Current research on reproductive ecology examines maternal & paternal reproductive investment and the subsequent impact on offspring characteristics and fitness. Broadly ‘what the parents contribute or control and how this shapes offspring phenotypes’.
Reproductive research also includes how environmental factors (e.g. temperature, humidity, pollutants) and/or parental factors (e.g. diet, body condition, behaviour) shape maternal/paternal allocation strategies.
The group also has an applied focus to conservation biology with research on endangered species, captive breeding, reintroduction and the impacts of anthropogenic disturbance.
The group uses a multidiscipline approach to question orientated research utilising a diverse range of taxa, including but not limited to reptiles, birds, bats and marsupials.
Supervision of research projects on any aspect of conservation biology, endangered species, reproductive ecology and/or evolutionary biology of reproduction will be considered. Projects specific to current research interests are offered annually and interested students should contact Dr Robert directly.
Understanding the mechanisms and adaptive advantage of sex allocation
Sex allocation theory predicts parents should bias their investment into the offspring sex that maximises their fitness. Current theories aim to explain adaptive adjustments in offspring sex ratios and have provided some compelling examples. However, offspring sex ratios in many taxa (especially mammals) have proven difficult to understand and would be better facilitated by a mechanistic understanding. Our research has been focused on unravelling mechanistic underpinnings of adaptive sex allocation from paternal contribution in ejaculate to maternal condition at the time of conception and the role of sex steroid and glucocorticoid hormones. Some of our research utilises the unique ability to access marsupial pouch young as neonate equivalents in-utero to test the adaptive advantage of raising one sex over the other through cross-fostering offspring prior to any significant maternal contribution.
Ecological impacts of artificial lighting on wildlife
Artificial lighting has fundamentally changed the earth’s night-time environment, with a wide range of biological effects on animals. Over billions of years organisms have evolved to respond to natural light cues to control or modulate behaviour, activity, reproductive timing and physiological function. Our research has focused on seasonally breeding wildlife to document the impact of artificial light on the timing of reproduction. We are working with industry partners to develop and test wildlife friendly lighting options using our current knowledge of the visual and non-visual sensitivities of our target species with LED lights that combine custom wavelengths to mitigate the negative effects of light at night.
Captive breeding and reintroduction biology
Captive breeding is one aspect of threatened species conservation, however attempting to breed and raise species in captivity presents many challenges for recovery programs. Captivity results in various environmental modifications that can lead to behavioural, morphological and physiological changes that result in potentially detrimental effects upon reintroduction. Some of our research has focussed on maternal mate choice to improve both conception rates and offspring fitness in captive breeding programs. While other research is assessing predator recognition, behavioural, personality and cognitive traits linked to survival success post release. The choice of candidates for release is often based on age, sex and health status, however, there is growing recognition that an individual’s behavioural type is related to fitness and hence may be important to survival success. The study of behavioural traits has been used in wildlife to assess the suitability of individuals for captive environments, but less utilised for the selection of candidates for release. While the existence of different personality traits within and between animal populations has been relatively well studied, the applied application of this variation to reintroduction programs has been neglected. If captive populations are to effectively act as insurance and source populations for threatened species, they must retain essential behaviours for survival.
Climate change and physiological impacts of extreme weather events
Current climate change scenarios for southern Australia predict mean temperatures to rise 2.7 – 4.2°C by 2090. Increased maximum temperatures, higher frequency of hot days and longer duration of heat waves are already being observed. Despite this, the consequences of climate warming are poorly understood for many organisms. Our work in this field includes the energetic costs of thermoregulation by little penguin during extreme weather events, the thermal biology of artificial roosts for hollow dependant fauna, and the impact of thermal extremes during gestation in viviparous reptiles.