Koalas and Sutherland Shire wildlife corridors

Koala spotted in Engadine, July 2020 – photo credit Brian Everingham

Koalas have been seen around the Sutherland Shire over the last couple of years at Sandy Point, Gymea, Engadine, in the Royal and Heathcote National Parks, and surrounding bushland. 

It’s wonderful we have koalas in and around Sutherland Shire, and exciting. We also need to take care they are protected. In 2022 koalas were formally listed as Endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act. This follows a report in 2020 from the NSW Legislative Council inquiry Koala populations and habitat in New South Wales which found koalas could become extinct in NSW by 2050 without urgent government intervention. 

That report recommended State government ‘urgently prioritise the protection of koala habitat and corridors in the planning and implementation stages of urban growth areas’.  It notes that wildlife corridors ensure ‘safe connectivity between habitat areas’ and are ‘essential for the survival of koalas.’ They allow animals to move freely over the landscape, find mates, build genetic diversity, escape difficult conditions, and maintain populations at viable levels.

Sadly quite a few koalas have been killed on the roads around the Shire. Heathcote Rd is a notorious kill zone. Unfortunately important wildlife corridors between our national parks are blocked too – the Princes Highway and the F6 act as 30-40m wide barriers.  The South Coast train line adds another 25m to that distance.

Reproduced from Mosley: The First National Park, with the inclusion of a new, potential overpass site near Loftus.

Wildlife corridors are recognised as critical to the survival of many native species, and the National Parks and Wildlife Service have known about the wildlife corridors shown in the image to the right for decades.

Despite this, these corridors are blocked by barriers preventing the free movement of native animals between these zones. Does it have to be this way? A number of underpasses and overpasses between national parks have been incorporated as part of the Mona Vale Road upgrade, so there are local Sydney precedents. It’s reasonable to expect such measures would be put in place to protect the biodiversity of Australia’s first national park, and we’ve stressed this point in our submission to the draft plan of management for the Garawarra State Conservation Area, Royal and Heathcote National parks.

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Information on this page covers some of the areas of concern around the Shire, and we held recently held a webinar if you’re keen to find out more.

The animals using crossings depicted in the image above are from a study by Associate Professor Ross Goldingay. The crossing shown in the image above is an overpass linking Garigal and Ku-ringai National Parks at Mona Vale Road West

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Koala sightings near the Shire to 24 March, 2022 – www.bionet.nsw.gov.au

Wildlife corridors are not just needed between our parks, but also to prevent koalas from being killed on other roads. The little red triangles in this diagram are koalas that have been seen around the Shire. It’s wonderful that there are so many. Unfortunately the sightings on roads are often koalas that have been hit by cars; and injured or killed.

Over the last year we’ve put in submissions to Sutherland and Wollongong council, have written to State MPs, met with representatives from State government agencies, including the NSW Koala Strategy team and TransportNSW. We’ve also been liaising with a number of other local environmental groups, working together and asking the government to take action.

We’re hoping that as as a result of this advocacy underpasses will be put in at Deadmans Creek at Sandy Point, and at Heathcote Road Bridge when the bridge widening project there begins. More on this below, why wildlife crossings are needed at these locations.

Photo credit WIRES: “Wonnie” the koala, rescued from bushland at Woronora, September, 2021.

It is grim and disappointing that government agencies seem to take so long to do anything when koalas continue to be killed on our roads.

The fate of the Campbelltown and Appin koalas also appears particularly dire. The Greater MacArthur Growth Plan proposes to replace prime koala habitat with over 40,000 new homesites.

There are hundreds of healthy koalas in that location. It is not clear if they will survive development of the magnitude of what is proposed. The Save Sydney’s Koalas group have been working with the Total Environment Centre to advocate for this colony, asking the Ministers for Planning and Environment and the local council, to take action to protect habitat, and ensure sufficiently wide corridors connect the Georges and Nepean Rivers.  

At the end of the day, whether or not koalas become extinct by 2050 will be a political choice.

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The following section provides more detail about zones where koalas protections could be put in place in the Sutherland Shire, and down to Helensburgh. 

Four main locations are identified, including a number of “kill zones” along Heathcote Road:  

1. protective measures could be put in place at the Deadman’s Creek kill zone at Sandy Point;

2. around the Lucas Heights precinct;

3. around Heathcote Road Bridge over the Woronora River; and,

4. Cawley’s Bridge near Helensburgh crosses the F6 Freeway at Garawarra: it is not used as a public road, but remains a service road for various agencies. This bridge could be easily be transformed to offer a critical wildlife corridor allowing native animals safe passage from Heathcote National Park and the Woronora Special Area catchment through to the Garawarra State Conservation Area and on to the Royal National Park.

