re-introducing

Stuttering Frog

Stuttering Frog Mixophyes balbus

Shoalhaven Landcare and Bundanon Trust have partnered to reintroduce the locally extinct Stuttering Frog into the Shoalhaven. This page will provide updates on the project. The project was launched at Riversdale on 1 December 2017. The project is supported by an Environmental Trust grant.

Project Outline

The proposal will benefit the species by expanding the species existing distribution into a portion of its former range and hence increase the geographic security of the species. G Daly, Translocation Proposal

Previously widespread throughout eastern NSW, the species is no longer found south of Sydney. The Stuttering Frog was wiped out in southeastern NSW by the highly infectious Chytrid Fungus, an introduced disease which has decimated populations of Australian amphibians over the past 30-40 years. To establish disease-free populations, chytrid-free individuals will be released at two sites in the Shoalhaven – Bundanon Trust’s Riversdale property and a private property along the Cambewarra Range. The project is led by Garry Daly, Director of Gaia Research P/L and a member of the Declining Frogs Working Group.

The project intends to re-establish the southern species at three sites in the Shoalhaven Local Government Area in the suburb of Tapitallee, namely the headwaters of Tapitallee Creek, Bengalee Ck and the unnamed creek at Riversdale. This action will work towards increasing the number of populations/individuals of this species, re-establish the pre-European biodiversity of the receiving area and help restore ecosystem function. The aim is to provide a planned, comprehensive program for the translocation of captive bred tadpoles and disease free metamorphlings into a portion of the species historic range to assist the recovery of the species and ecosystems in the area.

The benefits of the project are many. For the species it will re-establish a genetically robust population within the former range of the frog. For amphibian conservation it will provide data on a strategy that can be used for further re-introductions of stream breeding species

The Stuttering Frog Mixophyes balbus is listed as Vulnerable under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and Endangered under the NSW Threatened Species Conservation Act 1995. Historically the species occupied eastern-flowing streams along the Great Dividing Range, between the Cann River catchment in East Gippsland Victoria, north to the Clarence River catchment in north-eastern New South Wales. What we once considered to be the Stuttering Frog now seems to be two species. The southern species historically occurred south of the Barrington Range to Myall Range south to northern Victoria. This species has severely declined in distribution and abundance over the last thirty years. Populations south of Ruby Creek in the Blue Mountains National Park (NP) are considered extinct (G. Daly unpub. data) and it is likely that the frog no longer persists at this location. South of Sydney, the last known population was at Macquarie Pass NP, which persisted until 2006 (Daly and Craven 2010).

env trust
SLC
tadpole

Mixophyes balbus tadpole

Project Update 5 Releasing the first frogs 23-06-19

Pathology results showed none of the small frogs in captivity had the frog pathogen chytrid, which allowed for the release of six frogs at Riversdale.

Over the last 12 months the Stuttering frog project has progressed significantly. Pathology results showed none of the small frogs in captivity had the frog pathogen chytrid, which allowed for the release of six frogs at Riversdale. The frogs were successfully bred in captivity and tadpoles are now being raised so we can expect to release more in future. More tanks were set up at the Coffs Harbour Frogarium to house the growing captive population.

Additional vegetation beside the creeks has also been successfully rehabilitated with hundreds more trees and shrubs planted. Some of these were replanting from losses incurred after Wombats knocked over the tree guards and ate the seedlings. However, most of the plantings from 2018 are doing very well despite the wombats and drought. In total, 53 species have been planted to increase the biodiversity of the site.


Project Update 4 Planting Day 17-06-18

Over 30 volunteers and project staff worked in cold windy conditions around the creek at Riversdale on Sunday June 17 to build tree guards and plant rainforest species. Over 350 trees were planted to improve the habitat for the frog at Riversdale in preparation for a proposed release in late spring. In the same week we received some sustained rainfall. A full list of species planted can be found below.

Planting day


Singing the return of the Stuttering Frog

Local school children from Nowra East Public School perform songs learnt in their Song Company Workshop for our Shoalhaven Landcare volunteers and learn about the Stuuttering Frog project, at the Creek at Riversdale.


