CAIRNS’ CATTANA WETLANDS

Contact Call | Volume 11 Number 1 | March 2022



Cattana Wetlands is one of the few lacustrine reserves in Cairns suitable for water birds and waders. It is significant for its wide variety of habitats including several freshwater lakes of different depths (some of which become salty as they dry out), mudflats, fresh to brackish waterways, forest, woodland, and grasslands. A wide variety of habitats means a wide variety of food species, and therefore birds.

Globally, most fauna is declining due to habitat loss, climate change, and other human actions and many species are of particular concern because of greater decline. Cattana Wetlands is a refuge for some of these species.





Introducing Cattana Wetlands Environmental Park


Cattana Wetlands is a well-known, popular birding site close to Cairns. It comprises an area of about 80 ha near Yorkey’s Knob, about 12 kms north of Cairns City. The Traditional Custodians of the Cattana Wetlands region are the Indigenous Yirrganydji people, whose traditional lands and waters extended along the Cairns to Port Douglas coast. Another group, the Djabugay, occupied the mountainous areas and forest to the west.


Today’s wetlands site is named after the Cattana family, who grew sugarcane there before it was sold to the Mulgrave Shire Council in 1993. Part of the property was mined for sand and gravel, resulting in several lakes.


Since then, several grants have been received by Cairns Regional Council (CRC) for rehabilitation and development of visitor facilities at the site, and in 2009 Cattana Wetlands Environmental Park (Cattana) was officially opened. Over the years, several community groups have assisted with rehabilitation plantings, and in 2013 the ‘Jabirus’, volunteers of CRC’s Green Space Our Place program, commenced weekly restoration and maintenance of the site.



Map from Cairns Regional Council website (cairns.qld.gov.gov.au)

A Master Plan approved by CRC in 2017 increased the emphasis on wildlife protection and habitat enhancement. Although major plantings ceased in 2017, maintenance of wildlife corridors and special habitats continues, and the Jabirus continue to support the Park.

Cattana is a protected haven for many water, forest and bush birds; and popular with local, state, interstate, and international birders. Bird hides have been built at Kingfisher Pool and Jabiru Lake (Map 1 above) and there are numerous birding hotspots along the circuit walks at Kingfisher Pool, Cuckoo Lake/Crake Pond; and Jabiru Lake.


Jabiru Lake, is the largest of the Cattana lakes comprised of permanent fresh water to 2m deep, and small islands that provide shelter and roosting vegetation for some birds. During the wet season, all the other lakes are fresh water until, towards the end of the dry season, some become saltier as they dry out. Thus Cattana’s lakes vary from semi-permanent swamps and freshwater lakes to mudflats, or grass/sedge dominated depressions.



About wetlands


Wetlands are defined as areas of land seasonally (at times dry or muddy) or permanently saturated with water, which may be static, flowing, fresh, brackish or saline. They may be natural (eg rivers, swamps, lakes/ponds, floodplains, salt marshes, estuaries, mudflats) or artificial, eg dams, or man-made lakes such as those at Cattana.


Planet Earth needs wetlands: they are a crucial part of our natural environment and it is vital they are protected. Globally, too many wetlands have been drained or filled in for human development. Without wetlands, many birds, other animals and plants just wouldn’t exist. In particular, wetlands are an important habitat for waterbirds. Waterbirds’ body, leg and bill shapes have evolved to enable many species to occupy this specialised habitat.



Bird conservation at Cattana


As birds are such a crucial part of, and indicator of the health of, the world’s environments, numerous government laws and international agreements have been established over the years to protect birds.


These laws include the Australian Environmental Protection and Biodiversity Conservation (EPBC) Act 1999; and in Qld, the Qld Government Environmental Protection Agency (EPA) Nature Conservation Act 1992 (NCA). Further protection is provided by the Commonwealth Wildlife Conservation Plan for Migratory Shorebirds (2015). Many migratory birds breed during northern hemisphere summers when there is a super-abundant food supply for raising the young, then leave the region to avoid the severe winters.


In migrating to their southern hemisphere summer non-breeding grounds, many follow the East Asian-Australasian Flyway (EAAF) which extends from Russia and Alaska, through East and South-east Asia, to Australia and New Zealand.


