Category Archives: Fauna & habitat

Addressing ghost nets in Australia and beyond – update of EMR feature

Britta Denise Hardesty, Riki Gunn and Chris Wilcox

[Update of EMR feature  – Riki Gunn, Britta Denise Hardesty and James Butler (2010) Tackling ghost nets: local solutions to a global issue in Northern Australia, Ecological Management & Restoration, 11:2, 88-98. https://onlinelibrary.wiley.com/doi/10.1111/j.1442-8903.2010.00525.x]

Key words.  derelict fishing nets, ghost gear, GGGI, Indigenous livelihoods

Figure 1. Dead turtle caught in a derelict ghost net. (Photo: Jane Dermer, Ghost Nets Australia)

Introduction. The focus of our 2009 feature was to highlight the work of Indigenous rangers in addressing the local but widespread problem of abandoned, lost or derelict fishing gear (ALDFG) in Northern Australia, particularly ‘ghost nets’ that are carried on the currents and continue to fish long after they are no longer actively used (Figs 1-4). We also aimed to raise awareness of the efforts required to address this complex issue, whilst highlighting the work of Indigenous rangers working in the region.  The feature reported ghost net removal efforts taking place in Australia’s Gulf of Carpentaria – which, by 2009, involved the removal of 5532 nets by over 90 Indigenous rangers from more than 18 Indigenous communities.  This highlighted the transboundary nature of the ghost gear issue, and identified that most nets likely originated from beyond Australia’s waters.

Figure 2. Napranum ranger Philip Mango releasing juvenile turtle trapped in ghost net. (Photo: Ghost Nets Australial)

Further work. Since 2010, the understanding of and approaches to addressing the derelict fishing gear issue have increased substantially. This has been reflected both in domestic efforts within Australia, and more broadly in the international community.

Domestically, in the last decade, the ranger program across northern Australia has evolved and grown, enabling more Indigenous people to remain culturally connected to their land and sea country through meaningful employment.  Ranger activities generally involve a range of restoration activities including feral and weed management, in addition to (for  coastal groups) ghost net removal. Across northern Australia, Indigenous ranger groups continue to remove nets on their country, demonstrating the success of the initial program supported by the Australian government. To date, nearly 15,000 ghost nets (three times the number reported in 2010) have been removed from the region. The net removal program has extended beyond Ranger groups working in the Gulf of Carpentaria to include the Torres Strait, the western part of the Northern Territory Coast, and parts of the Kimberly coastline in Western Australia.

Globally, the world is focused on the United Nations Sustainability Development Goals (SDGs) which aims to provide a ‘shared blueprint for peace and prosperity for people and the planet, now and into the future’ (https://sustainabledevelopment.un.org/sdgs).

A key focus for the SDGs is to help preserve the world’s oceans, a topic which touches on food security, poverty and economic growth, among other goals. Ensuring fishing practices are aligned with these goals includes reducing gear losses into the marine and coastal environment. In recognition of the issue and to end ALDFG, there is now a multi-stakeholder alliance of fishing industry, private sector, multinational corporations, non-government organizations, academics and governments, the Global Ghost Gear Initiative (GGGI), which is focused on solving the problem of abandoned, lost and derelict fishing gear worldwide. Both CSIRO and GhostNets Australia were founding members of this alliance and have been instrumental in engagement and scientific endeavours which inform the GGGI.

Fig 3. An enormous effort is invested by Indigenous rangers in removing ghost nets from beaches along the northern Australian coastline (Photo: World Animal Protection/Dean Sewell)

Based on collaborative research between GhostNets Australia and CSIRO, it was determined that the primary source of derelict nets washing ashore along Australia’s northern coastline was the Arafura Sea. Engagement with fishers in the region through a series of workshops identified that major causes of gear loss included snagging of nets and over-capacity in the region. We also identified opportunities to help resolve ghost net issues in the region, though stakeholder engagement, points of intervention and livelihood tradeoffs. Much of this overcapacity and overcrowding has been attributed to illegal, unreported and unregulated (IUU) fishing. Subsequently, Indonesia went through a substantial change in practices with regards to allowing foreign vessels in their waters, effectively closed their borders to foreign fisheries operators. Anecdotally, information from multiple ranger groups in Northern Australia suggests that this highly publicized and significant change in practice has resulted in a substantial decrease in the number of ghost nets washing ashore along at least part of the northern Australian coastline.

Another outcome from the collaborative research effort was a new understanding based on deep citizen science engagement and modelling to identify potential high risk areas where ghost nets were likely to cause the most harm to turtles. In this work, we were able to suggest interdiction points for ghostnets, before they entered the Gulf of Carpentaria where they were likely to kill wildlife. We also identified the nets that were most harmful to wildlife and we estimated that nearly 15,000 marine turtles had likely been killed by derelict nets in the region.

There have also been some technological improvements in this area. These fall into both reporting and in tracking nets. Electronic data collection has improved the quality of data collection and can ensure errors are minimised. Development of the tool has also been designed such that those with reduced literacy are also able to collect valuable information, a feature that can be important in many communities. Using icons and photos to help identify nets improved data reliability.

Also within Australia, alternative livelihoods programs such as Ghost Net Gear evolved into the Ghost Net Art Project where the art works have excited the International art community.  This has resulted in purchases by many internationally renowned purveyors of artwork including the British Museum, the Australian National Museum and the Australian Maritime Museum. Works from Indigenous artists can also be seen at Australia’s Parliament House, and exhibitions have taken place in Monaco, Alaska, Singapore and France as well as in numerous national and regional galleries around Australia. A commemorative stamp was even made from the Ghost Nets artwork that lives in the Australian National Museum.

Figure 4. Large nets can become entangled in coastal vegetation. (Photo: World Animal Protection/Dean Sewell)

Future directions. While GhostNets Australia has not formally continued as a non-governmental organization, many of the components initiated through the program have continued and grown through time, as exemplified above. This early work also helped springboard CSIRO’s engagement in capacity building with the Indonesian government to tackle Illegal, Unreported and Unregulated (IUU) fishing. This had led to a strong research collaboration relationship between the two countries, with a shared goal of reducing IUU fishing, building capacity on marine resource management, and improved monitoring, control and surveillance efforts in Indonesia.

CSIRO is also involved in an aerial (re)survey of the coastline across Northern Australia. In affiliation with World Animal Protection and Norm Duke and Jock Mackenzie from James Cook University, we are looking at changes in the number of ghost nets along the shoreline. Stereo images were recorded along the entire coastline and we are comparing ghost nets observed across the region with two other aerial surveys that have taken place in the last decade. The team have just completed flights (September 2019), so we are looking forward to analysing the images and comparing ghost net numbers across the region.

ContactDenise.hardesty@csiro.au; CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia. rikigunn1@outlook.com; chris.wilcox@csiro.au

Rehabilitation of former Snowy Scheme Sites in Kosciuszko National Park – UPDATE of EMR feature 2019.

Gabriel Wilks

Update of EMR feature – MacPhee, Elizabeth and Gabriel Wilks (2013) Rehabilitation of former Snowy Scheme Sites in Kosciuszko National Park.  Ecological Management & Restoration, 14:3, 159-171. Doi https://onlinelibrary.wiley.com/doi/10.1111/emr.12067

Key words.  Habitat construction, steep slopes, rock spoil.

Figure 1. Shaped rock spoil ready for planting more than 50 years after being dumped.

Introduction. Our original EMR feature article described the origins of this large, long-term rehabilitation program and the challenges faced in the first 10 years. The program’s aim was to address a range of impacts upon montane and sub-alpine vegetation and river corridors in Kosciuszko National Park from the Snowy Hydro Scheme, constructed from 1949 to 1974. Impacts included dumping of large volumes of rock spoil, loss of topsoil and native vegetation, introduction and spread of weeds and asbestos fragments in the landscape.  The article outlined the development of methodologies for restoration, particularly planting trials on steep rock spoils, and how obstacles such as slope instability, plant material availability and lack of soil were being overcome. The process of program implementation was given, including environmental and cultural heritage assessments undertaken as part of site works.  In 2013 a number of positive outcomes were already evident at the 200 sites that had been subjected to at least some treatment, including 18 sites where major rehabilitation works were undertaken. Outcomes included reduction in waterway impacts and invasive weeds, expansion of the Kosciuszko fauna database, regional community benefits, and production of an Australian Alps Rehabilitation Field Guide.

Further work. The Former Snowy Scheme Rehabilitation Program continues to reduce the long term environmental and safety risks of old degraded construction sites to Kosciuszko National Park, as well as improve their visual and ecological function. Some sites treated by 2013 have blended in with the surrounding landscape and are difficult to identify. Many sites are continuing to improve in condition over time, with distinct vegetation layers, natural plant recruitment and evidence of native fauna habitat. Construction history, rock spoil and loss of soil and plant species remain evident at highly altered sites, despite a high standard of rehabilitation work.

An additional 12 Major rehabilitation works have been undertaken since 2013, with selected signature projects and rehabilitation techniques described below.  Note that the former Snowy Scheme rehabilitation program does not address the impact of current Snowy Hydro Limited or proposed infrastructure and support networks such as powerlines, easements, river regulation or roads.

1. Rehabilitation of the Tooma–Tumut Access Tunnel Adit Spoil Dump. This spoil dump (Fig. 1) is located on the highly incised upper reaches of the Tumut River.  The spoil originates from construction in 1958-1961 of the Eucumbene–Tumut Tunnel, which transfers the headwaters of the Tooma River to Tumut Pond. Following earthworks in 2017, the planting crew successfully planted, watered, fertilised and mulched approximately 12,000 plants on rock spoil, with monitoring being undertaken by Greening Australia Capital Region staff (Fig 2.)

Figure 2. Year 1 Revegetation monitoring at Tooma-Tumut SD by Greening Australia Capital Region staff, 2018

2. Construction of contained habitat for the Southern Corroboree Frog. A series of remote enclosures (Fig 3) have been constructed in both rehabilitation areas and former habitat locations to enable re-introduction of this Critically Endangered species (Fig 4), following the devastating impacts of chytrid disease. These enclosures are developing essential stepping stones for frogs from captive breeding programs to move back into the wild. Design of enclosures requires ensuring self-sustaining food and water, shallow ponds for breeding, ability for Threatened Species staff to monitor and control disease and exclusion of other frogs. These works have been done in partnership with NSW Threatened Species staff and zoo institutions.