Project Update 3 15-05-18

I collected around 700 tadpoles and took them up to Coffs Harbour
- Garry Daly

Garry Daly revisited the mid-north coast to progress the Stuttering Frog project. He looked at the Copeland and Bowman sites to assess the vegetation associations at those sites and the number of tadpoles in the creeks - as a measure of recruitment and breeding at the sites. There was only one tadpole found in Copeland Creek, that had somehow survived when the creek had dried up. In contrast the sites in Bowman SF had thousands of tadpoles. These findings relate to what Garry observed in February, that is no Stuttering Frogs calling or active at Copeland even though there had been decent rain and the creek was flowing well. When we surveyed the Bowman sites the following night there were lots of frogs calling and Garry was able to catch a female that now forms part of our captive breeding colony.

In Mid May Garry collected around 700 tadpoles and took them up to Coffs Harbour where the frog whisperer has his frogarium. Below is an image of tanks that he has set up. One has adults and the other has tadpoles. There are other tanks with tadpoles and frogs. Garry bought more plants for the re-vegetation along the creek at Riversdale, cut more wire for tree guards and cut down some dead wattles in preparation for another round of planting that will occur from May 21. We will invite the students from Nowra East Public School who are onsite participating in a Song Company Choral Workshop to plant and stake.

Tadpole stage...

Project Update 2 15-05-18

The main objective is to re-establish a self-sustaining chytrid Batrachochytrium dendrobatidis (Bd) resilient wild population of M. balbus on the project sites. Initially, wild adults from further north will be bred and released. Then tadpoles will be released annually for five years to form the trans-located population. Capture tadpoles from these sites, will be raised in captivity until they metamorphose and if they test positive for Bd then treat them chemically to eliminate the pathogen prior to release. Releases of tadpoles will occur for five consecutive years.

Our breeding colony of Mixophyes balbus is happening. Garry Daly reports that we caught a few gravid females a week ago and at least one has spawned. Stuttering Frogs lay between 130 and 830 eggs so on average we expect to have about 450 tadpoles in a few weeks. This is great news as we have achieved one of the major objectives of the project. This would not have been possible without the help of NSW Forestry Corporation staff. With their permission I have changed the Translocation Proposal and other licences to include another State Forest where we can collect animals. Forestry Corporation staff also gave logical support in collecting the females.



Project Update 1

The main objective is to re-establish a self-sustaining chytrid Batrachochytrium dendrobatidis (Bd) resilient wild population of M. balbus on the project sites. Initially, wild adults from further north will be bred and released. Then tadpoles will be released annually for five years to form the trans-located population. Capture tadpoles from these sites, will be raised in captivity until they metamorphose and if they test positive for Bd then treat them chemically to eliminate the pathogen prior to release. Releases of tadpoles will occur for five consecutive years.

Mixophyes balbus

The Stuttering Frog is relatively large and muscular, growing to about 8 cm in length. It has large, black eyes and vertical pupils, webbed feet, barred hind legs and a black line from the snout, through the eye and above the ‘ear’. The body colour is brown to olive-green and may be broken into irregular blotches. The underside is creamy-white. The adult has a pale-blue crescent across the upper half of the eye; this, and the call - a stuttering ‘ugh’ or ‘op', distinguishes the species from other barred frogs. The tadpole is dark brown to black and grows to 6.5 cm in length. The other common name for the Stuttering Frog is the Southern Barred Frog.

Habitat and ecology

  • Found in rainforest and wet, tall open forest in the foothills and escarpment on the eastern side of the Great Dividing Range
  • Outside the breeding season adults live in deep leaf litter and thick understorey vegetation on the forest floor.
  • Feed on insects and smaller frogs.
  • Breed in streams during summer after heavy rain.
  • Eggs are laid on rock shelves or shallow riffles in small, flowing streams.
  • As the tadpoles grow they move to deep permanent pools and take approximately 12 months to metamorphose.

Threats

  • Modification and loss of habitat.
  • Disease - chytrid fungus
  • Changes to natural water flows and water quality
  • Predation of eggs and tadpoles by introduced fish
  • Damage to habitat and impacts on water quality from forestry activities
  • Damage (vegetation removal, disturbance, turbidity) to habitat by domestic stock, feral cattle and pigs
  • Poor knowledge of the species' distribution, taxonomy and history of local extinction

Information adapted from Department of Environment and Energy, Australian Government website

Distribution

Distribution map for Stuttering Frog