Ideally the NSW government would be encouraging National Parks management to investigate the feasibility of developing wildlife crossings at a range of locations.

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Recent Bionet records of koalas killed and observed around Heathcote and Waterfall on F6 and surrounding roads

Proposed repurposing of Cawley’s Bridge at Garrawarra as a wildlife corridor over the F6 Freeway

Cawley’s bridge can potentially allow native animals safe passage over the F6 from Heathcote National Park and the Woronora Special Area catchment through to the Garawarra State Conservation Area and on to the Royal National Park.  The Royal National Park has become increasingly isolated from surrounding natural lands. Some species originally found in the Park are now locally extinct.

Repurposing Cawley’s bridge into a wildlife overpass can be done for relatively minimal cost.  One lane of the service road could be retained: it may only be necessary to convert one side of the bridge into suitable wildlife habitat crossing.  Sheltered walkways could be built on the bridge rails for the use of arboreal species and connected to nearby trees to allow wildlife to safely access the crossing.

At Cawley’s Bridge – with a bird’s eye view of the great division of the natural landscape and obstacle to wildlife movement presented by the F6 freeway

Cawley’s Road bridge view looking south from the bridge
Cawley’s road bridge viewed from the east side

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The Compton Road overpass in South-East Queensland provides evidence that Cawley’s bridge could be successfully transformed in this manner.

Compton Road is a major east-west arterial road similar to the F6.  In the 10 years since the completion of the land bridge there, only 3 mammals have been killed from motor vehicle accidents. Before this, 5 were killed on this road every month.

Compton Rd rope ladders

The overpass at Compton Road is planted with locally sourced vegetation making a seamless connection to the surrounding forest. It features rope ladders for possums, poles for gliders and customised culverts to act as tunnels for small animals to pass beneath the road.

Rope ladders are important for arboreal animals such as gliders. Greater Gliders were thought locally extinct in the Royal National Park following the horrific 1994 bushfires. The wonderful news is that they have recently been seen again, so there’s now been at least three sightings over the last ten years. The population may still be too small to survive, but at least we have hope. Anything that could be done to sustain the population and build genetic diversity would be valuable.

With Compton Road, another important component of the wildlife crossing is adjacent fencing which funnels wildlife towards the safe crossings, away from busy roads.

This customised fencing is 2.48m, much higher than regular road fencing. This stops animals such as wallabies and kangaroos from gaining easy access. Metal sheet strips deter climbing animals such as koalas and possums. The project has apparently been used to guide best practice designs at a number of major road construction approvals across Australia, and is now industry standard for roads incorporating wildlife management measures.

The Compton Road overpass is a model for what can be achieved with wildlife overpass crossings and has been duplicated across Europe, with seven overpasses in Sweden alone.

In addition to Cawley’s bridge these measures would also be easy to implement along Heathcote Road at Sandy Point, the Lucas Heights Precinct, and Woronora Bridge with the forthcoming upgrades there.

See this Gardening Australia YouTube video ▼ for an overview of the Compton Road overpass – and what could be possible at Cawley’s bridge across the F6

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There is one further site at Loftus between houses that could potentially offer another crossing location over the F6 from the Royal National Park to bushland through to Loftus Creek and Woronora.  

As we pointed out in a recent submission opposing the subdivision of land owned by Sydney Water at Woronora Heights, this whole area is a wildlife corridor, and is used by koalas.

This corridor leads from the Woronora River through to Loftus. At Loftus there is a potential site for a future wildlife crossing. We flagged this spot in our submission to the Royal National Park draft plan of management. 

It would be wonderful to link this landscape which was artificially divided when the freeway was put in.

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Sandy Point – the Deadman’s Creek kill zone

The Deadman’s Creek kill zone

A significant number of koalas have been killed at Deadman’s Creek at Sandy Point, with confirmed reports of at least 6 koalas killed in 2018 alone. An underpass already exists at a bridge at Sandy Point which could be modified to allow safe passage for these koalas. 

As with Compton Road, directional fencing could be installed to act as a funnel directing wildlife towards this underpass.  Rope ladders for possums and poles for gliders could be installed overhead.  Local Aboriginal land holders to the east of the road and the Ministry of Defence on the western side would need to be consulted in order to obtain permission for proper fencing to be installed. The Department of Roads and Sutherland Shire Council would also need to approve this work.

TransportNSW have commissioned a report into mitigation measures here and we hope this will be released shortly.

A Sandy Point resident spotted this koala mother and baby on the road in September 2020. These two survived the crossing but there were two other koalas killed at Deadmans Creek that month.

The Holsworthy military training base was devastated by fire in 2018.  Clear-felling of koala habitat at the Moorebank Intermodal Site and the relocation of the new Army Logistics site on Moorebank Rd has further jeopardised koala habitat around the area, forcing them to seek alternative food sources. 