Figure 3. Constructing Southern Corroboree Frog enclosures in remote locations

Figure 4. Southern Corroboree Frogs living successfully back in Kosciuszko

3. First live record of Smoky Mouse in Kosciuszko National Park. The Smoky Mouse (Pseudomys fumeus Fig. 5) was found alive and well for the first time in Kosciuszko National Park, at a Happy Jacks rehabilitation site. Up until the discovery, the only currently known population of the small, smoky grey coloured mouse still surviving in NSW was in the Nullica area, NSW South Coast.  Three individuals, 2 males and 1 female were a significant find for survival and database records of this Critically Endangered Species, and a technical short note was published in EMR in 2017 by fauna surveyor Martin Schulz who found the animals.

Figure 5. A Happy Jacks Smoky Mouse.

4. Making people and places safer with rehabilitation. Sites that housed construction depots and townships during Snowy scheme construction still contained fragments of asbestos which were rapidly degrading due to weather exposure. As total removal was not feasible, the rehabilitation team worked with asbestos experts to develop practical measures to reduce public safety risks. At the remote Junction Shaft Contractors Camp (at Happy Jacks, Figs 6 and 7) and a former township and current camping ground at Island Bend a range of techniques were developed, delineation of zones for suitable uses, creating natural vegetation buffers and capping with rock spoil and plants.

Figure 6. The Junction Shaft Camp in 1955.

Figure 7. The same site 62 years later (and one year after works) with a range of capping and planting zones, including a heli-pad, Mountain Pygmy Possum habitat, and new plantings to improve safety and environment.

5.  Applying techniques beyond Kosci. Project team members took some winter time out of Kosciuszko to ‘grow’ a protection zone for a known population of Endangered Green and Golden Bell Frog (Litoria aurea) and constructed a series of ponds for future breeding in an old sand quarry at Worrigee Nature Reserve, Nowra (Fig 8). Given former quarries are a feature of a large infrastructure project such as the Snowy Scheme, the team had the technical knowledge for how to restore ecological function despite a radical departure from usual flora and fauna species. A range of techniques including neighborhood consultation, barrier logs and blocks, berms and vegetation were used to reduce the impact of recreational and unauthorised motorbikes and rubbish dumping.

Figure 8. Creating Bell Frog habitat in degraded borrow pits.

6. Growing rehabilitation resources and protecting karst ecosystems. The use of treated waste at the Yarrangobilly Caves visitor precinct to grow snow grasses (Poa spp.) for use in rehabilitation projects across Kosciuszko and been continued and developed (Fig. 9). A renewed emphasis on site production has enabled Poa seed to be available for other projects within the Park. This provides an ecologically preferable option for soil stabilisation and ground cover establishment, reducing the risk of weed invasion and dependence on sterile rye corn as the only available option.

Figure 9. Inspecting plants for seed harvest, which yielded 52 kgs of Poa seed in 2017.

Lessons Learned. It is clear that this is a unique rehabilitation project due to the large number of sites, the natural and heritage values of Kosciuszko National Park and the longevity and continuity of the commitment (approx. 20 years).  Understandably, however, at this point in time challenges in rehabilitation remain. ‘Off the shelf’ rehabilitation products are limited due to remoteness of locations, plant species required, Park management policies and required hygiene protocols. It is important that additional threats are not accidentally introduced, such as foreign pathogens and flora and fauna. As much as possible, resources such as coarse woody debris, woodchip, plant material and compost are sourced from within the Park. A flexible and dynamic approach to the very definition of rehabilitation and techniques and materials is required.  Specific lessons include the following.

Adding organic material on degraded sites is always beneficial. Rehabilitation success has been most obvious where logs, litter, woodchip and straw have been added to the site, to provide mico-niche climate, habitat, and improve soil. While this may increase short term management requirements such as weed control, the commitment is worth it due to the improved results.

Creating compost from old sawmill sawdust has worked well for this rehabilitation project. The most recent development however is in the use of organics waste and treated effluent from visitation facilities as a compost, and there is opportunity for this on-Park recycling to develop.

Other resources such as rice straw have become limited during periods of sustained drought and less rice production. This will remain a challenge into the future. The value of minimising ground cover loss, retaining natural soil characteristics and organic matter in situ and ensuring rapid rehabilitation after disturbance in future developments will become increasingly important for rehabilitation success.

Be creative with team skills and capacity. Problems such asbestos contaminant presence must be addressed for safety, but doesn’t mean walking away from the challenge. A degraded site may be the perfect place to develop species targeted habitat.  Seek expertise advice and consider a range of current and new solutions.

ContactGabriel Wilks, Senior Project Officer, NPWS Southern Ranges Services. PO Box 472, Tumut NSW 2720.  Email: Gabriel.Wilks@environment.nsw.gov.au

Still repairing wetlands of the Lower Murray: continuing the learning – UPDATE of EMR feature

Anne Jensen

[Update to EMR feature – Jensen, Anne (2002) Repairing wetlands of the Lower Murray: Learning from restoration practice. Ecological Management & Restoration, 3:1, 5-14. https://onlinelibrary.wiley.com/doi/10.1046/j.1442-8903.2002.00092.x]

Key words:         Environmental water requirements, regeneration, wetlands, black box seedlings, Lower Murray Valley

Figure 1. Location of the Lower Murray Valley in South Australia (Map A. Jensen)

Introduction. As highlighted in the original EMR feature this summary is updating, in the Lower Murray Valley 1100 wetlands have been identified in 250 hydrologically-linked complexes (Fig. 1). They have undergone major changes to their water regime over the last 100 years, altering the timing, frequency and duration of floods. Wetlands at lower elevations have become permanently flooded by stable river levels and wetlands at higher elevations are ‘droughted’ by much reduced flooding. All would benefit from environmental watering, to fill gaps in breeding and regeneration cycles.

Our 2002 feature showed that, from 1998 to 2002, the not-for-profit conservation company Wetland Care Australia coordinated on-ground projects to repair priority wetlands in the Lower Murray. The Gurra Gurra project was the largest of these projects, with engineering works at 17 sites to restore multiple flowpaths through the 3000 ha floodplain complex.

Key funding from the National Heritage Trust terminated in 2002 and Wetland Care Australia relocated in 2003 to northern New South Wales, where project funding for wetland projects was still available. However, individuals involved with the Wetland Care Australia projects remained in the Lower Murray Valley in other jobs, so the intellectual property was retained and wetland conservation activities continued.

In 2002, the extent and severity of drought conditions in the Murray River Valley were just being recognised. By 2004, a survey estimated that >75% of the two main tree dominants in floodplain woodlands –  River Red Gum (Eucalyptus camaldulensis) and Black Box (E. largiflorens)  – were dead, dying or extremely stressed along 700 km of the Murray River Valley . The Millenium Drought (2000-2010) caused extreme stress to both ecological and human communities. Government agencies commenced emergency environmental watering from 2004 through the Living Murray program to limit catastrophic damage at eight iconic sites but millions of mature eucalypts were lost from floodplain woodlands along river valleys.

The Millenium Drought changed the governance context radically, with the Water Act 2007 establishing a new Murray-Darling Basin Authority and the Basin Plan. The Commonwealth Environmental Water Holder (CEWH) was able to purchase water for environmental use.

Nature delivered life-saving floods in 2010-12, which broke the drought and sent flows through the Gurra Gurra complex flowpaths, so the works completed back in 2000 finally fulfilled their function (Fig. 2). Water flowed through the pipes at Tortoise Crossing for 170 days in 2010-11 and again for 71 days in 2012.

Figure 2. The sign at the key Tortoise Crossing flow path explains that replacing three pipes with 160 pipes back in 2000 now allows 50 times more flow when the river floods, as seen at the flood peak in December 2016 (Photos A. Jensen)

The sequence of floods led to mass germination of Black Box at medium floodplain elevations, with mass River Red Gum seedlings at lower elevations. A range of studies show that the survival of these seedlings is critical to fill age gaps and replace the losses from the Millenium Drought, as survival rates from germination events in the 1970s and 1990s were very poor and the last successful mass recruitment of Black Box in the Lower Murray Valley was from the 1955-56 floods.

Following the floods in 2010-2012, conditions were dry in 2013-15 and the fields of mass seedlings began to dry out and die. A further short flood in 2016 watered the surviving fields of Black Box seedlings for at least two weeks, adding to prospects of survival and flowing through the Tortoise Crossing pipes for 75 days. However, conditions in 2018-19 and into summer 2019-20 are once again extremely dry, with stress appearing in mature trees and saplings dying off. The Lower Murray Valley is still recovering from the Millenium Drought, thus needing more frequent watering over a sequence of years to bring mature trees back to health and full seed production, so this is a significant setback.

Further works and activities since 2002. Since 2008, the environmental charity Nature Foundation SA (NFSA) has been undertaking environmental watering projects on smaller, privately-owned sites in the Lower Murray, many from the original Wetland Care Australia list. In the Lower Murray Valley, water needs to be lifted up to 3 m from the river channel to reach wetlands on the floodplain, requiring costly energy. This is done using irrigation techniques, including pumps, pipes and sprinklers. These smaller projects complement government agency projects using major infrastructure to deliver environmental water to much larger wetland complexes.

In 2008-09, the primary purpose was to acquire water and use it to limit extreme environmental damage in the drought. In 2009 NFSA provided supplementary water for Little Duck Lagoon, one of the sites from the Wetland Care Australia Gurra Gurra project.

From 2012-19, NFSA has held a contract partnered with the Commonwealth Environmental Water Holder (CEWH) to deliver up to 10 GL/y of environmental water to selected sites. A priority for the NFSA Water for Nature program has been to sustain the mass germination triggered by the 2010-12 floods, watering fields of seedlings and saplings so they can fill the very large gap in age structure of Black Box populations. Stressed mature Black Box trees are being watered to improve their condition and volumes of seed produced. While delivering water to a defined wetland is relatively simple, with water pumped to an inlet point and allowed to pool in the wetland, watering scattered fields of seedlings and saplings on relatively flat floodplain land is a challenge, especially when they are in gaps between mature trees. The solution has been to use high-throw sprinklers (simulating rainfall) and operating them at night, to allow soakage into clay soils and to avoid evaporative loss during the day.

