Vietnamese soy sauce has been made for centuries using traditional methods, in villages in Northern Vietnam. This sauce differs from other Asian products not only in its raw materials but also in its flavour characteristics. Presently small scale Vietnamese soy sauce is produced mostly with a standardised inoculum of Aspergillus oryzae under natural conditions. This usually gives rise to a product of variable and inconsistent quality. The aim of this study was to standardise the fermentation condition for the production of Vietnamese soy sauce, so as to obtain a product of more consistently good quality. Aspergillus flavus var columnaris was used as the inoculum. The inoculum was prepared by growing the organism on sticky rice at 20 and 37 degrees centigrade under aerobic conditions. At 20C, a high protease activity was recorded in the inoculum while at 37C, a high amylase activity was observed. The two different inocula prepared at 20C and 37C were then used in the preparation of soy sauce in the normal manner. The inocula were mixed with cooked roasted soy beans and salt water, left to age for 1 month at 30C, followed by ageing at 20C for 2 months. The products obtained were subjected to sensory evaluation and analysed for glucose, fructose, amino acids, nitrogen, ethanol and NaCI. Both inocula produced products of acceptable quality. The inoculum produced at 20C had a higher sensory evaluation score. It also contained a higher level of protein (14.5% compared to 11%), and a higher sensory evaluation score (6.9 compared to 3.2) when compared to a commercial Vietnamese sauce, Hanoi soy sauce. This valuable information will now enable small scale producers to produce this product throughout the year by controlling the temperature, and not be limited to the summer season, as has been the case with the traditional method of production. / Master of Science (Hons)

I studied aspects of the ecology of the Murray River turtle, Emydura macquarii, to determine the impact of the introduced red fox, Vulpes vulpes. The fox is one of Australia's worst vertebrate pests through its predation on livestock and native mammals, but their impact on reptilian communities is not known. I conducted a large-scale mark-recapture study to evaluate population growth of E. macquarii in the Albury region of the upper Murray River by determining growth, reproduction and survival. The study was conducted downstream of the first, and largest, impoundment on the Murray River, Lake Hume. Emydura macquarii predominantly inhabit the lagoons in the upper Murray River, as the mainstream and Lake are possibly too cool to maintain metabolic processes. They are easily captured in hoop traps and the use of live decoys maximises trap success. Over 2000 hatchling turtles were marked and released into two lagoons between January 1997 and January 1998. Growth of these individuals is rapid over the first few years but declines towards maturity, and is indeterminate after maturity. Although growth annuli are not well defined, even on young individuals, the von Bertalanffy model describes the growth of both male and female E. macquarii. Male turtles mature at 5-6 years and females mature at 10-12 years. Female turtles may maximise reproductive potential by delaying maturity and producing one relatively large clutch (mean = 21 eggs) per year, which is positively correlated with body size (PL). Although primarily related to body size, clutch size varies annually because of environmental conditions. If winter and summer rainfalls are below average and temperatures are above average, E. macquarii may reduce clutch size to increase the chance of the eggs surviving. Nesting predominantly occurs during the first major rain-bearing depression in November. Habitat variables, including distance from water, nearest nest, and tree, and soil type were measured for each nest to determine characteristics that attract predators. Nests close to the shoreline and trees are heavily preyed on, and nests constructed in sand are less likely to be destroyed by predators. Foxes detect nests through a combination of chemical cues from eggs and slight soil disturbances, whereas birds only destroy nests observed being constructed during the day. Female turtles alter nesting behaviour and construct nests much further away from water when foxes were removed and as a result, nests are less dense and away from trees. Thus in high predation risk areas, turtles minimise emergence and search times to reduce the risk of direct predation by foxes. Predation is reduced when nests are in lower densities and away from trees, because predators increase search efforts when nests are in higher densities and birds are more likely to destroy nests close to trees. Reproductive success is further reduced in high predation risk areas because more nests are constructed in sandy substrates where clutch success is reduced compared to incubation in more dense substrates. Where predators are a significant source of mortality, prey may use indirect methods, such as chemical recognition, to avoid encounters. Nesting turtles did not avoid areas where fox odour was present, suggesting that they assess predation pressure from foxes by other mechanisms, such as visual recognition. However, an innate response occurs to the odour of a once common predator on the Murray River, the eastern quoll (Dasyurus viverrinus), whereby turtles recognise and avoid nesting in areas where quoll odour is present. Therefore nesting turtles show a similar avoidance response to two different predators, using different mechanisms of detection. Similarly, predation risk may influence hatching times and nest emergence. The rate of embryonic development of E. macquarii may increase or