The Appin, Mt Gilead and Wilton areas appear to be increasingly subject to urban expansion.  Meanwhile the recent parliamentary inquiry report recommended the government ‘urgently prioritise the protection of koala habitat and corridors in the planning and implementation stages of urban growth areas’. 

Heathcote Rd. Photo credit: Jason Luke

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Lucas Heights and Heathcote Road bridge at Woronora River

Koalas have also unfortunately been killed around New Illawarra Rd near ANSTO and along the nearby section of Heathcote Road. And sighted and killed on Heathcote Road near the bridge over Woronora River.

We have put in a submission to TransportNSW about possible mitigation measures with the Heathcote Road Bridge widening project.

This upgrade offers an ideal time to install koala friendly wildlife crossing and fencing.  These measures could, theoretically, also be implemented at ANSTO’s Lucas Heights Innovation Precinct.

Koalas regularly attempt to cross over roads here, and get hit by cars. The diagram to the right shows where koalas have been sighted in the area, and the diagram under that likely routes along creek lines which koalas are taking to move around the landscape near Heathcote and New Illawarra Roads toward Engadine and the Woronora River.

The Heathcote Road bridge at Woronora

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The devastating fires over the last year have wreaked a terrible toll on our native animal populations; in relation to koalas specifically the NSW Legislative Council inquiry has advised government urgently needs to assist in protecting remaining populations in order to conserve habitat. 

Engadine koala, April 2021. Photo credit: Sharon Redman

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For more information, or to help with this campaign please contact Dr Catherine Reynolds

catherine@ssec.org.au or 0424 644 144

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If you see a koala please be sure to report him / her on the I Spy Koala app.

Government agencies make decisions based on the numbers of koalas that are reported.

* Please let your friends know we need to report every sighting.

Further reading

The NSW Government Puts South West Sydney Koalas on Pathway to Extinction

2 September, 2022, Merrill Witt, “The NSW Government puts South West Sydney koalas on pathway to extinctionNew Bush Telegraph

1 August, 2022, Ross Goldingay, “Good news: highway underpasses for wildlife actually work” in The Conversation

A koala on Heathcote Road, Xmas 2020. Photo credit: Jesse Campbell

22 March, 2022 “Experts to lead webinar discussion on need for wildlife crossings in Sutherland ShireThe Leader

25 September, 2021 “Koala to be released soon back into bushland near where he was found injured at Woronora” The Leader

13 September, 2021 “WIRES removes koala from Woronora bushland after public attention and injury concerns” The Leader

21 August, 2021 “Call for government urgency as koala deaths on Heathcote Road escalate” The Leader

7 Jul 2021, “Cars strike koalas on Sydney’s fringe with delays to wildlife underpasses” ABC Illawarra

31 May, 2021 “Sydney Water prepares to sell off bushland in area occupied by koalas at Woronora Heights” The Leader

1 May, 2021 “New documentary film tells story of koalas on Sydney’s southern and south-western fringe” The Leader

10 April, 2021 “Sydney’s hamlet tragedy: urban sprawl conquers all” The Sydney Morning Herald

22 February, 2021 “Submission to Transport NSW regarding the Heathcote Road Bridge Widening Project”

6 February, 2021 “‘How good were koalas?’: A national treasure in peril” The Sydney Morning Herald

10 January, 2021 “Drones count koalas faster and cheaper than manual spotting methods: study” ABC News

19 December, 2020 “Reuben may be heading to the shire for Christmas” The Leader

3 December, 2020 “St Joseph’s Primary School students support koala conservation” The Leader

27 October, 2020 “Destruction of Appin koala habitat a disgrace” The Sydney Morning Herald

1 October, 2020 “Koala carnage on Sutherland Shire roads continues” The Leader

30 September, 2020 “Video of mother and baby koalas on Heathcote Road to add pressure for protection measures” The Leader

21 September, 2020 “Fence-off the koala kill spots, environment groups say” The Leader

6 August, 2020, A koala found in Kirrawee – captured and released in the Royal National Park: “Rescue koala fitted with tracking device before being released in Royal National Park” 7NEWS Sydney

21 July, 2020, Sutherland Shire Environment Centre Submission to Sutherland and Wollongong Councils – Recommendations for Increased Protection for Koalas and Resilient Habitat in the Sutherland Shire, to Helensburgh

10 July, 2020, “Renewed calls to protect koalas who move through area from upper Georges River to shire’s western fringe” The Leader

May, 2020 Protecting Sydney’s Macarthur Koala Colony – The Survival Plan, Total Environment Centre