Since 2008, NFSA has delivered almost 13 GL of water to 97 watering sites in 20 wetland complexes, covering 27 different ecological targets across 12 habitat types. A total of 4.9 GL was delivered to 15 sites in 2017-18 and 1.55 GL was delivered in 2018-19 to 25 sites covering 126 ha. Rolling 5-year watering plans have been developed for each site, able to respond to annual water availability, Basin-wide priorities, environmental water requirements, climatic conditions, site watering history and feasibility of delivery.

One of the NFSA sites is Lyrup Lagoon in the Gurra Gurra complex, being watered to reduce accumulated salinity from groundwater inflows. Importantly, the infrastructure of the Central Irrigation Trust was used to deliver water to the lagoon. Thus, local irrigators are partners in delivery of water for regional environmental benefits and river health.

Figure 3. Watering guidelines developed by the Water For Nature program for stressed and healthy woodlands, for (a) River Red Gum and (b) Black Box (Water for Nature).

Further Results. The initial watering guidelines reported in the original EMR feature have been expanded through research and monitoring of responses to watering events, developing guidelines for timing and frequency of wetting and drying cycles to promote recovery in mature trees and support germination and survival of seedlings. These have been applied for each site in the rolling 5-year watering plans, which then determine the annual list of sites due for watering (see NFSA 5 year strategy and Fig. 3).

Watering by NFSA 2013-2019 has sustained Black Box seedlings and saplings through four dry summers, with watered plants 2-3 times taller than non-watered plants (Fig. 4). The Water For Nature monitoring report shows that, at NFSA sites, mature Black Box trees that have received periodic environmental water as determined by their 5-year watering plan during 2015-2019 were 21-46% (average 36%) better in health than adjacent non-watered sites, with denser, more vigorous canopies and the relative improvement was greatest during hotter and drier periods. The watering events thus provided water between natural floods to sustain growth in saplings and crop cycles in mature trees. Watering at other NFSA sites has provided vital habitat for vulnerable and endangered fauna including the Murray Hardyhead (Craterocephalus fluviatilis), Southern Bell Frog (Litoria raniformis), Regent Parrot (Polytelis anthopeplus) and Latham’s Snipe (Gallinago hardwickii).

Figure 4. Watered River Red Gum saplings at Thiele Flat, Loxton; November 2013 (top) and March 2018 (bottom). Note 2016 flood level mark on foreground trees (Photos A. Jensen)Lessons learned and future directions.

The significant benefits of environmental water have been demonstrated at NFSA’s Water For Nature sites, for floodplain vegetation communities and in temporary wetlands. Evolving research indicates that watering in late spring-early summer mimics peak flows in the natural water regime, coinciding with highest chances of breeding and germination events and thus ecologically ideal timing (See bibliography). Benefits are increased if seasonally filled wetlands are topped up in early summer, to ensure sufficient duration to sustain frog and waterbird breeding.

As well as ideal timing, studies have shown that watering at any time of the year can be beneficial, including enhancing soil moisture storage in the unsaturated zone and sustaining volume in bud and fruit crops. A key finding has been that watering in late autumn-early winter sustains soil moisture, priming sites to give an enhanced response to watering in the following spring-summer.

However, dry climatic conditions and political pressures to minimise water recovery volumes are combining to reduce availability of environmental water, with only very highest priority sites likely to receive water in the 2019-20 water year. Environmental water cannot create floods, it can only provide water to selected priority sites during dry times and enhance the benefits of any natural floods. Current volumes can only meet the requirements of a limited number of sites, leaving many sites without the water needed to sustain them through dry times or to recover from the severe impact of the Millenium drought.

Bureaucratic processes for approvals also hinder effective delivery of environmental water. With the water year coinciding with the financial year from July to June, water delivery stops in June to allow water accounts to be finalised. Approval to water in the following year can take 2-3 months, meaning no water can be delivered during the winter months for priming, missing the advantage of low evaporation rates and higher chances of piggy-backing on rainfall events.

Funding for environmental projects tends to be short term, leading to job insecurity for project managers, loss of continuity and project knowledge, and inability to complete watering sequences. Very significant volunteer resources are required to make these watering projects happen, including inputs from landholders who have donated electricity connections to the floodplain, transported diesel to re-fuel pumps, loaned pumps, tractors and irrigation equipment, plus use of irrigation and local government infrastructure to deliver water, and physical assistance and maintenance from local volunteer groups.

Practical on-ground watering knowledge is maturing well; what is needed now is sufficient water and ongoing consistent funding to support projects to deliver minimum environmental water requirements for the wetlands of the Lower Murray Valley. The pipes at Tortoise Crossing, installed in 2000 and only flooded twice, are more than ready for the next high flows to pour through!

Stakeholders and Funding bodies. The monitoring project was supported as part of the project Ecological Responses to Environmental Watering in the South Australian River Murray Valley, assessing the benefits of salinity interception schemes on floodplain vegetation, coordinated by Australian Water Environments for SA Water from March 2015 to June 2017. Continuing funding for monitoring in 2017-2019 was provided in a grant from the Ian Potter Foundation to Nature Foundation SA, as well as funding from the Commonwealth Environmental Water Holder (2018-19). Water for the environmental watering projects studied here was provided through annual allocations of water from the Commonwealth Environmental Water Office to Nature Foundation SA.  Water delivery was managed by the NFSA Water For Nature program through Program Manager Natalie Stalenberg. Practical support and site access was provided by Steve Clark, landholder and committee member for Water for Nature program, and landholders John and Bronwyn Burford.

Contact. Dr Anne Jensen, Environmental Consultant; Volunteer member, Water for Nature Committee, Nature Foundation SA; part-time consultant Wetland Ecologist for Water for Nature Program of Nature Foundation SA (7 Ford Street, Maylands SA 5069, Australia; Tel: +61 407 170 706; Email: ajensen@internode.on.net

The rise of invasive ant eradications since the success of the Kakadu project  – UPDATE of EMR feature

Benjamin D Hoffmann

[Update of EMR feature – Hoffmann,  Benjamin D and Simon O’Connor (2004) Eradication of two exotic ants from Kakadu National Park. Ecological Management & Restoration, 5:2, 98-105. https://onlinelibrary.wiley.com/doi/10.1111/j.1442-8903.2004.00182.x]

Key words. pest species management, invasive species, biosecurity

Figure 1. Kakadu staff in 2001 spreading formicide over a super-colony of African Big-headed Ant. This involved a team of people, aligned in a row, walking from one edge of the infested area to the other in parallel paths. (Photo courtesy of Simon O’Connor.)

Introduction. Invasive species management, especially eradications, has been at the forefront of biodiversity conservation gains over the past two decades. For example, over 1,200 invasive vertebrate eradications have been achieved on over 800 islands worldwide and the conservation benefits of such actions have been overwhelmingly positive and often dramatic. Efforts against invasive ants have also been particularly notable over the past two decades, with ants now being the second-most eradicated taxa globally having been eradicated from more than 150 locations, with the largest eradication covering 8300 ha. Two decades ago there were only 12 confirmed ant eradications using modern baits with a combined area totalling a mere 12 ha.

As reported in our original EMR feature, the last treatments against two invasive ants in Kakadu National Park, northern Australia: The African Big-headed Ant (Pheidole megacephala) and the Tropical Fire Ant, (Solenopsis geminata) were conducted in 2003; and the ants were declared eradicated two years later (Hoffmann & O’Connor 2004). At the time this was a globally significant eradication, and the positive outcome was a partial catalyst for the creation of many other relatively small exotic ant eradication attempts around Australia, including against Tropical Fire Ant on Melville island, and African Big-headed Ant on Lord Howe Island. Incidentally, the work coincided with the approximate timeframe of when two other highly invasive ant species were first detected in Australia: Red Imported Fire Ant (RIFA) (Solenopsis invicta), and Electric Ant (Wasmannia auropunctata), prompting the initiation of two massive national cost-shared eradication programs. One of these, the RIFA program, has become Australia’s second-most expensive eradication program at AUD $428 million as of at July 2019. Together, all of these actions put ants high on Australia’s biosecurity and environmental management radars, prompting the development of Australia’s Tramp Ant Threat Abatement Plan and yet even more eradication programs.

Figure 2. Ant bait being dispersed aerially by helicopter using an underslung spreader and side-mounted dispersers. (Photos Ben Hoffmann)

Further advancements in ant eradication programs.  As Australia’s eradication programs became more numerous and larger, it became apparent very quickly that the methodologies and technologies available were insufficient to achieve success in the increasingly challenging conditions being encountered. In response, over the next two decades, there has been an impressive range of advancements that significantly improved our capacity to manage and eradicate invasive ant incursions.

The biggest issue was that work needed to be conducted over such large or inaccessible areas that ground-based work (Fig 1) was not feasible. So, treatments quickly became aerial, using multiple helicopter-based delivery platforms (e.g. underslung buckets and side-mounted hoppers, Fig 2). Even so, there have been locations that are too remote, too small, or too difficult (ie cliffs) to treat using a helicopter. To meet this challenge, in just the last five years treatments have been conducted for the first time using drones, and there is a great focus now to improve the technology so that it becomes more cost effective and more autonomous (Fig 3). This is occurring at such a pace that just a few years ago drones could only operate for a few hours at most on battery power, and only carry a few kilograms. This year we will be using a drone with unlimited flying capacity (petrol driven) that can lift 70 kg per load.

Figure 3. The Fazer with side-mounted bait carriers that can lift up to 40kg of payload. This is soon to be superseded by a drone that can lift a 70k g payload. (Photo Ben Hoffmann)

Assessments for the presence of ants, either before or after treatments, was originally very time consuming, involving teams of people walking ground very slowly and often utilising thousands of attractive lures (Fig 4). At most, only small ant populations (about less than 20 ha) within good working environments (ie open landscapes) could be assessed using teams of people, and it took large amounts of time. It was found very quickly that detector dogs could be trained on the scent of each ant species, and a single dog could cover more than five times the area of a team of people in a single day with greater efficacy (Fig 5). There are now more than 20 detector dogs operating in Australia and New Zealand that have been trained on the scent of four ant species. But even a team of dogs cannot fully cover entire areas at the landscape-scale, such as is the case for the RIFA program, especially in areas with long grass or rugged terrain. One of the saving technologies for the RIFA program has been the development of a multi-spectral sensor and associated algorithms that can identify RIFA nests from imagery captured by remote sensing (Fig 6). This allows program staff to assess just a few identified point locations in a landscape rather than the entirety of landscapes, to determine RIFA presence or absence. The next envisaged step is the development of biosensors that can detect the odours of target ant species, just like detector dogs, and with time these will become small enough to be transported by small drones throughout landscapes to detect ants.

