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Stable isotope analysis of δ15N and δ13C values allow us to interpret the effects of interspecific competition and environmental factors on fishes’ resource use. Saratoga Lake in Wyoming is one of the few locations brook stickleback Culaea inconstans (an invasive species), Iowa darter Etheostoma exile (a species of greatest conservation need), and fathead minnows Pimphales promelas are present. We used stable isotope signatures to investigate the trophic patterns of these species as well as catch rates over time. We sampled Saratoga Lake six times from June through September 2021. Fifteen individuals per species were harvested at each sampling event for stable isotope analysis and the remaining fish were identified, measured, and enumerated. Trends in δ13C data suggest that brook stickleback and fathead minnow exploited pelagic resources while Iowa darter primarily used littoral resources early in the season. However, brook stickleback and fathead minnow switched to use more littoral resources later in the season, coinciding with the timing of a cyanobacterial bloom. Iowa darter catch rate steadily declined over the season while fathead minnow and brook stickleback catch rates did not show directional trends. These results imply that changing habitat conditions and resource availability may potentially increase interspecific competition later in the season, with implications for fish species of greatest conservation need. Furthermore, our findings open the door to further investigation of the effects of cyanobacterial blooms on small-bodied fishes.

Plestiodon multivirgatus, commonly known as the many-lined skink, possesses a blue tail as a juvenile that it loses as it matures. The trait is believed to serve as a predator diversion tactic but this hypothesis has not been tested in this species. We used a clay model predation experiment to examine the effects of the trait on avian predation. We found that the presence of a blue tail significantly increased the average distance of avian attack towards the tail of the model and altered the distribution of attacks on the body and tail. Blue-tailed models were also found to be attacked less than black-tailed ones. These results suggest that the blue tails do serve to aid in evading predation, and additionally suggest an aposematic function as well. The second conclusion contradicts previous experiments examining similar traits, opening new avenues for future research into this understudied species.

Submitted in total fulfillment of the requirements for the degree of Doctor of Philosophy to the School of Agriculture, Biomedicine and Environment, La Trobe University, Victoria.

Typescript of: White, C.R., Marshall, D.J., Chown, S.L., Clusella-Trullas, S., Portugal, S.J., Franklin, C.E. & Seebacher, F. 2021. Geographical bias in physiological data limits predictions of global change impacts. Functional Ecology 35, 1572-1578.

Manuscript of: Kuyucu, A.C. & Chown, S.L. 2021 Time course of acclimation of critical thermal limits in two springtail species (Collembola). Journal of Insect Physiology 130, 104209.

Rabies is a zoonotic virus that is extremely lethal to humans and many wildlife species such as raccoons, skunks, foxes, as well as domestic animals such as cats, dogs, and livestock. Reservoirs of the rabies virus throughout species specific populations pose an enormous risk of exposure and infection of domestic animals that have direct contact with humans. The most effective way to prevent wildlife spillover of rabies is through the use of vaccine programs. The wildlife targeted with vaccines are mainly skunks, raccoons, and foxes since these species hold the most significant reservoirs of the virus within the United States. Modified live or attenuated vaccines and whole inactivated or killed vaccines will be discussed as well as their effectiveness and drawbacks. Different forms of administration of vaccines will be compared and contrasted to decide the effectiveness of the types. The social and habitual behaviors of skunks, raccoons, and foxes need to be understand in order to administrate the vaccines at the most effective time to ensure a larger number of wildlife are vaccinated. The cost effectiveness of type of vaccine, administrative methods, and the cost of distribution must be analyzed to reduce costs of the vaccine programs. Further research must be done to create different strains of vaccines that are cost effective, have very few drawbacks, and are effective at preventing the virus from infecting wildlife populations. It may not be possible to eradicate the rabies virus within the near future due to its ability to infect many species but the control and prevention of the virus in the wildlife populations is essential in order to reduce the risk of domestic animals being infected and ultimately prevent humans from becoming infected.

One of the largest issues currently in the agriculture sector is communication with the public. Farmers and ranchers have pride in the service they provide their fellow man but most consumers are so far removed from production that they may not understand or appreciate the service being provided. This disconnect between the producers and the consumers is proving to be problematic and potentially costly for both parties. Farmers and ranchers are being criticized for their practices but refuse to discuss what they are doing; consumers are doing the criticizing and may not necessarily be making "educated" choices. What is being done to change the public's perception of agriculture? This senior project takes a look at scientific studies that have measured information transfer, polls, public comments and discussions, personal experience through meetings and conventions, as well as looking at what agencies such as the National Pork Board and National Corn Growers Association are doing to address public concerns and questions. Awareness of the issue has been raised and information transfer is slowly improving, but is it enough? Adaptation is the key to survival, now consumers and producers must adapt and work together in order to understand the role they both play.