20 February, 2020 “Analysis: Koalas: new laws – old tricks”, Environmental Defenders Office

18 February, 2020 “Bushfires hastening NSW koala extinction” The Leader

20 January, 2020, Sutherland Shire Environment Centre Submission to Matt Kean MP, NSW Minister for Energy and Environment, regarding the expansion of Heathcote National Park and protection of Koala Habitat in the Sutherland Shire,

16 January, 2020 “Sylvania Veterinary Hospital helps nurse injured koala back to health” The Leader

Saving Wildlife – the Compton Road effect, Griffith University https://www.griffith.edu.au/research/impact/compton-road-wildlife-corridor

14 August, 2019 “Say goodbye to southwest Sydney koala population” Independent Australia

Wildlife Crossings supported by the NSW Roads and Maritime Services – “Gliders take the high road: Study proves highway fauna crossings are being used by threatened species”, ABC News, 19 July, 2018

Dean Karas, 2018 “Scoping for potential wildlife crossings for koalas and marsupial gliders in the Sutherland Shire and Campbelltown regions of New South Wales, Australia” University of Wollongong Thesis Collection

Wildlife Movement Solutions Brisbane City Council https://www.brisbane.qld.gov.au/clean-and-green/natural-environment-and-water/biodiversity-in-brisbane/wildlife-in-brisbane/wildlife-movement-solutions

3 October, 2018 “Six koalas killed on Heathcote Road in last year sparks call for action” The Leader

27 September, 2017 “Rare sighting of koala mother with her joey in Heathcote National Park” The Leader

7 November 2016 “Mt Kembla’s ‘new’ koala population” NSW Department of Planning and Environment media release

26 July, 2016 “Koalas tunnels and bridges prove effective on busy roads” Brisbane Times

In Search of the Illawarra Koala blog post, with a history of koala sightings around the Illawarra, dating back to 1803

11 September, 2013 “Injured koala rescued on Heathcote Road”, The Leader

Academic articles and reports on koala surveys and wildlife crossings

Ross L. Goldingay, David Rohweder, Brendan D. Taylor, Jonathan L. Parkyn, 2022, “Use of road underpasses by mammals and a monitor lizard in eastern Australia and consideration of the prey‐trap hypothesis“, Ecology and Evolution, 12, e9075

Koala and joey in Heathcote National Park. 5 November 2016. Photo credit: Jason Luke

Ryan R Witt, Chad T Beranek, Lachlan G Howell, Shelby A Ryan, John Clulow, Neil R Jordan, Bob Denholm, and Adam Roff, 2020, “Real-time drone derived thermal imagery outperforms traditional survey methods for an arboreal forest mammal“, Plos one, Volume15, Issue11

Ross L. Goldingay, Brendan, D. Taylor, and Jonathan L. Parkyn, 2019, “Movement of small mammals through a road-underpass is facilitated by a wildlife railing”, Australian Mammalogy, 41: 142–146

Ross L. Goldingay, Brendan, D. Taylor, Jonathan L. Parkyn, and John M. Lindsay, 2018, “Are wildlife escape ramps needed along Australian highways?”, Ecological Management & Restoration, Vol 19 No 3 September: 198-203

R. L. Goldingay, 2017, “Persistence of Australia’s most threatened snake (Hoplocephalus bungaroides) in Australia’s oldest National Park”, Journal of Zoology 304: 202–209

Stuart Pell and Darryl Jones, 2015, “Are wildlife overpasses of conservation value for birds? A study in Australian sub-tropical forest, with wider implications”, Biological Conservation 184: 300–309

John Lewin, [Koala and young], watercolour on paper, 1803, Mitchell Library ML896, Sydney, as per Michael Organ, 2006

Brendan D. Taylor and Ross L. Goldingay, 2013, “Squirrel gliders use roadside glide poles to cross a road gap”, Australian Mammalogy, 35: 119–122

Brendan D. Taylor and Ross L. Goldingay, 2012, “Restoring Connectivity in Landscapes Fragmented by Major Roads: A Case Study Using Wooden Poles as Stepping Stones for Gliding Mammals”, Restoration Ecology, November, Vol. 20, No. 6: 671–678

August 2013, Tristan Lee, “Fine-scale population genetics studies of koala populations in New South Wales and Victoria” University of Sydney

3 September 2012, Ross Goldingay, “What Role Does Ecological Research Play in Managing Biodiversity in Protected Areas? Australia’s Oldest National Park as a Case Study” in Proceedings of the Linnean Society of New South Wales 134: B119-B134

VicRoads Fauna Sensitive Road Design Guidelines, 2012

2006, Michael Organ, The Scientific Discovery of the Koala: Hat Hill (Mount Kembla), New South Wales 1803

4 December 2003, “Cutting the carnage: wildlife usage of road culverts in north-eastern New South Wales”, CSIRO Wildlife Research 30(5)

Spot the koala, Royal National Park, January 2020 – photo credit – Audley Boatshed

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