eggs may hatch early so that the clutch hatches synchronously, thereby reducing the risk of predation through group emergence from the nest. Emydura macquarii reach densities of over 100 turtles.ha-1, with the majority of the population consisting of sexually mature individuals. Emydura macquarii has a Type III survival curve where mortality is extremely high in the egg stage (93% nest predation), remaining high over the hatchling stage (minimum survival rate- 10%), but decreasing rapidly throughout the juvenile stage (~70% juvenile survival). Adult survival is extremely high, with greater than 95% of adults surviving each year. Foxes through nest predation cause most mortality but a small proportion (~3%) of nesting adult females are killed by foxes each year. A removal program evaluated the impact of foxes. In 1996, fox numbers were monitored around four lagoons by spotlighting and non-toxic bait uptake. Foxes were removed from around two of the lagoons throughout 1997 and 1998, using spotlight shooting and 1080 bait poisoning. Fox numbers were continually monitored around all four lagoons during the study. Nest predation rates remained around 90% in all sites where foxes were present, but fell to less than 50% when foxes were removed. At the same time, predation on nesting female turtles was eliminated where foxes were removed. Demographic models using staged based survival schedules, together with growth and fecundity values for E. macquarii show a decline of 4% per year in these populations. Elasticity analyses shows that survival of adult female E. macquarii has the major influence on population stability and a reduction of nest predation alone is unlikely to address the population decline. Management options, such as reducing foxes prior to nesting around key lagoons, will stabilise the population decline, and eliminating foxes completely from certain areas with high dispersal potential, will promote recruitment of juvenile E. macquarii.

Tuatara (Sphenodon spp.) were once widespread over both the North and the South Islands of New Zealand approximately 1000 years ago but are now restricted to offshore islands due to introduced predators and habitat destruction. The survival of tuatara is now threatened by climate change because of isolation on islands that prevent them from migrating to cooler regions, and by their limited capacity to adapt due to their long life span and low genetic diversity. The thermal suitability of cooler regions for future translocations could be the key for tuatara conservation. The overall aim of the study was to determine the effect of cool temperature on the physiology, behaviour and egg incubation of Cook Strait tuatara (Sphenodon punctatus). As well answering specific questions about tuatara and their adaptation to cool temperature this study aimed at answering general questions about the behavioural and evolutionary ecology of reptiles. I first compared the preferred body temperature, feeding responses and tolerance to cold temperature of tuatara (Sphenodon punctatus) with three lizard species that inhabit the Otago region of southern New Zealand: Hoplodactylus maculatus, Naultinus gemmeus and Oligosoma maccanni. As well as testing the co-adaptation hypothesis between preferred body temperature and physiological performance of reptiles, I wanted to determine whether tuatara (which are planned to be reintroduced from a warmer site to the Otago region) have similar responses to cool temperature as do Otago lizard species. I found that tuatara show responses to cold temperatures similar to those of lizards from southern New Zealand, suggesting that if tuatara are translocated outside of their geographical range, they are likely to survive. I then tested if tuatara were capable of modifying their thermoregulatory behaviour if translocated to a cooler region. To do so, I conducted a laboratory experiment in which tuatara were provided with three thermal treatments corresponding to the thermal environments they would experience in their current habitat and the proposed reintroduction site. Contrary to the prediction of the cost-benefit model of thermoregulation, tuatara became active thermoregulators when the thermal quality of the habitat decreased. The results suggest that the model is less applicable to cold-adapted species and that if translocated to cooler regions, tuatara will be able to adjust their thermoregulatory behaviour to their thermal environment. Tuatara are temperature-dependent sex determination (TSD) reptiles and their translocation to cooler regions could have an dramatic impact on the sex ratio of new populations. To determine if potentially lower incubation temperature would be a limiting factor for the reintroduction of tuatara, I translocated eggs to the proposed reintroduction site. Some tuatara embryos developed at the site (and later hatched in the laboratory), but incubation lasted longer than in natural nests and all hatchlings were female. This trend observed in biased sex ratio might change in the context of climate change as an increase of soil temperature by 3�C would allow the production of males at the proposed site. The present study demonstrates that the translocation of tuatara further south, outside of their current geographical range, is possible and recommended. Tuatara show similar responses to cool temperatures compared with lizards that live in southern New Zealand, they can also adjust their thermoregulatory behaviour if translocated to cooler habitats, and tuatara embryos could potentially develop successfully in cooler regions. The greatest chance for the future survival of tuatara and TSD species in general, lies in translocation to other locations that are thermally suitable.