Figure 4. An area covered with hundreds of flags marking spoonfulls of catfood being used as lures to attract African big-headed ant to assess eradication success or failure. (Photo Ben Hoffmann)

Figure 5. An ant detector dog searching for the presence of Red imported fire ant. (Photo courtesy of The State of Queensland (Department of Agriculture and Fisheries 2010–2019))

Australia was caught particularly unprepared two decades ago when the two new exotic ant species were detected for the first time because there were no baits registered for their management in Australia, so legally there were no treatment products that could be used. Even with the implementation of Emergency Use Permits for some unregistered products, as well as the use of the few products that were available for other species, it was often found that individual products could not be used in particular circumstances, especially around water, within crops and on organic farms. Additionally, available baits often did not have high efficacy. With time many baits (comprised of combinations of an attractive food laced with an active constituent) have been formulated and tested providing a greater array of baits that can be used on any new incursion and in numerous settings. The most recent has been the development of hydrogel baits that essentially deliver a liquid product in a solid form.

Figure 6 a and b. Multi-spectral camera flown underneath a helicopter to detect Red imported fire ant nests. (Photos courtesy of The State of Queensland (Department of Agriculture and Fisheries) 2010–2019)

Among the numerous advances described already, possibly the greatest development is on the threshold of becoming a reality, in the form of genomic solutions for individual species. RNA interference, and gene-drive technology are rapidly being developed for a suite of economically important species, and ants are among the taxa that are highest on the priority list as targets for this research. At best, these genomic advances promise to provide species-specific solutions, thereby alleviating the current non-target issues of using toxicants.

Conclusion. Our ability to eradicate ants has improved dramatically over the past two decades, with technologies and methodologies available now that were as yet not thought of back when our work was conducted in Kakadu National Park. New programs are constantly arising, and forging ahead in increasingly challenging situations, and a great deal of effort is placed in information-sharing among programs. Simultaneously there is a sustained focus to improve biosecurity at Australia’s borders, as well as throughout our region to help prevent the need for eradications in the first place.

Contact. Ben Hoffmann, Principal Research Scientist, CSIRO Health & Biosecurity (PMB 44 Winnellie NT 0822 Australia; Tel: +61 8 89448432; Email: Ben.Hoffmann@csiro.au).

Registration of domestic cats on Christmas Island, Indian Ocean: stage one to an eradication program for stray and feral cats to mitigate social and environmental impacts – UPDATE of EMR feature

 David Algar, Neil Hamilton and Caitlyn Pink

[Update to EMR article: Algar, David, Stefanie Hilmer, Don Nickels and Audrey Nickels (2011) Successful domestic cat neutering: first step towards eradicating cats on Christmas Island for wildlife protection. Ecological Management & Restoration, 12:2, 93-101. https://onlinelibrary.wiley.com/doi/10.1111/j.1442-8903.2011.00594.x]

Key words: domestic and feral cats, eradication program, cat de-sexing and registration, cat management, pet cat survey, local cat legislation

Figure 1. Stray cat on Christmas Island (Photo Neil Hamilton DBCA)

Introduction: In 2010 a ‘’Cat Management Plan’’ was commissioned by the various land management agencies on Christmas Island to mitigate the environmental and social impacts of cats (Felis catus) on the island (Fig 1). These impacts included contributing towards the decline of a number of native species through predation, as well as being a source of Toxoplasmosis gondii, a parasite that can lead to serious human health complications.

The plan proposed a strategy to eradicate cats entirely from the island as the domestic population died out and was adopted in late 2010. The essential first stage of the management plan was therefore the registration of all domestic cats. As part of this plan, amendments to the Local Cat Management Laws (Shire of Christmas Island Local Law for the Keeping and Control of Cats 2004 (WA)) under the Local Government Act 1995 (WA) were endorsed in August 2010. These revisions required that all domestic cats in the Shire of Christmas Island were legally bound to be de-sexed, tattooed, microchipped and registered with the Shire. The revisions were designed to limit domestic and stray/feral cat impact on the native fauna, promote responsible cat ownership, compliance and enforcement of cat management laws and prohibit the importation of new cats. Micro-chipping of domestic cats would enable the identification of those animals during trapping campaigns for stray and feral cats, so that they could be released rather than destroyed. De-sexing would prevent potential natal recruitment into the domestic, stray and feral populations. A survey of domestic cats was conducted prior to the veterinary program in October 2010 (see original feature), to guarantee that all domestic cats would be registered. One hundred and fifty-two cats were recorded during the initial survey in October 2010 of which 136 were registered as domestic pets.

Figure 2. Red-tailed Tropic-Bird with chick May 2012. (Photo Neil Hamilton DBCA)

Further works undertaken: Two further veterinary visits were conducted in May 2011 and 2012 following the domestic cat surveys to complete the veterinary program. Subsequent domestic cat surveys have been conducted each May in 2013, 2014, 2015 and 2016. In 2016 prior to the domestic cat survey, it came to our attention that a number of un-registered cats were being kept as pets. It was decided by the ‘’Christmas Island Cat Eradication Steering Committee’’ that a short-term amnesty on pet cat ownership be invoked so that these animals could also be de-sexed and registered. Following this amnesty, a final veterinary program was endorsed and fines were still issued to those residents who wanted their otherwise illegal cat to be de-sexed and registered, or unregistered cats could be handed in and euthanased without charge. Further domestic cat surveys were conducted in May 2017 and October 2018.

Further results to date: Since October 2010, 184 cats have been registered following the various veterinary programs. The survey conducted in 2018 recorded 66 registered cats remaining. The total number of domestic cats registered each year, the sex population structure, the number of new registrations and number deregistered are presented in Table 1, with the decline of two-thirds relatively steady over the years.

Table 1. Total number of domestic cats registered each year, the sex structure, the number of new registrations and number de-registered.

Date No. registered New/re-registers De-registers
  Total Female Male Total Female Male Total Female Male
October 2010 N/A N/A N/A 136 66 70 N/A N/A N/A
May 2011 138 69 69 18 10 8 16 7 9
May 2012 135 66 69 12 5 7 15 8 7
May 2013 111 53 58 0 0 0 24 13 11
May 2014 101 50 51 0 0 0 10 5 5
May 2015 87 45 42 0 0 0 14 5 9
May 2016 75 41 34 2 1 1 14 5 9
June 2016 93 49 44 18 8 10 0 0 0
May 2017 74 38 36 1 0 1 20 11 9
October 2018 66 36 30 0 0 0 8 2 6

Lessons learned and future directions: At the conclusion of the domestic cat survey in 2018, there were 66 registered cats present on the island. An additional seven domestic cats are known to have died before the planned 2019 domestic cat survey. Death of registered cats over the past nine years has been caused by a number of factors including: road fatalities; old age; disease; requests for cats to be euthanased for a variety of reasons and cats exported back to the mainland.

Domestic cats will remain on Christmas Island for a number of years, with the youngest cat approximately three years of age. Initially, as reported in the 2011 feature, it was predicted that the island would be domestic cat-free by 2024 however, this is unlikely given the subsequent and final veterinary program in 2016.

Further amendments to the island’s cat local laws were adopted in 2018, following consultation with the community and the Christmas Island Cat Eradication Steering Committee. This included an increase in penalties for illegal unregistered cats and compulsory transfer of ownership procedures to prevent future movement of registered pet cats into the designated pet cat prohibited zone. This zone protects nesting habitat for the ground-nesting Red-tailed Tropic Bird (Phaethon rubricauda, Fig 2.), where cat predation led to 90% failure of fledgling rates pre-control. Subsequent cat management in this zone has been successful in improving fledgling survival (See 2012 report).

There are several benefits of repeating the domestic cat survey each year as pet numbers decline: continue program awareness to all residents; maintain community support and involvement; offer pet health advice; thoroughly check for illegal cats to report to the Shire and respond to stray cat reports within the township. This continued effort will help ensure there is little opportunity or temptation to obtain new kittens as illegal pets while later stages of the eradication are progressing, and responsible cat ownership is maintained until the domestic cat population has died out.

The goal of eradicating cats remains highly relevant and is supported by the island community, local land management agencies and the federal government. The feasibility of long-term success is high and the outcome is likely to provide valuable lessons for other jurisdictions with social and environmental issues surrounding the presence of feral and domestic cats.

Stakeholders and Funding bodies: This is a collaborative project between Western Australian Department of Biodiversity, Conservation and Attractions and Parks Australia. The authors would like to thank Parks Australia, Christmas Island Phosphates, Shire of Christmas Island, Department of Infrastructure, Transport, Cities and Regional Development and Australian Border Force for their financial, in-kind and logistical support. Special thanks to Robert Muller, Khaleisha Amin and Chris Su for their assistance in annual surveys. The warm welcome and assistance of the whole Christmas Island community during all domestic cat surveys has been appreciated.

Contact information: David Algar, Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions (Locked Bag 104, Bentley Delivery Centre, Western Australia, Australia 6983) Email: dave.algar@dbca.wa.gov.au

 

 

More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves – UPDATE of EMR feature

Ian Davidson

[Update of EMR feature – Davidson, Ian and Peter O’Shannassy (2017) More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves. Ecological Management & Restoration, 18:1, 4-14.  https://onlinelibrary.wiley.com/doi/10.1111/emr.12247]

Roger Harris with direct seeded shrubs –  Rand TSR. (Photo Ian Davidson)

Introduction.  As described in our 2017 EMR feature, the Enriching biodiversity in the NSW Riverina project was a five-year project funded by the Federal Government’s Carbon Farming initiative and managed by Murray Local Land Services (LLS). The project aimed to maintain the condition of the highest quality TSRs and improve the condition of 10% of all other TSRs, some of which had been receiving degrees of grazing management for many decades to optimize resilient native pastures (Refer to our earlier 2005, EMR feature). Given the NSW Riverina TSR network contains over 600 reserves, a sample was first selected for inspection to identify reserves with the potential for further active management. This led to the implementation of recommended land management and works on 109 reserves covering 13,558 ha and the subsequent monitoring of those reserves. Results indicated that, of these reserves, 70 had improved in vegetation condition by 2017. This project proved that large scale protection and improvement of TSR condition was possible using existing staff and provided valuable lessons that could be applied elsewhere across the state.