Manuscript for: Kovacevic, A., Latombe, G. & Chown, S.L. 2019. Rate dynamics of ectotherm responses to stress. Proceedings of the Royal Society B 286, 20190174.

As obesity rates continue to rise, it is important for us to understand the risks of health issues that are comorbid with obesity. Diseases associated with obesity are not only affecting the individual, but also their progeny. This research project attempts to show a correlation between maternal obesity, and first generation offspring's cardiovascular health risks. Using Rambouillet/Columbia cross ewes as a human biomedical model, we studied the developments of cardiovascular disease risk factors in advanced age (6-7 years old) female offspring born to over-nourished/obese mothers. Subjects were analyzed for their total body fat and total percent of lean mass. Data such as mean arterial pressure (MAP), and blood pressure (BP) were also recorded. We hypothesize that these first generation offspring (F1) will show a higher mean arterial blood pressure if subjected to maternal obesity (MO) in utero than if gestated by lean ewes fed only to requirements throughout pregnancy (control, C group).

An ovine model of over-nutrition during pregnancy is currently in development at the Center for the Study of Fetal Programming at the University of Wyoming. In 2007, an estimated 54.5% of women of childbearing age (20-39 years) are overweight or obese. This model examines the effects of maternal obesity on the health and lifespan of the offspring. Sheep were used to examine these health risks and effects, as fetal development sheep and humans is similar. In the sheep, the nutrient transfer site of the placenta is called a placentome, with both a fetal cotyledonary (COT) and a maternal caruncular component. Obese and control fed ewes were necropsied at day 135 of gestation and placentomes collected. The COT vascular bed of Type A placentomes from each ewe was perfused with a latex medium and the resulting vascular cast examined via a 3-D Scanning Electron Microscope. This allowed us to obtain an accurate measurement of COT vascularity to estimate group differences in blood flow and therefore nutrient transfer from maternal to fetal tissues. These data will be used to understand the impacts of maternal obesity on placental vascularity which may contribute to deprecating health effects of offspring later in life.

Data on the tethered flight of oriental fruit flies, Bactrocera dorsalis, in relation to age, sex and body mass at different temperatures.

In group-living animals social information is essential to survival, providing indirect information about the environment, such as predator presence. An individual’s ability to acquire social information is mediated by its sensory system. In visually-oriented species, different visual dimensions provide rapid information about conspecifics. However, we know relatively little about how the uptake of visual social information mediates the formation of coordinated patterns of group movement, referred to as collective behavior. Using two species of birds (i.e., European starling (Sturnus vulgaris) and red-winged blackbird (Agelaius phoeniceus)) and fish (i.e., zebrafish (Danio rerio) and golden shiner (Notemigonus crysoleucas)), I determine how the structure of social interactions are facilitated by the capabilities imposed by the visual system from a theoretical point of view. With a focus on zebrafish (Danio rerio), a visually-oriented, social cyprinid, I further explore the role of vision in mediating social interactions. Specifically, I characterize several relevant visual dimensions in zebrafish that have the potential to influence the uptake of social information: visual coverage, visual resolution and visual contrast. With insights gained from theoretical modelling and a series of behavioral experiments, I discuss the constraints that these visual dimensions might impose on social interactions and develop predictions for collective behavior.

This report summarises the outcomes of the Workshop on; prioritisation of species, identification of best-practice capture and handling, design of post-release survival (PRS) studies, and development of effective communication campaigns, for developing positive behavioural change in recreational fishing of Sharks and Rays.The main objective of the national workshop was to discuss adoption of best-practice techniques by the recreational fishing sector in order to improve outcomes for fishers and animals. The specific objectives of the workshop were to:1. Identify priority species (or groups) of chondrichthyans caught by recreational fishers for the development of best-practice capture and release guidelines and post-release survival studies.2. Develop and identify key messaging for safe capture and handling to include in best-practice guidelines.3. Identify key design aspects of PRS studies needed to assess, support and refine the proposed best-practice guidelines for recreational fishers.4. Assess the best ways to communicate and extend the guidelines to recreational fishers.5. Discuss approaches for monitoring and measuring behaviour change in recreational fisheries.

This thesis examines the role that moisture in the nest during development and hatchling energetics play in determining the ability of sea turtle hatchlings to crawl, swim and survive.

This thesis contains a review chapter outlining the microbiota of vertebrates and how this is influenced by phylogenetic history. The remaining chapters are focused on the microbiota of sea turtles and how it is affected by factors such as phylogeny and geography with implications for sea turtle health and physiology.