Cette étude est consacrée à la caractérisation de la migration de l'uranium dans une zone restreinte du site du Bouchet, ancienne usine de traitement de minerai d'uranium, aujourd'hui démantelé et en cours de réhabilitation. Certains déchets de cette usine ont été stockés dans une déposante réhabilitée à proximité, appelée le site d'Itteville. Dans le cadre de la surveillance de l'environnement autour de la déposante (air, eau, sédiment) imposée par arrêtés préfectoraux, un piézomètre (PZPK) situé à l'aval hydraulique de cette dernière, présente des pics d'uranium dissous total chaque hiver depuis les années 1990. Le PZPK collecte à la fois les eaux d'une formation tourbeuse calcique, saturée en eau, située entre la surface et 3 m, ainsi que l'eau d'une nappe alluviale vers 6 m de profondeur. Dans un premier temps, une caractérisation hydrogéochimique du site a mis en évidence le terme source d'uranium, qui se trouve dans la tourbe vers 0,8 m, écartant ainsi toute fuite provenant de la déposante. En effet, quelques microparticules d'oxyde d'uranium et d'oxyde mixte d'uranium-thorium ont été détectées, mais ne constituent pas la partie majeure du terme source. Dans un second temps, la chimie des eaux de tourbe et du PZPK a fait l'objet d'un suivi bimestriel de 2004 à 2007 permettant de comprendre les raisons des fluctuations saisonnières de [U]tot.diss.. Complétées par des modélisations géochimiques et une identification bactérienne par analyse de l'ADN 16S, les chroniques de chimie de l'eau ont mis en évidence une activité bactérienne sulfato-réductrice importante en été, entraînant des conditions plus réductrices et donc, une teneur en uranium dissous total limitée par la faible solubilité de l'uraninite UIVO2(s). En hiver, cette activité bactérienne étant minime et la pluviométrie efficace plus importante, les conditions sont plus oxydantes favorisant la forme U(VI), plus soluble, notamment sous la forme du complexe Ca2UO2(CO3)3(aq) mis en évidence par SLRT. Enfin, l'activité bactérienne sulfato-réductrice a été reproduite en laboratoire afin de mieux caractériser son impact sur la solubilité de l'uranium dans la tourbe. Divers paramètres ont été étudiés (sources de C, température, nutriments) afin de recréer des conditions à la fois proches et aussi éloignées de celles in situ. Les identifications bactériennes par analyse de l'ADN 16S, en fonction du temps d'incubation, ont confirmé une augmentation de la proportion des bactéries sulfato-réductrices. Parallèlement, la chimie de l'eau, ainsi que des calculs géochimiques et des observations MEB et analyses XANES, ont mis en évidence une diminution de [U]tot.diss., due à sa réduction en UO2(s) (certainement sous forme de nanoparticules). Bien que le mécanisme réactionnel n'ait pu être déterminé, à savoir biotique (réduction directe de U par les bactéries) ou abiotique (réduction indirecte), ces expériences ont montré que les bactéries sulfato-réductrices peuvent prévaloir au sein d'une population autochtone variée dans des conditions proches de celles in situ. De plus, la tourbe calcique étudiée contient un stock important de weddellite (CaC2O4.2H2O(s)), constituant un apport permanent d'ions oxalate C2O42- qui peuvent être utilisés comme source de C lors de la réduction des ions sulfate et/ou uranium en été.

