The how and why
Why are growling grass frogs (growlers) being returned to Winton Wetlands, one of their traditional homes but a place where they’d become locally extinct?
Growling Grass Frogs were once common in wetland ecosystems but are now regarded as a vulnerable species in Victoria, Australia, and elsewhere in their natural range. They were once present at Winton Wetlands but have not been recorded for many years and are now considered locally extinct.
However, they are an important species in the wetland ecosystem as they are predators of other frogs and insects, functionally different from other frog species. They are also large and known to be a crucial food source for predatory wetland birds, which the Winton Wetlands Committee of Management wants to support and encourage.
Why bother? Why does it matter?
If a healthy population of ‘growlers’ can be re-established on the reserve, the benefits will be three-fold. It will:
1) help restore ecological function and biodiversity to the wetlands
2) help prove the method being used to rewild the species in a wetland
3) create a valuable local ‘source’ population for further rewilding events in other wetlands within the region.
In short, rewilding of this species will help secure the species’ status locally and regionally, increase biodiversity on-site and will restore critical ecological functions and processes to Winton Wetlands. This in turn will make a contribution to the health of the broader natural environment in which human communities live.
What’s special about ‘growlers’?
Growling Grass Frogs occupy a distinctive place in the wetland eco-system, one not occupied by other frog species. They help to maintain population balance, being both predator and prey for other species. They are particularly attractive as prey to some larger birds and reptiles.
They might well be described as an iconic or flagship species, particularly for wetland restoration as their needs (for habitat, food and water quality) reflect the needs of many other wetland species. They are also a very charismatic species, being large and often bright green, with a distinct deep growling call. Due to their size, they are more often observable than other frogs to members of the public.
How long has this been in the making?
Consideration of the re-introduction of growlers goes back to 2012, not long after the establishment of Winton Wetlands as a wetland restoration project, when preliminary work got under way to assess causes of the decline of the species across its traditional territory.
Each year a Science Forum is held on-site at Winton Wetlands. A workshop held as part of the 2016 Science Forum identified that a return of the Growling Grass Frog to Winton Wetlands would be feasible and worthwhile as part of the overall wetland restoration program. Since then, surveys and audio recordings of frogs have confirmed the absence of the species and data has been collected to assess the habitat suitability.
Leading expert Dr Geoff Heard confirmed the Mokoan Ponds area of the reserve as suitable habitat for the species in 2021. Since then, the planning team has worked through an extensive approvals and permits process, including comprehensive risk assessments and ethical checks, leading to the creation of a custom built quarantine Laboratory and captive breeding habitat pods
Winton Wetlands Committee of Management has been collaborating and sharing knowledge with other groups working on the species including Dr Geoff Heard, Dr Matt West (University of Melbourne/Wild Research Pty Ltd), Museums Victoria, the Nature Glenelg Trust in South Australia, Melbourne Water, Taronga Zoo and the Victorian Department of Energy, Environment and Climate Action.
Winton Wetlands has established a Practitioners’ Network of about 50 scientists, managers and community experts to help advise, and share information about Growling Grass Frogs.
Goulburn Broken Catchment Management Authority, North Central Catchment Management Authority and West Gippsland Catchment Management Authority all have ambitions to expand growler habitat with possible translocations and these agencies have maintained contact with one another.
Winton Wetlands’ overall ecological renewal program is guided by an Environmental Strategic Advisory Panel and key strategic planning documents. Panel members are:
- Professor Max Finlayson (Charles Sturt University)
- Professor Peter Gell (Federation University)
- Dr. Michelle Casanova (Federation University)
- Dr. Catherine Allan (Charles Sturt University)
- Susan Campbell (Community Member)
- Geoff Barrow (Friends of Winton Wetlands and Community Member)
- Suz Christison (Winton Wetlands Committee of Management)
- Dr. Dennis O’Brien (Chair, Winton Wetlands Committee of Management)
- A representative from the Department of Energy, Environment and Climate Action
So, do you just put frogs in a bucket and drive them where you want them to go?
Not quite. The process of investigation, planning and preparation has been extensive, with careful scrutiny and approvals required at both State and Federal levels.
These approvals take into account the skills and expertise of the people involved, the precautionary measures in place to deal with potential incidents such as the outbreak of disease, and other health, safety and animal welfare considerations.
The final approval requirement, under the Environment Protection and Biodiversity Conservation Act (1999), was provided by the Federal Environment Minister, Tanya Plibersek, in February 2023, on her department’s recommendation.
The translocation from Bendigo to Winton involved many steps along the way.
At Bendigo, frogs were captured by hand and assessed for general health. Swabs were done to check for chytrid fungus and genetic samples were taken, using ethically approved protocols. For transport, animals were housed in individual sealed and disinfected containers. Transport containers were stored in climate-controlled eskies placed into climate-controlled cars. To minimise the time between capture at Bendigo and release at Winton, animals were transported overnight. Health checks of all transported animals were conducted every hour during transport and then again on arrival at the Winton facility. This translocation involved a team of 12 people including Winton Wetlands staff, researchers and volunteers (six at each end).
Are there risks? What kind of precautions are needed?
The project has involved three stages, recognising risks and the need to proceed with care.
The first stage assessed habitat suitability and disease risks, and included the set-up of a system of monitoring using audio recorders and software. The risks in translocation were systematically examined, leading to a risk assessment report and facilities designed to maximise the chances of successful breeding and ultimate re-introduction of the species.
The second stage saw the establishment of translocation protocols, approvals and quarantine facilities; a breeding and feeding system; development of a research plan, and monitoring equipment being put in place.
With the arrival of the first growlers, a third stage is commencing (see below).
Is there any community involvement?
Very much so. A key part of the third stage of the project is the launch of Taskforce Growler, a citizen science and engagement project.
It seeks to achieve community interest and involvement in the return of growlers to the region, through activities which include helping to provide food for growlers by supplying edible insects and other bugs, as well as the establishment of a network of practitioners able to share their knowledge about all aspects of growler conservation.
Taskforce Growler will support the success of this project long term across northern Victoria.
Who’s paying for this to happen?
The initial preparatory stages were funded by Wettenhall Environment Trust and the Ross Trust (philanthropic trusts), along with the Goulburn Broken Catchment Management Authority, the Murray Darling Basin Authority and the Victorian Department of Energy, Environment and Climate Action. There has been in-kind support from a number of sources, including Coliban Water and, very importantly, the Yorta Yorta community and local volunteers. Funding for subsequent stages is being sought through philanthropic sources and (it is hoped) from Federal Government grants. Further community fund-raising is also under way.
How can I contribute financially?
If you wish to help fund this important work, donations can be made via the links provided on the Winton Wetlands website – https://wintonwetlands.org.au/product/donation/ Donations are tax deductible.
Will we see more of this kind of thing in future?
The arrival of Growling Grass Frogs back at Winton Wetlands is an important step toward broader ‘rewilding’ activities across north-east Victoria and beyond, subject to sources of funding and levels of community support. It will help provide the “proof of concept” which can enable expansion into further rewilding activities over time, with more organisations and more communities becoming involved.
Other activities are also under way in support of the broad concept of ‘rewilding’. For example, two species of native fish have recently been returned to the wetlands after an absence of some years.
How can I find out more?
There is more information available here on the Winton Wetlands website – www.wintonwetlands.org.au – and this information is being updated regularly as new developments occur. Inquiries can also be directed to email@example.com, or by phone on (613) 5766 4462. Occasional updates are also being provided on Facebook, Instagram and Linked In.
10 March 2023