Search
  • lynetteplenderleith

Dr. David Hunter, "The Good, The Bad and The Ugly of Frog Conservation" June 2019

June’s presenter is Dr. David Hunter. David has been involved in frog research and conservation over the past 25 years. While undertaking his science degree at Latrobe University in Melbourne, he volunteered and worked as an assistant on the Spotted Tree Frog and Baw Baw Frog recovery programs. He then moved to Canberra, where he undertook his Masters and PhD research into the conservation management of Corroboree Frogs and the Booroolong Frog. David has since been working as a Threatened Species Officer for the NSW Government, and currently oversees the management of six threatened frog species in southern NSW.


Dave will talk about how human perceptions of the value and aesthetics of threatened frogs have influenced conservation efforts for these species.


The June 2019 Frogs Victoria event saw some 40 people crowded around the projector at the Elgin Inn to watch the committee struggle with technology. Having given the long-suffering tech support the night off, for the first twenty minutes the livestream worked and the slides worked, but not both at the same time!


But as entertaining as it was, the audience had actually come to see what promised to be an excellent talk by well-known and accomplished herpetologist Dr. David Hunter. And we were not disappointed. Dave has spent a good 25 years herping about South-Eastern Australia and is currently employed by the New South Wales government as a Threatened Species Officer. He travelled from his office in Albury to entertain and inform us about “The Good, The Bad and The Ugly of Frog Conservation”. Conservation, as Dave told us (as he was told himself by a mentor) is 10 % about the threatened species and 90 % about people. The species featured in his presentation all have outcomes greatly determined by people. As Dave told us, “Achieving good outcomes for threatened species is all about people and people’s values and perceptions”.


Dave showed us a picture of Frogs Vic Vice President Nick Clemann, with the question: “Good, bad or ugly?” Just when we all thought it had gone horribly wrong, we realised that Dave was right, perception is everything! We also realised that there is something quite special between Dave and Nick…


Dave also used the feral horses of the Alpine region as an example. Horses live throughout Australia and throughout the world, but because of the value placed on them, they continue to threaten the exclusive biodiversity of the high country. The sentimentality for horses is being put before the vital and threatened habitat of animals and plants that live in the Australian Alps.


Dave says that the Southern Corrobboree Frogs would likely be extinct in the wild without Gerry Marantelli and the ARC (Amphibian Research Centre), Zoos Victoria and Taronga Zoo. The species only just persists in the wild and is really only robust in captivity. This seems to be mostly because of Chytridiomycosis, which is responsible for many amphibian deaths worldwide. Chytrid is particularly problematic amongst amphibian diseases because it can be carried by most frogs, but only a few species become ill and die. This makes reservoir hosts a big issue. Southern Corrobboree Frogs share habitat with the Common Eastern Froglet, of which, most, if not all, individuals in the high country are infected with chytrid. Research from Ben Scheele’s PhD showed that the Corrobboree Frogs were only doing well where habitat is not suitable for Common Eastern Froglets. Dave says that current thinking is about how we can keep the two species separate to protect the Southern Corrobboree Frog.


To this end, several techniques are being tested. They include keeping Southern Corrobboree Frogs in containers and enclosures that Common Eastern Froglets can’t access. Dave says that there has been some success, but that further development is required. The good news is though, that the Southern Corrobboree Frogs are staying alive and staying chytrid free. Other trials include artificial wetlands where the Common Eastern Froglets don’t occur. These studies have involved lots of people including Phil Byrne (University of Wollongong) and Ben Scheele (Australian National University) as well as teams from Zoos Victoria, the ARC and Gerry Marantellli. Dave was keen to emphasise that the teamwork required to carry out such research is vital. Again, “the human dimension is everything”.


The work to save the Corrobboree Frogs has not been all that easy, froggy-difficulties notwithstanding. Dave says that it was difficult to secure funding for the projects for years. The negative effects of Hugh Possingham and friend’s proposed “conservation triage” that many of us will likely feel for years to come had hit the Corrobboree Frog conservation projects hard. If you are not familiar with the conservation triage idea, it is basically a suggestion that species such as the Orange Bellied Parrot, the Christmas Island Blue-tailed Skink and the Southern Corrobboree Frog should be allowed to go extinct in order to reallocate resources to other species. However, there were some critical details missing from the blithe and careless proposal. Dave argued that conservation triage is a false premise that did a lot of damage to the value, resources and effort placed on threatened species. An assessment with which this author wholeheartedly agrees.


