and aerobic respiration in the soil influences the nutrient cycling of carbon, hydrogen, oxygen, and nitrogen, and the solubility of phosphorus thus contributing to the chemical variations in its water. Wetlands with low pH and saline conductivity may reflect the presence of acid sulfates and wetlands with average salinity levels can be heavily influenced by calcium or magnesium. Biogeochemical processes in wetlands are determined by soils with low redox potential. The life forms of

5427-412: The soils and plants at higher elevations. Plants and animals may vary within a wetland seasonally or in response to flood regimes. There are four main groups of hydrophytes that are found in wetland systems throughout the world. Submerged wetland vegetation can grow in saline and fresh-water conditions. Some species have underwater flowers, while others have long stems to allow the flowers to reach

5508-530: The sources of water include tidal wetlands , where the water source is ocean tides ); estuaries , water source is mixed tidal and river waters; floodplains , water source is excess water from overflowed rivers or lakes; and bogs and vernal ponds , water source is rainfall or meltwater . The world's largest wetlands include the Amazon River basin , the West Siberian Plain ,

5589-406: The spatial and temporal dispersion, flow, and physio-chemical attributes of surface and ground waters. Sources of hydrological flows into wetlands are predominantly precipitation , surface water (saltwater or freshwater), and groundwater. Water flows out of wetlands by evapotranspiration , surface flows and tides , and subsurface water outflow. Hydrodynamics (the movement of water through and from

5670-532: The species exhibits minimal sexual dimorphism, with males and females displaying similar plumage. Their beige, streaked, and mottled feathers provide them with camouflage in the reeds and rushes of their wetland environments. The bird is characterised by a long yellow beak, broad neck, and short legs, standing around 75 cm tall, though some individuals may reach up to one metre in height. Juvenile Australasian bitterns have lighter outer wing mottling and yellowish irises, which darken as they mature. Specific details about

5751-1270: The species), suggest a more precarious status. The species' reliance on specific wetland habitats makes it a key indicator for assessing wetland health, as these birds favour particular habitat locations that provide stable water levels and abundant food sources. The Australasian bittern exhibits a diverse, opportunistic diet primarily comprising freshwater aquatic organisms, including fish , frogs , and eels . In addition, they are known to consume some insects and small mammals, such as mice . Research indicates that these birds often hunt for larger prey while foraging. While bitterns primarily consume fish, their opportunistic diet suggests they can adapt to changes in food availability, boosting their resilience to fluctuating food availability. Nevertheless, recent studies reveal that Australasian bitterns face increased nutritional stress due to irregularities in their diet. These irregularities are driven by periods of insufficient access to high-quality food sources, which can negatively impact their growth and reproductive success and deplete their fat reserves. The bittern's barriers to accessing food have been linked to climate change effects, including global warming, urban expansion, habitat destruction, over-exploitation,

5832-719: The surface of the water. When trees and shrubs comprise much of the plant cover in saturated soils, those areas in most cases are called swamps . The upland boundary of swamps is determined partly by water levels. This can be affected by dams Some swamps can be dominated by a single species, such as silver maple swamps around the Great Lakes . Others, like those of the Amazon basin , have large numbers of different tree species. Other examples include cypress ( Taxodium ) and mangrove swamps. Many species of fish are highly dependent on wetland ecosystems. Seventy-five percent of

5913-496: The surface. Submerged species provide a food source for native fauna, habitat for invertebrates, and also possess filtration capabilities. Examples include seagrasses and eelgrass . Floating water plants or floating vegetation are usually small, like those in the Lemnoideae subfamily (duckweeds). Emergent vegetation like the cattails ( Typha spp.), sedges ( Carex spp.) and arrow arum ( Peltandra virginica ) rise above

5994-464: The surrounding environment resulting in increased extinction rates in unfavorable and polluted environmental conditions. Reptiles such as snakes , lizards , turtles , alligators and crocodiles are common in wetlands of some regions. In freshwater wetlands of the Southeastern US, alligators are common and a freshwater species of crocodile occurs in South Florida. The Florida Everglades

6075-611: The surrounding vegetation. Upon approach, they may exhibit a characteristic “freeze response,” silently retreat into the vegetation or flatten their bodies against the ground. They may also slowly take flight as a form of retreat, though this behaviour has been observed only a few times, typically occurring when they are more than 20 metres away from a disturbance or perceived threat. The cryptic behaviour of Australasian bitterns extends to their foraging. Some bittern individuals have exhibited nocturnal behaviours , particularly around dusk and at night when foraging for smaller animals. They adopt

6156-412: The timing and progression of these plumage changes are limited. The Australasian bittern is found in various fresh water wetland environments across New Zealand, south-eastern Australia, south-western Australia, southern Australia and New Caledonia. The biogeographical origins of the species and the dispersal events between Australia, New Zealand, and New Caledonia remain largely unexplored. However, it

6237-440: The types of plants that live within them. Specifically, wetlands are characterized as having a water table that stands at or near the land surface for a long enough period each year to support aquatic plants . A more concise definition is a community composed of hydric soil and hydrophytes . Wetlands have also been described as ecotones , providing a transition between dry land and water bodies. Wetlands exist "...at

6318-472: The wetland were used for travel and recreation and the peat margins were used to preserve taonga such as waka , tools and weapons. Dense vegetation inhibited further use of the wetland, although it was used as a sanctuary during times of war. The Waikato War of 1863–1864 saw several major battles take place in the Whangamarino area, including the fierce land battle at Rangiriri. A small remnant of Rangiriri pā remains today; further north visitors can walk up

6399-679: The wetland. These diverse ecosystems provide habitat to a wide range of native wetland birds, including the Australasian bittern/matuku ( Botaurus poiciloptilus ). Approximately 20 percent of New Zealand's breeding bittern population can be found in the Whangamarino. The wetland is also an important site for a number of other rare or threatened wetland birds, including spotless crake/pūweto ( Porzana tabuensis plumbea ), marsh crake/koitareke ( Porzana pusilla ), North Island fernbird/mātātā ( Bowdleria punctata vealeae ), and New Zealand dabchick/weweia ( Poliocephalus rufopectus ). Occasionally

6480-418: The wetland. Bow hunting for koi carp is increasing in popularity, while bird watching and kayaking are also commonly undertaken activities. 748 hectares of the wetland is owned by the Auckland/Waikato Fish and Game Council and thousands of gamebirds frequent the wetland annually, attracting hunters from Auckland and the greater Waikato area. The Fish and Game Council and gamebird hunters are working together with

6561-468: The wetland. Fencing to exclude stock from wetland areas and restoration plantings have also taken place. Monitoring of Australasian bittern/matuku and other cryptic wetland birds including spotless crake/pūweto, marsh crake/koitareke, and fernbird/mātātā is regularly carried out, as is monitoring of black mudfish/waikaka and threatened plants such as Anzybas carseii and Lycopodium serpentinum . The Auckland/Waikato Fish and Game Council have also implemented

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