The American crocodile (Crocodylus acutus) is a common resident of Central American waterways, with one of the largest ranges of all crocodilians. It is very salt-tolerant, with only Nile crocodiles and Saltwater crocodiles superseding it in terms of being the most saline tolerant. Globally it has lost 9% of its range, with habitat destruction and fragmentation as the leading threat to this species. Overall there is a great need to understand the habitat uses by this species in order to mitigate consequences of further anthropogenic incursions along its range. Thus, this study aims to investigate seasonal effects of salinity on habitat selection of American crocodiles in a natural mangrove habitat, and to validate use of a commercial drone as a surveying tool for crocodilians in such habitats. This study found that as the seasons shift from wet to dry there was an associated increase in salinity of the estuarine waterway that resulted in an increase in the halocline of the estuary waters the greater the distance from the ocean. When broken down into the following groups: Hatchlings and juveniles (HJ) vs subadults and adults (SbA) it was found that salinity as well as season both had a correlation with the presence of crocodiles from the HJ group (p Surveys taken via drone were as efficacious as surveys taken diurnally via boat, with a survey encounter rate of 0.40 km-1, but still less efficacious than nocturnal eyeshine surveys, which had an encounter rate between 1.2 – 2.9 km-1. The drone was able to identify animals that were submerged under water, but was unable to ID animals resting on banks in thick mangroves. However, the drone was able to identify crocodiles as small as 0.7m. Further, the drone showed encounter rates for sharks and rays that were much higher than crocodiles, 0.84km-1 and 0.64km-1 respectively.

The koala, Phascolarctos cinereus, is a seasonal breeder and the females are capable of producing one young each year. However, in many koala populations fertility among females is low. The aim of this study was to investigate the causes of low reproductive success in female koalas, and to suggest procedures for the management of populations with low fertility. The main study was conducted between 1982 and 1984 on two island populations in Western Port Bay, Victoria. One on French Island had a high rate of reproductive success and the other, on Phillip Island had a low rate of reproductive success. Additional data were collected from a population in the Brisbane Ranges National Park, Victoria. A correlation was established between habitat and low reproductive success. On Phillip Island a sub-population of koalas feeding exclusively on Eucalyptus globulus foliage had the lowest reproductive success. Animals feeding on E.viminalis and E.ovata had the highest reproductive success, and the fertility of animals feeding on a mixture of the three species was intermediate.

As ectothermic marine megafauna, sea turtle physiology and ecology are tightly intertwined with temperature, seasonality, and oceanography. Identifying how turtles respond when exposed to cold water, how they adapt to cold environments when they need to explore cold environments in order to forage, and what foraging resources are exploited by sea turtles are all components central to their conservation. Cold-stunning is a well-documented phenomenon that occurs when water induced decreases in sea turtle body temperature cause turtles to become immobilized and wash ashore. While most cold-stunned turtles are rescued and rehabilitated, we do not know whether cold-stunning is an acute transient occurrence, or a symptom of a bigger environmental problem. Further, while in some environments avoiding cold water is preferential, in other habitats, sea turtles need to inhabit cold environments in order to forage. Along the Eastern Pacific Rim, discrete upwelling locations are characterized by high primary productivity and unusually cold water. In these environments, avoidance is not possible and sea turtles require physiological adaptions to mitigate body temperature decreases in cold water. Little is known about how turtles handle upwelling environments, despite the fact that sea turtles remain in these habitats regardless of water temperature fluctuations. Because upwelling habitats provide increased nutrient presence, and sea turtles are opportunistic foragers, quantification of diet composition will further our understanding of why sea turtles remain in cold water environments year-round. Diet composition in multiple populations of cohabitating sea turtles revealed partitioning that results in reduced inter-specific competition. Further, flexibility in diets provides a wide range of ecosystem services central to habitat resiliency. Therefore, conservation of endangered sea turtles requires complete ecosystem conservation, and complete understanding of the interconnectivity of sea turtles and their environments is crucial.

Lecture given by Professor Emeritus Frederick D. Provenza, Dept. of Wildland Resources, Quinney College of Natural Resources, Utah State University, at the Waite Campus, University of Adelaide, 3.4.1992This lecture is part of the Campus Seminars and Distinguished Lecturer Series, Waite Campus, University of Adelaide, 1991 – 1997. https://figshare.com/projects/Campus_Seminars_and_Distinguished_Lecturer_Series_Waite_Campus_University_of_Adelaide/17756

Lecture given by Professor Peter Parsons, former Professor of Genetics, La Trobe University at the Waite Campus, University of Adelaide, 8.5.1992.This lecture is part of the Campus Seminars and Distinguished Lecturer Series, Waite Campus, University of Adelaide, 1991 – 1997. https://figshare.com/projects/Campus_Seminars_and_Distinguished_Lecturer_Series_Waite_Campus_University_of_Adelaide/17756