Zoos Victoria came to Dave’s rescue with their “Fighting Extinction” campaign. Zoos Victoria and Dave refused to turn their backs on such special animals as the Southern Corrobboree Frog. As Dave says, the letting go of one species, erodes the value placed on all threatened species. Dave would like to see some more work done on whether the money saved by not having done so would have been more effective elsewhere. Wouldn’t we all.


After pretending that he is little responsible for the great work done on Southern Corrobboree Frog conservation, Dave then claimed that he hasn’t had much to do with the great impacts on Spotted Tree Frog conservation. The Spotted Tree Frog is now found predominantly in Victoria where Matt West is studying the species. Dave humbly suggested he was a sideshow when it comes to the Spotted Tree Frog, but he was on the front line when we saw the New South Wales population of the species disappear. Dave and his team managed to save one individual which was married (Dave’s word, not mine but I kept it because there’s something romantic about it) up with some individuals from the closest Victorian site. They successfully bred under Gerry Marantelli’s careful watch. Some of them were released in a few places where Spotted Tree Frogs were known historically and they did fairly well and even bred. Sadly, the cold, wet, La Niña years of 2010-2012 brought some higher rates in chytrid fungus and a fast decline in their number. A rethink resulted in some assisted colonisation. Dave then attempted a spoiler for Geoff’s talk next month – he told us about habitat refuges where chytrid doesn’t have the upper hand over the frogs. Warmer microclimate spots might keep chytrid at bay. Dave found a site with no other frog species and dataloggers were put in basking sites (Spotties love to lie in the sun!) to monitor temperatures. And there is good news – the frogs are breeding and the next generation wild-bred individuals are also breeding. It bodes well for the future with other sites lined up as potential release locations that have similar thermal patterns. Dave is cautiously optimistic though – chytrid will get there eventually and may wipe out the population at that point. The frogs might also be victims of their own success – they have spread downstream as far as an area with Booroolong frogs that have chytrid.


The Booroolong Frog, is not immune to the challenges of chytrid – it has suffered massive range reductions. Booroolong Frogs are, like many other species, threatened by multiple factors such as invasive fish and habitat degradation. But of these, habitat degradation is actually possible to manipulate. The Booroolong Frog breeds in water-filled rock crevices. Fussy, I thought. Until Dave told us that actually, that’s ALL they need. The waterways that house the water-filled rock crevices in which the frogs breed are often grazed and trampled by stock which changes the habitat dramatically and reduces the number of shallow water-filled rock crevices for the Booroolongs. Invasive willow trees also cause problems but these are easily managed and Booroolong Frogs do an excellent job of recolonising streams once the problems are removed. Dave says that Booroolong work is very rewarding and working with the farmers to exact positive change is something he really enjoys.


Dave stifled a bow and acknowledged the room full of Sloane’s royalty. Sloane’s froglet was named after Ian Sloane (Frogs Vic Secretary Teisha’s grandfather), by Frogs Vic Patron Murray Littlejohn, who described it. Dave talked about the first Australian Sloane, William, who learnt the local language and worked with the first peoples of his local area to protect their land, culture and artefacts as well as protecting the natural heritage of the land that he farmed.


There seemed to be little known about Sloane’s Froglet in NSW so Dave went to look for them. Historically the species was thought to have gone all the way up to the Queensland border, but on further investigation, Dave thinks that they were largely misidentified, as were a lot of the southern records! When Dave surveyed for them, he actually only found the species in a few areas, including around Albury and along the Murray. The habitat in which Sloane’s Froglet lives is disappearing really fast. The wetlands on which Sloane’s Froglet rely are being drained or developed in much the same way as the Growling Grass Frog habitat is around Victoria. Dave is working hard with the landowners and managers to encourage empathy towards the frogs, which thankfully seem a little more open to artificial wetlands than the likes of the Growling Grass Frogs. The right vegetation structure and the right water depth seems to be all it takes to keep them happy, which is great news and the urban councils and developers are willing and able to accommodate them. The programme is therefore mostly about community engagement, including the Sloane’s Froglet citizen science “Sloane’s Champions” project. Dave started the project amid nightmare data collection that has since been made infinitely better by the FrogID app.


And so concluded Dr. Dave Hunter’s presentation. A whirlwind trip around the very different and very important habitats of three threatened frog species. Whether any of them were good, bad or ugly lies in the perception and values of the audience, but thanks to some of Dave’s work, they are all still here.


For the frogs,

Lynette Plenderleith

Chair, Frogs Victoria.

22 views