Making it possible to hear them growl here again!
This is Stage 2 of our Growler Rewilding Project – translocating, quarantining, breeding and researching the establishment of a captive population as a major source for release of Growling Grass Frogs at Winton Wetlands (and eventually, wider areas in NE Victoria). We thank both the Ross Trust and Wettenhall Environment Trust for the funding for stage 2 of our project.

Project Summary

Growling Grass Frogs (GGF) were once common in wetland ecosystems but are now regarded as an endangered species in Victoria (FFG Act) and elsewhere in their natural range. They were once present at Winton Wetlands and have not been recorded in recent years and are now locally extinct. However, they are important species in an ecosystem as they are predators of other frogs and insects which is functionally different from other frog species. They are also large and known to be a crucial food source for predatory wetland birds, which the wetlands are also trying to support. Ultimately, rewilding of the species will help secure this species status locally and regionally, increase biodiversity on site and will restore critical ecological functions and processes to Winton Wetlands.

If a healthy population of GGF can be established on the reserve, the benefits will be three-fold- 1) it will aid in restoring ecological function and biodiversity to the wetlands themselves, 2) demonstrate the proof of concept of the method used to rewild the species in a wetland; and 3) it will create a valuable local ‘source’ population for further rewilding events in other wetlands within the region.

Our initial project, funded by Wettenhall Environment Trust, gives us confidence that we can rewild Growling Grass Frogs based on habitat suitability and disease risk, and we have set up a system of monitoring using audio recorders and software. We have also completed translocation risk assessments and designed infrastructure to allow the breeding and re-introduction of the species.

The second stage of our project will see the establishment of our:

• Translocation Protocols, Approvals and Quarantine Facilities
• Breeding and Feeding System; and
• Research and Monitoring Plan and Equipment

This summary is to explain the “Growler Rewilding Project Stage 2” which is the next essential step to establish a captive breeding population to allow re-introduction of the species on-site and could be used as a source population for regional rewilding projects.

The project is harnessing the latest science and practice of the groups working with GGF across Australia (we are in communication with experts in Adelaide, NSW and Queensland and have Dr Geoff Heard, Australia’s pre-imminent GGF researcher, and, Dr Karen Rowe – Museum Victoria, on our team), building on our experience on site as well as our network of community groups, volunteers and local schools to all assist in the project.

We will involve the community (through volunteers and schools) in each step along the way as we bring these animals into our care. Volunteers in the community can help feed and look after the animals, see the animals in care (there will be an observation window in our Science Centre) and learn about the work we are doing – through tours of the general public and school groups as well as ultimately we will invite the community to be involved in tadpole/metamorph release days.

Translocation Protocols, Approvals and Quarantine Facilities are required to source, house and breed GGFs. We will bring the broodstock onsite, ensure they are disease free by keeping them in quarantine and treating any suspected infections. We have appropriate facilities being developed for our turtle project but further funds are required to extend these and make a section suitable for frog husbandry. We will also establish a communications and engagement plan to involve as many volunteers into the project as we can.

The Breeding and Feeding System will allow us to breed large numbers of GGF ultimately to release on site but these animals will require vegetable food as tadpoles and insect prey for adults to ensure they are in excellent condition before release and to encourage successful breeding.

A Research and Monitoring Plan and Equipment will allow the team to establish the required monitoring and research plan to assess population genetics and the success and movement/dispersal of the GGF through the wetlands. Research will be undertaken through our partners at the Museum and various universities as the program develops. We already have a great record of the frogs onsite using audio recorders. We analyse these recordings with sophisticated software which allows us to use artificial intelligence to identify frog species across the site, throughout the diurnal and seasonal cycles.

The third stage of the project, will see further breeding, multiple releases onsite (ultimately growling grass frogs will be available to other community groups and agencies to rewild on their locations), further monitoring and research to ensure the process is successful and repeatable (becoming a model for others).

Picture:  Growling Grass Frog Call as revealed by Kaleidoscope software.