Table 1 Summary of key lessons learnt from the project and recommendations for effective TSR management

Human resources ·       Use existing knowledge where available

·       Maintain continuity of leadership

Assessment and

monitoring

·       Establish broadly applicable and consistent assessment and monitoring criteria

·       Use methods which are easily understood

·       Consider seasonal effects on the timing of surveys

·       Recommended actions should be appropriate for the site condition

Project Scale ·       Larger project areas and longer project timelines increase the rate of success

·       Regular monitoring avoids major problems

Revegetation ·       Seed banks are vital to achieving large scale revegetation

·       Multiple species should be used in direct seeding

·       Exotic grasses should be controlled prior to direct seeding

·       Native species can assist in spreading shrubs over time

Land Management ·       Controlling herbivores is critical during early growth stages

·       Grazing indicators/surrogates are useful

·       Stock type impacts grazing style

·       Cattle can graze areas with shrub seedling germination under certain conditions

·       Fencing and water points offer flexibility in managing stock for regeneration

·       Noisy Miners reduce small woodland bird numbers and they are difficult to control

Unplanned Impacts ·       Human intervention in unpredictable Natural events can lead to major changes in land management focus

Stuart Watson monitoring vegetation at Narrow Plains TSR. (Photo Ian Davidson)

Subsequent developments. Since the publication of our 2017 feature ‘More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves’ the following five key developments regarding nature conservation on TSRs in NSW have occurred.

  1. Developing and applying a simple field based consistent method for assessing and monitoring vegetation condition across the TSR network – A new rapid assessment and monitoring method was developed and trialed in this project for use by land managers with limited botanical and scientific skills and limited time. This field-based method known as Rapid Conservation Assessment Method (RAM) proved useful and has the potential for broader adoption across NSW. For detailed information refer to https://www.lls.nsw.gov.au/livestock/stock-routes/conservation-of-tsrs
  2. Categorizing the conservation status using an agreed method of TSRs across NSW – Using the RAM to complete assessments and collating all previously assessed TSR reports, LLS developed a consistent statewide map of the conservation status for the 534,000ha under their control (refer to https://www.lls.nsw.gov.au/livestock/stock-routes/conservation-of-tsr). This enabled LLS, the statewide land manager, to better understand the overall vegetation condition, extent and distribution of their TSR assets from a nature conservation perspective.
  3. Developing a Best environmental management practice (BeMP) Toolkit for TSRs to ensure good long-term conservation objectives – Key knowledge learnt from the Riverina project, LLS ranger’s knowledge and experience and existing literature influenced the development of the NSW Travelling Stock Reserves State Planning Framework 2016–21 (the Framework), which provides the framework for managing TSRs for conservation. A Best Environmental Management Practice (BeMP) toolkit was also prepared from this collation of knowledge to assist LLS deliver land management outcomes (including grazing, apiary, native seed collection, emergency response/refuge for livestock, threatened ecological communities and species, revegetation on TSRs, weed control, pest animal control, soil disturbance and drainage changes) consistent with the Framework. The BeMP is currently in draft form.
  4. Developing a statewide plan of management (PoM) for TSRs to ensure consistency across administrative boundaries – The NSW government is finalizing the details of a PoM which provides LLS staff, TSR stakeholders, investors, partners and customers with our shared vision and common mission. It sets out agreed strategies, approaches, principles and quality system to better manage the reserves. This PoM aims to improve social, economic, environmental and cultural outcomes while maintaining grazing as an important economic use and conservation tool. Importantly this plan establishes the need for shared responsibility and collaborative funding. For more information refer to https://www.lls.nsw.gov.au/__data/assets/pdf_file/0005/839930/NOV-TSR-PoM-MOedits-1.pdf
  5. Attracting significant investment to assist with protection and maintenance of TSR environmental values – LLS the managers of NSW TSRs receive no recurrent funding from government for the environmental management of the TSR estate and therefore have been dependent upon the proceeds from permits and leases e.g. grazing and annual grants e.g. weed and pest animal control to maintain the condition of TSRs. Now however, based on the PoM and guided by environmental management and works consistent with best environmental management practice, the LLS is negotiating with a government investor to fund agreed long term maintenance and enhancement of selected high and moderate conservation value TSRs.

Peter O’Shannassy with direct seeded shrubs on Snake Island TSR. (Photo Ian Davidson)

Lessons learned. Together, the five developments above show how the large-scale restoration project reported in 2017 has been further developed as a model for TSR protection and restoration across NSW, enabling buy-in by LLS to better manage these invaluable natural resource assets across NSW.

Acknowledgements. LLS staff Peter O’Shannassy steered most aspects of the project from its inception, whilst Stuart Watson and Roger Harris managed most of the on-ground management and works and lately Gary Rodda the Murray General Manager who has overseen the statewide development of the PoM. Lastly, I dedicate my TSR work to my great mate Rick Webster who was lost to us recently and with whom I shared a deep, long standing curiosity and love of these special areas.

Contact.  Ian Davidson (for technical matters) ian@regenerationsolutions.com.au  or  Peter O’Shannassy  (for land management and operational matters) peter.o’shannassy@lls.nsw.gov.au

 

 

 

 

 

 

Butterfly population persists 10 years after emergency habitat restoration and translocation – UPDATE to EMR feature

[Update to 2008 EMR feature  –  Raymond Mjadwesch and Simon Nally (2008) Emergency relocation of a Purple Copper Butterfly colony during roadworks: Successes and lessons learned. Ecological Management & Restoration,  9:2, 100-109.   https://doi.org/10.1111/j.1442-8903.2008.00400.x]

By Simon Nally and Raymond Mjadwesch

Fig 1.  The endangered Purple Copper Butterfly (Paralucia spinifera) (Photo Raymond Mjadwesch)

Key wordsParalucia spinifera, Purple Copper Butterfly, reintroduction, invertebrate, threatened species.

Introduction: As reported in the original EMR feature, the unintended destruction of the habitat of a population of the endangered Purple Copper Butterfly (Paralucia spinifera, Fig 1) north of Lithgow, Australia in 2004, precipitated a bold, innovative, and rapid emergency program of habitat restoration and butterfly larvae translocation.

A stand of the butterfly’s larval host plants, Blackthorn (Bursaria spinosa subsp. lasiophylla), had been largely destroyed to enable road construction (Fig 2a). The butterflies had commenced emerging from their nearly nine-month-long pupation in the attendant ant’s (Anonychomyrma itinerans) underground nests to find an absence of host plants.

Construction work ceased immediately, and supplementary Blackthorn plants were planted throughout the area of predicted butterfly emergence. The Blackthorn were planted in their pots, to allow for later removal and replanting in the area where the habitat was being restored.  The Blackthorn were sugar-baited to attract the attendant ant as the ant was assumed to affect the male butterfly’s selection of home ranges, and ultimately, egg-laying on these larval host plants. Concurrently with the provision of Blackthorn for egg-laying, an adjoining degraded area of potential habitat was treated for infestations of woody weeds and growth of emergent Eucalyptus trees that excluded Blackthorn or blocked sunlight, precluding its suitability for occupation by the species.  Once weeds were controlled, Blackthorn was established in this area using tube-stock planting.

Attendant ants were enticed to all the Blackthorn introduced to the site, male butterflies established territories and were successful at attracting females with whom to mate, and these females laid eggs on the Blackthorn. The project partners were relieved at these initial results! However, as much of the site was to be permanently destroyed due to road construction, this temporarily reprieved population had to be translocated.

Over 12 nights, 1,260 of the facultatively nocturnal larvae were collected (along with any associated attendant ants) as they emerged to feed on Blackthorn leaves and translocated to the newly created habitat established on an adjacent restoration area (Fig 2b). Each translocated larva was monitored until it was attended by ants (again attracted to the recipient habitat using a sugar bait). Further monitoring continued to confirm continued growth of larvae until pupation was assumed to occur.

The duration of the emergency habitat restoration and translocation activities from first discovery of the habitat destruction to the assumed pupation of the translocated larvae in the newly established habitat (Fig 3) was less than five months.

After the autumn and winter pupation period, the project partners were delighted to find butterflies emerging, mating, and laying eggs on the remaining restored habitat, one year after the initial habitat destruction was first detected. Monitoring of larval numbers during 2005-2008, which involved systematic nocturnal inspection of all Blackthorn plants at the site, indicated that the population was secure and had grown after an initial reduction in calculated numbers in the first year after translocation.

Figure 2a. 2004 – The site as found showing the extent of habitat destruction (when the butterfly and habitat loss was initially detected). (Photo Raymond Mjadwesch)

Figure 2b. 2005 – Larvae from yellow-delineated area were translocated (after temporary introduction) into the blue-delineated area and bushland further right. (Photo Raymond Mjadwesch)

Monitoring update: In 2013 and 2015 monitoring reverted to an area search method, counting flying butterflies – a technique routinely used to indicate butterfly distribution / areas of activity at each of the other known populations. In 2015, ten years after the emergency translocation and habitat restoration, 48 butterflies were observed in the restored habitat, the second highest number recorded for this site.

Note that the results of monitoring counts can vary with date of survey relative to the flying period, time of day, and weather conditions on the day, and represent an indicator of presence and activity rather than a measure of absolute abundance. During some years multiple monitoring events occurred; in 2013 and 2015 there was only a single monitoring count.

There have been no further nocturnal larvae counts since the culmination of the project.

A 2019 site assessment identified the need for further woody weed maintenance works (which has been ongoing in the interim, funded by the LLS) to avoid potential degradation of the habitat quality due to competition with and shading of the host plant, Blackthorn.  Longer term maintenance of this site may require active management to ensure persistence of Blackthorn either through burning or mechanical damage to Blackthorn to promote re-sprouting from the rootstock and juvenile leaf production. Juvenile leaves lack the hairy indumentum present on the lower surfaces of intermediate and adult Blackthorn leaves, and have been observed to be preferentially skeletonized by early-instar larvae.

