Reintroduction of the Green and Golden Bell Frog Litoria aurea to Pambula on the south coast of New South Wales

Translocation is occasionally suggested as a last resort strategy for dealing with 'unavoidable' loss of Growling Grass Frog Litoria raniformis habitat in urbanising landscapes. However, examples of attempts to translocate an entire population of L.. raniformis are rare and their success (or lack of success) is poorly documented in the literature. In this study, we detail the translocation of a population of L.. raniformis from a farm dam being destroyed for residential development to a purpose-built wetland 480 m away. The population was translocated between November 2010 and May 2011. We used mark-recapture to estimate the number of frogs in the population prior to translocation. Visual counts of L.. raniformis at the dam indicated a maximum of 39 adult frogs to be present while 355 frogs were marked over the course of a single season (November 2010 to March 2011). Translocation of 156 frogs and unassisted colonisation by 32 frogs resulted in an estimated 70% of adults marked at the dam moving to the wetland and 91% of those remained there for the duration of the translocation study period. The population and two measures of habitat quality (aquatic vegetation cover and water quality) were monitored for three active seasons post-translocation. Successful breeding was demonstrated for the first year only. A decline in breeding success was attributed to a reduction in habitat quality at the wetland, particularly the loss of submergent and floating vegetation due to the presence of Common Yabby Cherax destructor, a species that did not occur originally in the dam. We believe that colonisation of the wetland by this crustacean was due to the wetland being constructed on-line. An attempt to control the C. destructor population and re-establish the aquatic vegetation was unsuccessful. We encourage the publication of all successes and failures in future attempts to establish translocated bell frog populations. If further experimental translocations have low success rates, then translocations should be reconsidered as a conservation strategy for L.. raniformis in urbanising landscapes and greater emphasis placed on in situ habitat protection.

Section: How Does This Experience Compare With Other Bell Frogs Transsupporting

confidence: 52%

Translocation of the threatened Growling Grass FrogLitoria raniformis: a case study

Koehler¹,

Gilmore²,

Newell³

2015

“…As a colonizing and generalist species, L. aurea should be an ideal candidate for producing successful conservation programs. However, despite the use of habitat templates based on perceived microhabitat selection paradigms, nearly all habitat creation and reintroduction plans have been unsuccessful in producing a self-sustaining breeding population (Daly et al 2008;Pyke et al 2008;Stockwell et al 2008;White and Pyke 2008a). To date, the most successful habitat creation program to result in a selfsustaining population has been at Sydney Olympic Park.…”

Section: Microhabitat Selection Varies By Sex and Age Class In The Enmentioning

confidence: 99%

Microhabitat selection varies by sex and age class in the endangered green and golden bell frog Litoria aurea

Valdez¹,

Klop‐Toker²,

Stockwell³

et al. 2016

Although amphibians are one of the most threatened animal groups, little published evidence exists on effective management programs. In order for conservation initiatives to be successful, an understanding of habitat use patterns is required to identify important environmental features. However, habitat use may differ between the different sexes and age classes due to different behavioural and resource requirements. For this study, we compared microhabitat use during the active breeding season among the sexes and age classes in the endangered green and golden bell frog Litoria aurea, a species which has had several failed management programs. We found aquatic vegetation was selected for by every L. aurea class, and should be the focus of future management plans for this species. Females were the only class to select for terrestrial vegetation more than availability. Increasing the amount of terrestrial vegetation around ponds may help encourage female occupancy, and possibly improve management outcomes, as they are typically a limiting resource. Although large rock piles have been used in past L. aurea habitat management, they were selected for by adults and juveniles, but not metamorphs. Therefore, large rocks may not be necessary for captive breeding portions of management initiatives, which typically only involve tadpoles and metamorphs prior to release. The results indicate that the most appropriate management plans should contain a habitat mosaic of various microhabitats, such as a large proportion of aquatic and terrestrial vegetation with patches of bare ground and a small proportion of rocks for basking and shelter. Recognizing differences in microhabitat use patterns between individuals in a population and implementing them into management strategies should be a pivotal step in any conservation plan.

“…The cause of this decline has not been determined although habitat modification, predation by the introduced fish Gambusia holbrooki and the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis have been implicated (Pyke and White 2001;Pyke et al 2002;DEC NSW 2005). As such, the introduction of the bell frog into rehabilitated or supplementary habitat has been widely used in its conservation with programs currently occurring in Botany, Marrickville, Collaroy, Arncliffe and Pambula (DEC NSW 2005;Daly et al 2008;Pyke et al 2008) .…”

Section: Introductionmentioning

confidence: 99%

The impact of the Amphibian Chytrid FungusBatrachochytrium dendrobatidison a Green and Golden Bell FrogLitoria aureareintroduction program at the Hunter Wetlands Centre Australia in the Hunter Region of NSW

Stockwell¹,

Clulow²,

Clulow³

et al. 2008

Reintroduction programs are used widely in conservation to reduce a species' risk of extinction and amphibians are considered suitable candidates for such programs because of their behavioural simplicity and high reproductive output. The Green and Golden Bell Frog Litoria aurea is an endangered species that has been reintroduced into several areas within its natural range, but the outcome of these programs remain unknown. This paper presents the results from the first release of the bell frog in the Hunter Region of New South Wales. This reintroduction released 850 tadpoles into a closed system of three ponds and rehabilitated habitat. Tadpole survival was high but following metamorphosis a decline in numbers began that continued for 13 months and resulted in the disappearance of all released bell frogs. The cause of this decline was investigated and eventually attributed to infection by the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis. These results emphasize the importance of including regular chytrid testing in the monitoring of both natural populations and reintroduction programs, particularly as few sick and dead animals were found to indicate its presence.