https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33311 Litoria aurea were placed in water collected from ponds that were used by this species for breeding and ponds where breeding was not detected at Sydney Olympic Park, Australia. After 19 days, the tadpoles were placed in enclosures in the same breeding and non‐breeding ponds, and monitored until they metamorphosed. There was no difference in tadpole survival, time to metamorphosis or body condition between the two treatments, indicating that poor water quality was not a cause of low pond occupancy by tadpoles at the site and resources should be directed towards investigating other potential causes. We suggest that this method of an ex situ followed by an in situ exposure study is an effective approach to eliminating or confirming poor water quality as a cause of population declines and reduced occupancy, for species that are aquatic for at least part of their life cycle. Other applications include establishing that artificially created habitat provides suitable water chemistry, or identifying a potential location for a reintroduction project.]]> Wed 10 Oct 2018 12:10:24 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23928 Litoria aurea, which exhibits high temporal variability in population size due to its fast life-history traits. Projections of population size from the viability model were highly variable, and removing parametric uncertainty only slightly improved overall model certainty, thus demonstrating the limits of population viability analysis for predicting abundance in fast life-history species. Sensitivity analysis identified recruitment of adults, female survival, male survival and rate of maturity as having the most impact on population viability. This population viability model provides a starting point to incorporate future research findings and better elucidate the causes of local extinction in this species. This study also reinforces the importance of egg-juvenile survival for amphibian populations, but also exemplifies the variability of amphibian viability analyses for identifying important parameters. As a case study for amphibian conservation, this analysis shows the utility of population viability analyses for fast life-history species, even with incomplete knowledge of all life-history stages.]]> Tue 31 Jul 2018 16:35:16 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:7586 Sat 24 Mar 2018 08:37:21 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:7612 Sat 24 Mar 2018 08:34:42 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20049 Sat 24 Mar 2018 08:00:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:19190 Sat 24 Mar 2018 07:55:02 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:5424 Sat 24 Mar 2018 07:48:15 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29935 Gambusia holbrooki, have been implicated in the decline of amphibians, which suffer high extinction rates globally. Although G. holbrooki is one of the most studied freshwater fish, its diet shows wide geographic variation and its impact on amphibian populations remains unclear. Stable isotopes ¹³C and ¹⁵N were used in 10 urban ponds in Sydney, Australia to compare the diet of G. holbrooki in January, April and May 2013 using a stable isotope mixing model. Gambusia holbrooki was carnivorous and fed on invertebrates (24–39%), tadpoles (25–32%) and conspecifics (20–45%). In contrast to previous studies, primary producers were a negligible part of Gambusia holbrooki diet (<10%). Its diet in late autumn comprised a high proportion of conspecifics (up to 45%) owing to the depletion of other food sources before winter (metamorphosis of larvae). This study provides evidence of high rates of predation on native tadpoles and invertebrates by a highly invasive fish. This knowledge should be incorporated into amphibian releases through head-starting tadpoles or using soft releases where tadpoles are placed in predator-free enclosures until larvae are large enough to avoid predation. Considering the dire conservation status of amphibians globally and the growing interest for invertebrates, it is suggested that stable isotopes are valuable to identify threats from predation in order to target conservation practice toward suitable priorities.]]> Sat 24 Mar 2018 07:31:02 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:48628 Fri 24 Mar 2023 09:46:36 AEDT ]]>