The 2019 site inspection also revealed that powerline easement works had resulted in weedicide spraying of eucalypt (Eucalyptus ssp.) saplings throughout the restored habitat, with Blackthorn plants and other native plant species affected.

Figure 3a – the site in 2005, after restoration works were complete, showing the initial flush of pioneer species after soil disturbance and restoration. (Photo Raymond Mjadwesch)

Figure 3b – the site in 2019 showing the final shrubby understory of sedges and shrubs (including scattered Blackthorn) typical of the locally native open forest community. (Photo Raymond Mjadwesch)

Lessons learned and future directions: Several factors contributed to the success of the habitat restoration and translocation program, some of which were of notable serendipity. It was extremely fortunate that the species was detected within the affected area (after the initial survey of the site had failed to detect habitat for the species); that Blackthorn tube-stock (upon which the restoration relied) was available; that an area considered likely to support Purple Copper Butterfly suitable for rehabilitation lay adjacent to the affected area; and that the timing of the damage in the annual lifecycle of the species allowed the partners to work with the opportunity to establish larval food plants  when it was required.

However, we believe that it was human factors that fundamentally combined to create the environment for success:

  • the commitment of the NSW Roads and Maritime Services (then the RTA) to immediately and fully support restoration works to ameliorate the damage and maximize the chances of the population surviving in the long term, including changing the design of the works to reduce the extent of permanent damage, and the funding of the restoration, translocation, and monitoring activities.
  • the project partners, including the authors, the RTA, NSW National Parks and Wildlife Service, Australian Trust for Conservation Volunteers, and Lithgow LandCare unified in collaboration, ceasing other activities to direct all necessary effort to maximize chances of success.
  • the quick, resourceful and bold action to trial and implement innovative techniques that were risky and speculative, such as luring attendant ants to planted Blackthorn using sugar, trial translocating attendant ants, and translocating larvae.
  • that there had been sufficient field observations to  predict the likely behavior of butterflies and larvae and to predict the likely response of the species’ habitat to management intervention.

We encourage restoration practitioners to immerse themselves in the environments they intend to manipulate, and ponder on the behavior, function, and interactions between each element of the ecosystem before them. When choosing to act – to intervene – to manipulate, do so sensitively to what you both know and feel that you have learned in the field, and act decisively, quickly, and boldly. Most importantly, corral a team of partners who believe in the endeavor and who fully commit their support to each other for a common restoration objective.

Endnote: In September 2019, an unplanned fire burnt much of the site. Given the monitoring data available for this site, further monitoring to study the effect of fire on the species and its habitat is being considered.

 Stakeholders and Funding bodies:   NSW Roads and Traffic Authority (now NSW Roads and Maritime), NSW National Parks and Wildlife Service (now NSW Office of Environment and Heritage), Australian Trust for Conservation Volunteers, Lithgow LandCare, Australian Government Department of Environment and Energy

Contact information: Simon Nally, 8 Gurney Place PAGE ACT, Australia, Tel: +61 407870234, Email: suseandsimon@bigpond.com. Ray Mjadwesch, Mjadwesch Environmental Service and Support, 26 Keppel Street, Bathurst, NSW 2795 Australia, Tel: +61 423949789, Email:  ray@mjadweschenvironmental.com.au

Ku-ring-gai Flying-fox Reserve Habitat Restoration Project at Gordon, 2000 – 2019 UPDATE of EMR feature

Nancy Pallin

[Update to EMR feature –  Pallin, Nancy (2001) Ku-ring-gai Flying-fox Reserve Habitat restoration project, 15 years on.  Ecological Management & Restoration 1:1, 10-20.  https://onlinelibrary.wiley.com/doi/10.1111/emr.12229]

Key words:         bush regeneration, community engagement, wallaby browsing, heat events, climate change

Figure 1. Habitat restoration areas at Ku-ring-gai Flying-fox Reserve within the urban area of Gordon, showing areas treated during the various phases of the project. Post-2000 works included follow up in all zones, the new acquisition area, the pile burn site, the ecological hot burn site and sites where vines have been targeted. (Map provided by Ku-ring-gai Council.)

Introduction. The aim of this habitat restoration project remains to provide self-perpetuating indigenous roosting habitat for Grey-headed Flying-fox (Pteropus poliocephalus) located at Ku-ring-gai Flying-fox Reserve in Gordon, NSW Australia (Fig 1).  The secondary aim was to retain the diversity of fauna and flora within the Flying-fox Reserve managed by Ku-ring-gai Council. Prior to works, weed vines and the activity of flying-foxes in the trees had damaged the canopy trees while dense weed beneath prevented germination and growth of replacement trees.  Without intervention the forest was unable to recover.  Natural regeneration was assisted by works carried out by Bushcare volunteers and Council’s contract bush regeneration team.  The work involved weed removal, pile burns and planting of additional canopy trees including Sydney Bluegum (Eucalyptus saligna), which was expected to cope better with the increased nutrients brought in by flying-foxes.

Figure 2. The changing extent of the Grey-headed Flying-fox camp from the start of the project, including updates since 2000. (Data provided by KBCS and Ku-ring-gai Council)

Significant changes have occurred for flying-foxes and in the Reserve in the last 20 years.

In 2001 Grey-headed Flying-fox was added to the threatened species lists, of both NSW and Commonwealth legislation, in the Vulnerable category.  Monthly monitoring of the number of flying-foxes occupying the Reserve  has continued monthly since 1994 and, along with mapping of the extent of the camp, is recorded on Ku-ring-gai Council’s Geographical Information System. Quarterly population estimates contribute to the National Monitoring Program to estimate the population of Grey-headed Flying-fox.  In terms of results of the monitoring, the trend in the fly-out counts at Gordon shows a slight decline.  Since the extreme weather event in 2010, more camps have formed in the Sydney basin in response to declining food resources.

In 2007, prompted by Ku-ring-gai Bat Conservation Society (KBCS), the size of the Reserve was increased by 4.3 ha by NSW Government acquisition and transfer to Council of privately owned bushland. The Voluntary Conservation Agreement that had previously established over the whole reserve in 1998 was then extended to cover the new area.   These conservation measures have avoided new development projecting into the valley.

From 2009 Grey-headed Flying-fox again shifted their camp northwards into a narrow gully between houses (Fig 2).  This led to human-wildlife conflict over noise and smell especially during the mating season. Council responded by updating the Reserve Management Plan to increase focus on the needs of adjoining residents.  Council removed and trimmed some trees which were very close to houses. In 2018 the NSW Government, through Local Governments, provided grants for home retrofitting such as double glazing, to help residents live more comfortably near flying-fox camps.

Heat stress has caused flying-fox deaths in the Reserve on five days since 2002. Deaths (358) recorded in 2013, almost all were juveniles of that year.  KBCS installed a weather station (Davis Instruments Vantage Pro Plus, connected through a Davis Vantage Connect 3G system) and data loggers to provide continuous recording of temperature and humidity within the camp and along Stoney Creek.  The station updates every 15 minutes and gives accurate information on conditions actually being experienced in the camp by the flying-foxes. The data is publicly available http://sydneybats.org.au/ku-ring-gai-flying-fox-reserve/weather-in-the-reserve/Following advice on the location and area of flying-fox roosting habitat and refuge areas on days of extremely high temperatures (Fig 3.) by specialist biologist Dr Peggy Eby, Council adopted the Ku-ring-gai Flying-fox Reserve 10 Year Management and Roosting Habitat Plan in 2018.  Restoration efforts are now focused on improving habitat along the lower valley slopes to encourage flying-foxes to move away from residential property and to increase their resilience to heat events which are predicted to increase with climate change.

Figure 3. Map showing the general distribution of flying-foxes during heat events, as well as the location of exclosures. (Map provided by Ku-ring-gai Council)

Further works undertaken.  By 2000 native ground covers and shrubs were replacing the weeds that had been removed by the regeneration teams and Bushcare volunteers.  However, from 2004, browsing by the Swamp Wallaby (Wallabia bicolor) was preventing growth of young trees and shrubs.  Bushcare volunteers, supported by KBCS and Council responded by building tree cages made from plastic-mesh and wooden stakes. Reinforcing-steel rods replaced wooden stakes in 2008.   From 2011, the Bushcare volunteers experimented with building wallaby exclosures, to allow patches of shrubs and groundcovers to recover between trees (Figs 3 and 4).  Nineteen wallaby exclosures have been built. These range in size from 7m2 to 225m2 with a total area of 846m2.   Wire fencing panels (Mallee Mesh Sapling Guard 1200 x 1500mm) replaced plastic mesh in 2018.  Silt fence is used on the lower 0.5m to prevent reptiles being trapped and horizontally to deter Brush Turkey (‎Alectura lathami) from digging under the fence.

The wallaby exclosures have also provided an opportunity to improve moisture retention at ground level to help protect the Grey-headed Flying-fox during heat events.  While weed is controlled in the exclosures south of Stoney Creek, those north of the creek retain Trad and privets, consistent with the 10 Year Management and Roosting Habitat Plan.

Madeira Vine (Anredera cordifolia) remained a threat to canopy trees along Stoney Creek for some years after 2000, despite early treatments.  The contract bush regen team employed sInce 2010 targeted 21 Madiera Vine incursions.

A very hot ecological burn was undertaken in 2017 by Council in order to stimulate germination of soil stored seed and regenerate the Plant Community Type (PCT) – Smooth-barked Apple-Turpentine-Blackbutt tall open forest on enriched sandstone slopes and gullies of the Sydney region (PCT 1841).  This area was subsequently fenced. The contract bush regeneration team was also employed for this work to maintain and monitor the regeneration in the eco-burn area (720 hours per year for both the fire and Madiera Vine combined).

Figure 4. Exclusion fence construction method. Pictured are Bushcare volunteers, Jill Green and Pierre Vignal. (Photo N Pallin).