By 2017 over 45% of the world’s rapidly increasing human population occupied the EAAF region, and associated pollution, land reclamation, hunting, and other threats continue. Loss of rest and refuel (R&R) stopover points along the coast are increasing the risks to birds following the EAAF, despite bilateral International Migratory Bird Agreements (MBA) set up to protect these birds. These Agreements still exist between Australia and: Japan (JAMBA 1974); China (CAMBA 1986); and the Republic of Korea (ROKAMBA 2006).


The International Union for Conservation of Nature (IUCN) maintains a Red List of Threatened Species from which I downloaded (27 January 2022) the conservation status https://www.iucnredlist.org of the species discussed below.


Much of Planet Earth is so disturbed by human activity, that long-term viability of bird populations is also more affected by species lifespan. For example, a species that lives only three or four years, and doesn’t breed until its second year, may only breed two or three times in its entire life, unless it breeds more than once a year. If habitat loss or disturbance prevents breeding in just one year, it may lose at least 25% of its breeding opportunities.


Before humanity had such an impact on the environment, nature’s “boom and bust” cycle was a natural population control, helping to keep nature in balance. In today’s world, wetland destruction and flora and fauna loss make birds much more vulnerable to further change.



Birds recorded at Cattana


At time of writing this article, a comprehensive list of Cattana birds is in preparation. Approximately two thirds are forest and bushland birds, and some use the grassland habitats (eg finches and mannikins). Others use the salt and mud flats (eg the waders Eastern Curlew and Red-necked Stint) and mangroves (eg Black Bittern).


Almost 70 of the birds recorded at Cattana are water species that include not only freshwater birds but also shorebirds (waders), and a classified seabird that also favours fresh and saltwater inland lakes (Australian Pelican). Here are three birds you might see at Cattana’s Lakes, depending on time of year, day, and season.



BLACK BITTERN

Ixobrychus flavicollis


The Qld Government’s Nature Conservation Act (NCA) 1992 records Black Bittern’s status as Least Concern; and IUCN’s Red List (2016 global assessment) records it as Least Concern; population decreasing; average lifespan 4.1 years; full migrant:

https://www.iucnredlist.org/species/22697334/93608997.


However in Australia it’s thought to be sedentary, with some regional movements. Though once considered widespread in Australia, it’s known to have declined over the past 50-plus years due to destruction of river edge habitat for agriculture, as well as increasing salinity of the rivers. Once common in south-western WA, it’s not known to have bred there for over 50 years. In 1992 one author listed it under Taxa of Special Concern. In NSW it was listed in 1999 as Vulnerable, and in Victoria it was classified in 2000 as Critically Endangered.



Black Bittern at Cattana Wetlands by Robert Dowe.

The Black Bittern has a varied conservation history, and in many cases its range is based on few observations. Research is needed to clarify this species’ breeding behaviour, locations and distribution; and to locate the most important breeding areas. Geographic and individual variation patterns are unclear; species variation in plumage and size needs to be re-examined; and its status throughout its range needs to be clarified. (IUCN’s Heron Specialist Group – downloaded 29 January 2022). Much remains to be learned about the Black Bittern.


Bitterns are elusive herons that live in somewhat secret solitude. They have a distinctive habit of freezing like sticks when alarmed: instantly going rigid, feathers compressed to slim their bodies and, with eyes open, stiffly pointing their bills and neck skyward.


Unlike other bitterns, Black Bitterns (aka Yellow-necked Bittern) will come out into the open during daylight, typically freezing when disturbed, but sometimes flying away as in this photo, often to perch in a tree.


Typically, they prefer dense vegetation of permanent wetland margins, where they feed day and/or night at water’s edge. These habitats include forested streams and pools, mudflats and flooded bushland and, particularly in Australia, Pandanus fringed channels in swamps, Melaleuca swamps and coastal mangroves.


When feeding, they slowly stalk or stand to ambush a range of small animals, particularly fish and amphibians. Sometimes they plunge at it from a perch then stab it with their sharp bills.


Little is known about the courtship of this species, and its breeding distribution is little understood. In Australia, it breeds September to April and the nest is a loose platform, with a central shallow depression, in trees over water.


