Michael Mahony and John Clulow with great barred frog. Photo: ABC News 2013
Overview of our research projects and directions
Our research is centred on Conservation Biology. Most of our interest and expertise is with amphibians, but we also have projects that work on ecosystems and other animal groups such as monotremes (platypus), microbats, macroinvertebrates, birds, and the impact of invasive species.
Being Conservation Biologists requires that we often multidisciplinary in our approach and the breadth of our research projects reflect this diversity.analysis to understand the role of behaviour in habitat use/choice. Life stage specific behavioural patterns and avoidance of predators.
1. Building sound restoration strategies for endangered amphibians
Objective: to prevent the decline of endangered amphibian populations and to develop strategies that will enable mitigation of impacts. While we focus on a single species we consider that many of the research understandings are applicable to most amphibian species and the major causes of decline.
a. Model animal: Endangered green and golden bell frog (Litoria aurea).
b. Study sites: Sydney Olympic Park, Kooragang Island; New Zealand; Broughton Island
c. Distributional studies: focused mainly in the Hunter and Central Coast regions on NSW.
d. Disease epidemiology: Impacts of chytrid fungus on extant field populations. Role of population density, age/stage –class structure, intraspecific and interspecific interactions on prevalence and infection loads.
e. Population Demography: PVA, vital rates and models of mortality and survivorship.
f. Restoration ecology: habitat construction and enhancement involving habitat facilitation to promote persistence in the face of chytrid infection. Use of naturally occurring saline influences to promote frog persistence.
g. Impact of invasive species: Specifically the role of Gambusia in reducing occupancy and population abundance. Management strategies.
h. Behavioural ecology: conspecific attraction and occupancy along with habitat analysis to understand the role of behaviour in habitat use/choice. Life stage specific behavioural patterns and avoidance of predators.
2. Assisted Reproductive Technologies
Objective: to provide the necessary technologies to enable an effective genome bank for endangered amphibians.
a. Model animal: We have worked on creating laboratory colonies to act as a model for a range of investigations. Tree frogs: Litoria aurea, Lit fallax, Lit revelata; Ground frogs: Limnodynastes peroni, Lim tasmaniensis, Mixophyes fasciolatus, Mixophyes iterates.
b. Primary investigations:
i. Hormonal Induction of gamete release (sperm and egg).
ii. Non-invasive collection of gametes.
iii. Activation and inactivation of sperm.
iv. Cryopreservation of gametes and embryos (including totipotent embryonic cells)
v. IVF procedures.
vi. Development of ART techniques: Somatic cell nuclear transfer (SCNT); intracytoplasmic sperm injection (ICSI; enucleation of recipient eggs; Androgenesis, polyploidy.
c. Current ART Projects:
i. Litoria aurea (captive husbandry, IVF)
ii. Rheobatrachus silus (Lazarus project, SCNT, ICSI)
iii. Mixophyes fasciolatus and Mix balbus (Lazarus project, SCNT, ICSI; captive husbandry)
iv. Litoria littlejohni (captive husbandry, IVF, cryopreservation of sperm and embryonic cells)
v. Philoria sphagnicolus, richmondensis and kundagungan (captive husbandry, IVF, cryopreservation of sperm and embryonic cells)
vi. Assa darlingtoni (captive husbandry, IVF, cryopreservation of sperm and embryonic cells, reproductive behaviour)
vii. Heleioporus australiacus (captive husbandry, IVF, cryopreservation of sperm and embryonic cells)
viii. Uperoleia (Oyster Cove species) (captive husbandry, IVF, cryopreservation of sperm and embryonic cells)
ix. Pseudophyrne australis and coriacae (captive husbandry, IVF, cryopreservation of sperm and embryonic cells)
Major Partners: Australian Research Council. South Australian Museum. University of NSW, Monash University. NSW OEH Dr Karen Thumm.
3. Climate change impacts on endemic frogs of the Gondwana Rainforest of Australia World Heritage Area
Objective: To investigate the potential impact of climate change scenarios on the endemic frogs of the GRAWHA.
a. Target species: Assa darlingtoni, Philoria sphagnicola, P kundagungan, P. loveridgei, P. pughi, and P. richmondensis.
b. Methods: Correlative models of fundamental niche under current climate and future climate scenarios. Mechanistic physiological models of species climatic niche. Phenology of breeding behaviour and its relationship to climate variables. Phylogenetics of isolated populations.
Major Partners: Commonwealth Department of the Environment (Caring for Country grant); NSW National Parks and Wildlife Service; Queensland National Parks; Southern Cross University; Griffith University; South Australian Museum.
4. Polyploidy in amphibians and its evolutionary significance
Objective: to understand the fundamental role of genome duplication in the evolution of the vertebrates.
a. Model animal: Species of the genus Neobatrachus
b. Primary investigations: Testing of the alternate hypotheses of origin – autopolyploid or allopolyploidy. Laboratory test using cross species hybrid combinations and hat shock techniques for auto polyploidy. Species identification. Natural hybridisation and backcrossing. Reticulate evolution. Nucleolar organiser region duplication and functioning. Mating call structure in hybrids and autopolyploids.
Major Partners: South Australian Museum. University of Wursburg Prof Michael Schmid.
5. Australia’s vanishing frogs
Objective: This project involves long-term monitoring of a series of study sites along the north east coast and tablelands of NSW to provide information on amphibian population distribution and abundance. It is the longest intensive and extensive monitoring or a group of species that have a high risk assessment for decline due to the amphibian disease chytridiomycosis. This project also includes a significant component of citizen science by involving volunteers organised in partnership with Earthwatch.
a. Methods: Population monitoring and population demography using occupancy modelling and mark-recapture techniques.
b. Assessment of chytrid prevalence and infection levels.
c. Involvement: We have conducted replicated field surveys in the period 1996 to 2013, and in that time over 300 volunteers have worked on the project and 12 doctoral and honours students have been introduced to the important role and contribution of citizen science. Our teams are in the field for two or one week and have included adults, students and families.
Major Partner: Earthwatch.
6. Governance and Policy
Objective: We recognise that as conservation biologists we need to share our findings widely to benefit the animals and ecosystems and evolutionary processes that we strive to protect. This often involves preparation of policy documents, conduct of workshops, review and comment of public policy documents, and review and comments on EIS and EIA documents for major developments.