Figure 5. Natural regeneration in 2018 in (unburnt) exclosure S-6 (including germination of Turpentines). (Photo N. Pallin)

Further results to date. The original canopy trees in Phase 1 and Phase 2 (1987 -1997) areas have recovered and canopy gaps are now mostly closed. Circumference at breast height measurements were taken for seven planted Sydney Blue gum trees.  These ranged from 710 to 1410mm with estimated canopy spread from 2 to 6m.  While original Turpentine (Syncarpia glomulifera) had circumferences from 1070 and 2350mm with canopy spread estimated between 5and 8m, those planted or naturally germinated now have circumference measurements between 420 and 980mm with canopy spread estimated from 1.5 to 3m.  A Red Ash (Alphitonia excelsa) which naturally germinated after initial clearing of weeds now has a circumference of 1250mm with a canopy spread of 5m.  Also three Pigeonberry Ash (Elaeocarpus kirtonii) have circumference from 265 to 405mm with small canopies of 1 to 2m as they are under the canopies of large, old Turpentines.  As predicted by Robin Buchanan in 1985 few Blackbutt (Eucalyptus pilularis) juveniles survived while the original large old trees have recovered and the Sydney Bluegum trees have thrived.

In the Phase 3 (1998 – 2000) area south of Stoney Creek the planted Sydney Blue Gum now have circumferences measuring between 368 and 743 (n7) with canopy spread between 2 and 6 m.  in this area the original large trees have girths between 1125 and 1770mm (n7) whereas trees which either germinated naturally or were planted now range from 130 to 678mm (n12).  These measurement samples show that it takes many decades for trees to reach their full size and be able to support a flying-fox camp.

Wallaby exclosures constructed since 2013 south of Stoney Creek contain both planted and regenerated species.  Eight tree species, 11 midstorey species, 27 understorey species and eight vines have naturally regenerated.  Turpentines grew slowly, reaching 1.5m in 4 years.  Blackbutts thrived initially but have since died. In exclosures north of the creek,  weeds including Large-leaved Privet,  Ligustrum lucidum,  Small-leaved privet,  L. sinense,  Lantana, Lantana camara,  and Trad, Tradescantia fluminensis) have been allow to persist and develop to maximise ground moisture levels for flying-foxes during heat events. Outside the exclosures, as wallabies have grazed and browsed natives, the forest has gradually lost its lower structural layers, a difference very evident in Fig 6.

Figure 6. Visible difference in density and height of ground cover north and south of Stoney creek. (Photo P. Vignal)

Coachwood (Ceratopetalum apetalum) were densely planted in a 3 x 15m exclosure under the canopies of mature Coachwood next to Stoney Creek in 2015. In 4 years they have reached 1.5m.  In this moist site native groundcovers are developing a dense, moist ground cover.

Madiera Vine, the highest-threat weed, is now largely confined to degraded edges of the reserve, where strategic consolidation is being implemented with a view to total eradication.

In the hot burn area, which was both fenced and weeded, recruitment has been outstanding. One 20 x 20m quadrat recorded 58 native species regenerating where previously 16 main weed species and only 6 native species were present above ground. A total of 20 saplings and 43 seedlings of canopy species including Eucalyptus spp., Turpentine and Coachwood were recorded in this quadrat where the treatment involved weed removal, burning and fencing  (S. Brown, Ku-ring-gai Council, July 2019, unpublished data).  Unfortunately, however, the timing and location of the burn did not take into account its impact on the flying-fox camp and there was some damage to existing canopy trees. It will be many years before the canopy trees, which are regenerating, will be strong enough to support flying-foxes.

Monitoring from the weather station and data loggers has shown that close to Stoney Creek on a hot day it is typically 2-3° C cooler, and 5-10% higher in humidity, than in the current camp area (pers. comm. Tim Pearson). During heat events the flying-foxes move to this cooler and moister zone, increasing their chances of survival.

Fauna observed other than flying-foxes includes a pair of Wedge-tail Eagle ( Aquila audax plus their juvenile, a nesting Grey Goshawk (Accipiter novaehollandiae) and a Pacific Baza (Aviceda subcristata).  Powerful Owl (Ninox strenua) individuals continue to use the valley. The presence of raptors and owls indicate that the ecosystem processes appear to be functional. Despite the decline of the shrub layer outside fenced areas, the same range of small bird species (as seen prior to 2000) are still seen including migrants such as Rufous Fantail ( Rhipidura rufifrons) which prefers dense, shady vegetation. The first sighting of a Noisy Pitta (Pitta versicolor) was in 2014.  Long-nosed Bandicoot (Perameles nasuta) individuals appear and disappear, while Swamp Wallaby remains plentiful.

Lessons learned and future directions. Climate change is an increasing threat to Pteropus species. On the advice of Dr Eby, Flying-fox Consultant, Council, KBCS and Bushcare Volunteers agreed to retain all vegetation including weeds such as Large-leaved Privet and Small-leaved Privet, patches of the shrub Ochna (Ochna serrulata) and Trad as a moist ground cover in the camp area and areas used by the flying-foxes during heat events.

Building cheap, lightweight fencing can be effective against wallaby impacts, provided it is regularly inspected and repaired after damage caused by falling branches. This style of fencing has the additional advantage of being removable and reusable.  It has been proposed that, to provide understory vegetation to fuel future burns in parts of the reserve away from the flying-fox camp, further such temporary fencing could be installed.

Ku-ring-gai Council has commenced a  program to install permanent monitoring points to annually record changes in the vegetation, consistent with the state-based  Biodiversity Assessment Method.

Stakeholders and Funding bodies. Members of KBCS make donations, volunteer for monthly flyout counts, Bushcare and present educational events with live flying-foxes. KBCS hosts the website www.sydneybats.org.au. Ku-ring-gai Council which is responsible for the Reserve has been active in improving management to benefit both residents and flying-foxes.  Ku-ring-gai Environmental Levy Grants to KBCS have contributed substantially to purchase of fencing materials and the weather station. http://www.kmc.nsw.gov.au/About_Ku-ring-gai/Land_and_surrounds/Local_wildlife/Native_species_profiles/Grey-headed_flying-fox

Thank you to Jacob Sife and Chelsea Hankin at Ku-ring-gai Council for preparing the maps and to volunteer Pierre Vignal for assistance with tree measurements, downloading data loggers and a photo.  Researcher,  Tim Pearson installed the weather station.

Contact information. Nancy Pallin, Management Committee member, Ku-ring-gai Bat Conservation Society Inc.  PO Box 607, Gordon 2072  Tel 61 418748109. Email:  pallinnancy@gmail.com

Is revegetation in the Sheep Pen Creek area, Victoria, improving Grey-crowned Babbler habitat? – UPDATE of EMR feature

Doug Robinson

[Update of EMR feature Robinson, Doug (2006) Is revegetation in the Sheep Pen Creek area, Victoria, improving Grey‐crowned Babbler habitat?  Ecological Management & Restoration, 7:2, 93-104.  https://doi.org/10.1111/j.1442-8903.2006.00263.x]

Key words: (<5 words): Monitoring, restoration, population ecology, woodland conservation

Figure 1. Location of babbler project works and other landcare works implemented since 1996 in the Sheep Pen Creek Land Management Group area and the two sub-districts used for the babbler study. (Source TFNVic)

Introduction: The Grey-crowned Babbler (Pomatostomus temporalis) (babbler) is a threatened woodland bird (classified as Endangered in the state of Victoria) that has declined substantially in overall distribution and abundance across much of its former range in southeastern Australia since European settlement.  Sheep Pen Creek Land Management Group area, in northern Victoria (Fig 1), was fortuitously the location of the largest known remaining babbler population in Victoria in the early 1990s (when this project began); and the focus of extensive land restoration programs from the 1980s onwards to help mitigate the impacts of erosion and dryland salinity, as well as biodiversity decline.  The original study, published in 2006, investigated the overall changes in tree cover across the district between 1971 and 1996 as a result of different land-management actions and responses of local babbler populations to those habitat changes.  The key finding was that in the Koonda sub-district which had a 5% overall increase in tree cover to 14% from 1971 to 2001, showed an increase in babbler numbers by about 30% (Table 1).   In the Tamleugh sub-district, tree cover increased by 1.3% to a total of 9%, with no change in babbler numbers.  The findings also showed that new babbler groups were preferentially colonizing new patches of vegetation established that suited their habitat needs.  Building on this research, the study concluded that future conservation programs needed to scale-up the extent of habitat restoration, target areas which were suitable for babbler colonization, and tailor incentive programs to assist with conservation of particular species.

Table 1. Changes in Grey-crowned Babbler numbers over time

Year Koonda Tamleugh
number of groups number of birds number of groups number of birds
1992 20 78 11 39
1993 20 89 10 34
1996 24 96 9 35
1997 24 102 8 30
1998 25 99 10 40
2000 26 97 10 43
2005 23 99 8 34

Further revegetation works undertaken. Since the initial study’s assessment of vegetation changes between 1971 and 1996, an additional 133 ha of vegetation has been restored or established as babbler habitat in Koonda district and 37 ha in the Tamleugh district (Figs 2 and 3, Table 2).  Extensive natural regeneration, supplemented by broadscale revegetation, has also occurred over more than 350 ha on five private conservation properties in the Koonda district,, contributing to substantial landscape change.  The wider landscape has also been identified as a statewide priority for nature conservation on private land, leading to increased conservation investment in permanent protection there by Victoria’s lead covenanting body – Trust for Nature.

Monitoring of outcomes: The monitoring that was carried out prior to the 2006 publication has not continued, leaving a knowledge gap as to how the population has fared in the context of the Millenium Drought and ongoing climate-change impacts. However, based on the original research’s initial findings, we conducted an experimental study with University of Melbourne to evaluate the effectiveness of habitat restoration in maintaining babbler survival. The study, published by Vesk and colleagues in 2015, compared the persistence and group size of babbler groups present in 1995 and subsequently in 2008 at a randomly selected set of stratified sites which had either had habitat works or none.  This study was conducted across a larger landscape of about 200,000 hectares which included Sheep Pen Creek Land Management Group area.  The study found that babbler group size decreased by about 15% over the 13 years at sites without restoration works.   At sites with restoration, average group size increased by about 22%, thereby effectively compensating for the overall reduction in numbers reported over that time.This increase also influenced subsequent demographic performance, with groups at restoration sites having higher breeding success and more fledglings than groups at control sites.