Nesting Black Bitterns with two or three chicks were recorded at Cattana in March 2021; and a pair was using the same nest in January 2022 – Robert and Suan Dowe (pers. comms).

In Australia, Black Bitterns are recorded coastally in WA’s Kimberley, across ‘The Top’ and south through Qld to near Sydney NSW. Agriculture, increasing waterway salinity, and loss of wetlands reduce the range of habitats available for this bird.



EASTERN CURLEW

Numenius madagascariensis


In its October 2021 update, Australia’s EPBC Act 1999 listed Eastern Curlew as Critically Endangered. IUCN states that the global population was estimated at 32,000 individuals in 2015 (undoubtedly during Australia’s summer), including 28,000 in Australia. Global population decline is indicated by reduced numbers along EAAF stopover points in Korea and Japan, and a rapid decline in number of non-breeding individuals wintering in Australia and New Zealand.


IUCN’s Red List (2016 global assessment) records Far Eastern Curlew as Endangered; population decreasing; average lifespan 10.1 years; full migrant: https://www.iucnredlist.org/specieslist.org/species/22693199/118601473



Eastern Curlew on Cairns Foreshore by Jennifer H Muir.


Curlews are large, dull brownish wading birds mainly characterised by very long, decurved bills. Many of these waders, including the Eastern Curlew, breed in the northern hemisphere, and migrate to their southern hemisphere non-breeding grounds, arriving in our spring/summer and departing in autumn.


The Eastern Curlew’s very long down-curved bill is 3.5 times longer than its head. The female is the world’s largest wader and her bill is longer than the male’s.


Stalking slowly and sedately, Eastern Curlews probe the mud with their long sensitive bills for small crabs and other invertebrates on coastal estuaries, mudflats and mangrove swamps.


Most of the world population winters in Australia, arriving around September/October. Eastern Curlews have been recorded at Cattana, as well as at Cairns foreshore’s tidal, marine mudflats. They’re more common on Australia’s north and east coasts than on the west and south coasts. Some individuals winter in China, Peninsula Malaysia, Indonesia, New Guinea and New Zealand. Eastern Curlews breed in eastern Siberia and northern Mongolia on swampy moors and marshes, where their long legs enable them to use areas with taller vegetation: an advantage that shorter-legged species don’t have.



RED-NECKED STINT

Calidris ruficollis


Birdlife International states that Red-necked Stint is considered Near Threatened because it is restricted to the EAAF where loss of key stopover sites in the Yellow Sea region are thought to be responsible for declines in water bird populations. The species is thought to be declining at a rate approaching the threshold for Vulnerable, according to 30 years monitoring data from around Australia and New Zealand.


IUCN’s Red List (2016 global assessment) records Red-necked Stint as NEAR THREATENED; population decreasing; average lifespan 7 years; Full Migrant: https://www.iucnredlist.org.species/22693383/93401907


Stints are the world’s smallest, strongly migratory sandpipers of the genus Calidris: easily distinguished from all other waders, except other dark-legged stints, by their quicker movements. Members of this genus are confusingly alike, at least in non-breeding plumage, presenting considerable field identification challenges.


In Australia, Red-necked Stints ‘hang out’ on tidal mudflats, running about rapidly, pecking at the surface with a sewing machine action, for marine invertebrates when the tide recedes. They roost on rocky outcrops or sandy beaches when the tide rises. They’re also recorded on salt marshes, and brackish and freshwater wetlands with shallow water or wet sand/mud, such as at Cattana.



Red-necked Stint at Michaelmas Cay by Jennifer H Muir.

Breeding plumage on head, neck and breast is orange-red. They breed on the north-eastern Siberia tundra (more rarely western Alaska), then migrate along the EAAF to their southern hemisphere summer non-breeding grounds. Some also stop in eastern China and South-east Asia, or continue on to New Guinea and New Zealand.


In Australia they’re widespread, except in the arid inland: adults arrive August/September and juveniles later. They return to their northern hemisphere breeding grounds March/April.

Like most waders using the EAAF, Red-necked Stints are threatened by coastal pollution, reclamation, and hunting along their migration route.




Article and images by Jennifer H Muir. References available on request.



 


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