Conserving the environment is an issue that is gaining popularity day by day. Phosphorus transfer from agricultural soils is an important environmental issue that is being closely observed as the transport of phosphorous to water bodies is adversely affecting water quality due to accelerated eutrophication. It is important to establish phosphorous models that accurately account for soil test phosphorous. Standard models like SWAT (Soil and Water Assessment Tool) and EPIC (Environmental Policy Integrated Climate) were designed for serving this purpose. They are now used as the basis for developing new models that can more accurately account for the phosphorus transport, depending on local soil conditions and external factors like climate, addition of biochar or other soil amendments. Our research involved development of new methods from published data that are applied to different soils from Kentucky that are incubated for various time periods, with and without the addition of biochar amendments. Changes in the soil labile phosphorus content after phosphorus addition to and depletion from these incubated soils was measured to discern the effect of biochar on the rates of phosphorus transport. The measured labile phosphorus was further analyzed using statistical analysis software drawing comparisons among treatments without biochar, with low temperature biochar and high temperature biochar for specific soil-biochar combinations. Loamy sand soils with both pine chips and switch grass biochar types have shown slightly increased leeching of phosphorus upon addition of biochar whereas clay loam soils have not shown any significant change upon addition of biochar.

Low molecular weight organic acids (LMWOAs) are important nutrients for microbes. However, most LMWOAs do not exist freely in the environment but are bound to macromolecular organic matter, e.g. kerogen, lignite and coal. During burial and geological maturation of sedimentary macromolecular organic matter biological and abiological processes promote the liberation of LMWOAs into the surrounding sediment. Through this process, microbes in sedimentary subsurface environments are supplied with essential nutrients. To estimate the feedstock potential of buried macromolecular organic matter to many environments it is important to determine the amount of LMWOAs that are bound to such a matrix. However, high-pressure and high temperature are a key feature of deep subsurface environments, and these physical parameters have a profound influence on chemical reaction kinetics. Therefore it is essential for the estimation of the feedstock potential to generate high-pressure and high temperature for the liberation of LMWOAs to recreate true in-situ conditions. This work presents a newly developed, inexpensive incubation system for biological and geological samples. It allows the application of high-pressure and high temperature as well as a subsampling of the liquid phase without loss of pressure, thereby not disturbing the on-going processes. When simulating the liberation of LMWOAs from sedimentary organic matter, the newly developed incubation system produces more realistic results than other extraction systems like Soxhlet. The extraction products remain in the extraction medium throughout the extraction, influencing the chemical conditions of the extraction medium. Sub-bituminous coal samples from New Zealand as well as lignite samples from Germany were extracted at elevated temperature (90˚C) and pressure (5 MPa). The main LMWOAs released from these low rank coals were formate, acetate and oxalate. Extraction efficiency was increased by two to four times for formate, acetate and oxalate in comparison to existing extraction methods without pressurisation and with demineralised water. This shows the importance of pressure for the simulation of true in-situ conditions and suggests that the amount of bioavailable LMWOAs is higher than previously thought. With the increase in carbon capture and storage (CCS) and the enhanced recovery of oil and gas (EOR/EGR), more and more CO2 becomes injected into the underground. However, the effects of elevated concentrations of carbon dioxide on sedimentary organic matter are rarely investigated. As the incuabtion system allows the manipulation of the composition and partial pressure of dissolved gasses, the effect of highly gas-enriched (CO2, CO2/SO2, CO2/NO2; to simulate flue gas conditions) waters on the extraction yield of LMWOAs from macromolecular organic matter was evaluated. For sub-bituminous coal the concentrations of all LMWAOs decreased upon the addition of gas, irrespective of its composition, whereas for lignite