Another useful finding from this experimental study was the confirmation of the importance of particular habitat and landscape variables on babbler persistence.  In particular, abundance of large trees was a positive predictor of occupancy over time; and distance from the next nearest group was a negative predictor.

Figure 2. Changes in tree cover in the Koonda sub-district between 1971 (top),  and 2018 (bottom). (Source TFNVic).. (Source TFNVic)

Figure 3. Changes in tree cover in the Tamleugh sub-district between 1971 (top) and 2018 (bottom). (Source TFNVic)

Table 2.  Summary of additional habitat established or restored as part of the Sheep Pen Creek Grey-crowned Babbler project from 1996-2018, following the initial study period from 1971-1996.

District Number of sites Area (ha)
Koonda 62 133
Tamleugh 28   37
Other parts of landcare group and local babbler population area 29 103
Totals 119 273

Expansion of lessons to other districts: Building on the fundamental research conducted in Sheep Pen Creek Land Management Group area, similar habitat, landscape and babbler population assessments were subsequently undertaken in northwest Victoria near Kerang for the babbler populations found there.  Key results from these studies relevant to the initial Sheep Pen study were that the number of babbler groups in each sampled district was positively related to the proportion of woodland cover, especially the proportion of Black Box (Eucalyptus largiflorens) woodland habitat – the babblers’ preferred habitat in this region.  Conversely, the number of babbler groups was negatively associated with the proportion of land under intensive agriculture.  At the site scale, key positive predictors of babbler presence in Black Box habitat again included the abundance of large trees (> 60 cm dbh)

Lessons learned and future directions: The most valuable lesson learned since the initial paper was published was the power of the structured research project described above to evaluate the effectiveness of the babbler conservation program and inform future design and planning. The study further demonstrated the importance of taking a demographic approach to the species’ conservation needs, understanding what is happening across the whole population over time  and how habitat interventions can assist.  These lessons have since been applied usefully to other babbler projects  and more broadly to conservation of woodland birds.

The initial paper noted the importance of achieving landscape-scale change in vegetation extent, particularly in more fertile habitats. This has occurred to some extent within the Koonda district through a range of incentive programs, tender programs, covenanting programs and land purchase, but continues to achieve most gains on more infertile land. On fertile land, by contrast, there has been rapid land-use change to cropping over the past fifteen years, leading to reduced likelihood of those properties providing suitable habitat for babblers, as found in the study conducted in northwest Victoria.

The initial paper also suggested the benefit of developing tailored incentive programs for babblers and other threatened species with particular requirements to maximize potential conservation gains  and we suggest, based on Australian and overseas experiences,  that more specific incentive programs or more detailed criteria could assist.

Another important lesson learned was the difficulty in maintaining community-driven citizen-science monitoring, even with the best will in the world, without some over-arching organizational support and oversight.  We know that community monitoring for biodiversity conservation needs scientific input at the design and analysis stages; hence additional resources may also be required in terms of equipment or guidelines to help groups monitor effectively.  Modest government investments to conservation organisations with established biodiversity monitoring programs could usefully help address this issue.

Finally, the learnings from the Sheep Pen Creek Land Management babbler conservation project over nearly thirty years are that the landscape changes and that these changes are not always positive.  Land-use change is placing more pressure on  potential babbler habitat; and the eucalypt regrowth which was established and provided new nesting resources for a few years is now too tall to provide nesting habitat, but too dense and immature to provide suitable foraging habitat for another one hundred years.  Climate change is rapidly imposing constraints on the availability of food resources and breeding opportunities, exacerbated by increased competition for the same limited resources by exotic and native species.  For the Grey-crowned Babbler, the solution to all of these factors depends on ongoing commitment to the establishment or maintenance of their essential habitat needs and life-history requirements so that their life-cycle is provisioned for from generation to generation.

Stakeholders and Funding bodies:   Most of the targeted habitat works achieved for babblers in this landscape has occurred through funding support from the Australian government through its Natural Heritage Trust and Caring for our Country programs.  Broader habitat protection and restoration has occurred primarily with funding support to landholders from the Goulburn Broken Catchment Management Authority (GBCMA).  The Norman Wettenhall Foundation, along with GBCMA, was instrumental in enabling the research by University of Melbourne, which was also aided by the extensive voluntary support of Friends of the Grey-crowned Babbler.  Not least, local landholders continued to support the project and continue to protect or restore parts of their properties to assist with babbler conservation.

Contact information: [Doug Robinson, Trust for Nature, 5/379 Collins Street Melbourne, Victoria 3000, Australia.  dougr@tfn.org.au, (03) 86315800 or 0408512441; and  School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.

 

 

 

 

Ecological restoration and rehabilitation at Sydney Olympic Park – UPDATE to EMR feature

Jennifer O’Meara and Kerry Darcovich

[Update to EMR feature – O’Meara, Jennifer and Kerry Darcovich (2015) Twelve years on: Ecological restoration and rehabilitation at Sydney Olympic Park, Ecological Management & Restoration, 16:1, 14-28. https://onlinelibrary.wiley.com/doi/10.1111/emr.12150 ]

Keywords: Environmental management, ecological management, threatened species, Habitat management , woodland birds, Green and Golden Bell Frog

Introduction. The 2015 EMR feature described ecological restoration and management works at Sydney Olympic Park, a large urban park containing both remnant and constructed landscapes that underwent significant restoration in preparation for the 2000 Olympic Games. Sydney Olympic Park supports a rich natural environment that includes over 250 native animal species, over 400 native plant species and three endangered ecological communities.  The high ecological values of the Park have resulted in 304 hectares (nearly half of the Park) being zoned under NSW planning legislation for environmental conservation and management.  Key habitats include estuarine and freshwater wetlands, remnant eucalypt forest, saltmarsh meadows and woodland bird habitats.

The Park’s biodiversity is of high conservation significance, and makes a significant contribution to the social and economic values of the Park.  The Park’s natural environments enrich visitor experience, provide a living classroom for environmental education programs, and attract businesses and residents seeking proximity to nature. This project began in 2000 when management transferred from a construction phase after the Sydney Olympic Games to an active management phase and is supported by an extensive long term ecological monitoring program. This update summarises new works and outcomes since 2016.

Further works undertaken. The introduction of new ecological infrastructure for frog habitat targets threatening processes of predation by introduced fish and increasing water availability.  Fish-proof fences have been introduced to wetlands where the predatory fish Gambusia (Gambusia holbrooki) is present in Green and Golden Bell Frog (Litoria aurea) habitat (Fig 1). The fences are placed around ponds or pond clusters and then the pond is dried out and refilled with fish-free water. Constructed of sediment fences 600mm high and embedded in the ground, these fences stretch to a maximum of 200m and have successfully restricted the fish from ponds for more than three years.

Figure 1.  Gambusia fence

In order to reduce the impact of bird predation on tadpoles in key breeding ponds, bird netting secured by wire cables to the ground and supported by hoops has been introduced.  The netting is also used as a response to the sighting of Green and Golden Bell Frog tadpoles in ponds with Sydney Olympic Park staff deploying temporary netting where successful breeding has occurred. Netting is left on the pond until all metamorphs have dispersed from the pond then removed.

Restoration of the water-holding capacity and connectivity of bell frog habitat in the Brickpit and Kronos Hill has been improved with temporary ponds being created with tarps (Fig 2). The aim is twofold – to extend the number of predator-free, drought refuges, important for adult female frogs and metamorphs and to ensure frog corridors maintain connectivity.  More than 10 tarp ponds have been created and have an expected life span of 3-6 years and are very budget friendly. Annual monitoring has shown a remarkable uptake of these ponds by the Green and Golden Bell Frog.

Figure 2.  Tarp pond with netting

Further results to date. The Parks ecological monitoring program is ongoing and now entering the 16th consecutive year for birds, 15th for reptiles and 21 years for the Green and Golden Bell Frog. In 2018-19 the fourth woodland bird survey was completed, a four yearly assessment of the status of woodland birds and vegetation management at Sydney Olympic Park. Fifteen quadrats are surveyed over the spring and autumn seasons to measure bird communities which is then compared to change in vegetation structure. Results show that small birds were strongly, positively correlated with shrub cover, but strongly negatively correlated with tree cover and Noisy Miner (Manorina melanocephala).  Since 2006, Sydney Olympic Park Authority has implemented a habitat modification program aimed at increasing the structural diversity and complexity of key areas of the Park to support woodland birds. The program seeks to build connectivity between key woodland bird habitats with the form of habitat enhancement varying depending on site characteristics. The survey shows that this program is successfully creating suitable habitat for this group of birds.

With the prospect of greater demands by the public to access the Park at all hours (see below), Sydney Olympic Park staff have recently collected baseline light level readings from across the Park to inform decision making.  Data on lux levels and light source was collected from over 160 sites ranging from car parks to mangrove creeks. The main drive of the survey was to collect information on light spill into sensitive habitat areas where darkness is a key ecological feature. The survey led to a review of lighting and identification of where lights could be switched off or timed to decrease light impacts. The findings will also inform future planning for illumination within the Park.

Lessons learned and future directions. Sydney Olympic Park is part of a rapidly densifying area with the 30,000 residents currently located within a 3km radius forecast to increase to approximately 100,000 in ten years. Due to the density of housing, Sydney Olympic Park will be/is already the local park for this community, leading to increasing demand for recreation and access to the Parklands. This presents great opportunities for more people to connect with nature and to incorporate community education and sustainability into Park programs.  A new program known as Park Care has been launched recently and currently rolls out community clean up and revegetation activities.

The flipside of this rapid population increase is increasing risk of disturbance to ecologically sensitive areas which needs to be considered and mitigated carefully as the Park continues to evolve. Ensuring the Park is able to sustainably meet this demand is a focus for management now and into the future. New habitat management plans for ecologically sensitive areas of the Park are being developed to better-guide biodiversity conservation on a precinct level. Ongoing ecological management works, and managing the impacts of human disturbance, will be essential to conserving the ecological values of the Park.

Contact. Jennifer O’Meara, Parklands Ecologist, Sydney Olympic Park Authority, 5 Olympic Boulevard, Sydney Olympic Park 2127 NSW, Australia. Email: Jenny.omeara@sopa.nsw.gov.au