formate always and acetate mostly increased, while oxalate decreased. This suggests an positive effect on the nutrient supply for the subsurface microbiota of lignite layers, as formate and acetate are the most common LMWOAs used for microbial metabolism. In terrestrial mud volcanoes (TMVs), sedimentary material is rapidly ascending from great depth to the surface. Therefore LMWOAs that were produced from buried macromolecular organic matter at depth are also brought up to the surface, and fuel heterotrophic microbial ecosystems at the surface. TMVs represent geochemically and microbiologically diverse habitats, which are supplied with organic substrates and electron acceptors from deep-seated hydrocarbon-generating systems and intersected shallow aquifers, respectively. The main electron donor in TMVs in Azerbaijan is sulphate, and microbial sulphate reduction leads to the production of a wide range of reduced sulphur species that are key players in several biological processes. In our study we estimated the effect of LMWOAs on the sulphur metabolising activity of microorganims in TMVs from Azerbaijan. The addition of a mixture of volatile fatty acids containing acetate and other LMWOAs showed significant positive response to the sulphate reduction rate (SRR) of samples of several mud volcanoes. Further investigations on the temperature dependency of the SRR and the characterisation of thermophilic sulphate-reducing bacteria (SRB) showed a connection between the deep hot subsurface and the surface. / Niedermolekulare organische Säuren (nachfolgend als LMWOAs - low molecular weight organic acids - bezeichnet) stellen wichtige mikrobielle Substrate dar. Jedoch liegen die meisten LMWOAs nicht in freier, bioverfügbarer Form vor, sondern sind vielmehr an hochmolekulare organische Substanzen gebunden, z.B. Kerogen, Lignit und Kohle. Während der geologischen Verbringung in tiefe Erdschichten und der geologischen Reifung von sedimentären hochmolekularen organischen Substanzen, führen biologische und abiologische Prozesse zu einer Freisetzung von LMWOAs in die umgebenden Sedimente. Durch diesen Prozess werden Mikroorganismen in unterirdischen sedimentären Ökosystemen mit essentiellen Nährstoffen versorgt. Um das Nährstoffpotential tief liegender hochmolekularer organischer Substanzen für diverse Ökosystemen abschätzen zu können, ist es notwendig, die Menge an LMWOAs, die an solch eine hochmolekulare Matrix gebunden ist, zu bestimmen. Dabei stellen hoher Druck sowie hohe Temperatur entscheidende Faktoren in tiefen unterirdischen Ökosystemen dar, welche einen signifikanten Einfluss auf chemische Reaktionen haben. Daher ist es für die Abschätzung des Nährstoffpotentials entscheidend, hohen Druck und hohe Temperatur bei der Freisetzung von LMWOAs zu erzeugen, um wahre in situ Bedingungen zu schaffen. In der vorliegenden Arbeit wird ein neu entwickeltes, preiswertes Inkubationssystem für biologische und geologische Proben präsentiert. Es erlaubt die Verwendung von hohem Druck als auch hoher Temperatur sowie eine Unterprobennahme der flüssigen Phase ohne Druckverlust, um den fortlaufende Prozess nicht zu unterbrechen. Bei der Simulierung der Freisetzung von LMWOAs aus sedimentären organischen Substanzen erhält man mit dem neu entwickelten Inkubationssystem realistischere Resultate als mit anderen Extraktionssystemen, wie z.B. eine Soxhlet-Apparatur. Die Extraktionsprodukte verbleiben während der Extraktion im Extraktionsmedium, wodurch die chemischen Bedingungen verändert werden. Kohleproben aus Neuseeland sowie aus Deutschland wurden mittels erhöhter Temperatur (90°C) und Druck (5 MPa) extrahiert. Die wichtigsten LMWOAs, die aus diesen Kohlen freigesetzt wurden, waren Formiat, Acetat und Oxalat. Die Extraktionseffizienz für diese LMWOAs konnte im Vergleich zu existierenden Extraktionsmethoden ohne Druck um den Faktor 2 bis 4 gesteigert werden. Dies zeigt die Bedeutung von Druck bei der Simulation von in situ Bedingungen und legt nahe, dass die Menge an bioverfügbaren LMWOAs größer ist als bisher angenommen. Durch die Zunahme der CO2-Speicherung im Untergrund (carbon capture and storage, CCS) sowie der erweiterten Förderung von Öl und Gas (enhanced recovery of oil and gas, EOR/EGR) wird immer mehr CO2 in den Untergrund gepresst. Jedoch sind die Auswirkungen von erhöhten CO2-Konzentrationen auf sedimentäre organische Materie noch unerforscht. Da mit dem Inkubationssystem die Veränderung der Zusammensetzung und des Partialdruckes von gelösten Gasen möglich ist, wurde der Effekt von hoch mit Gasen (CO2, CO2/SO2, CO2/NO2; um Kraftwerksabgase zu simulieren) angereicherten Wässern auf die Extraktionsausbeute von LMWOAs untersucht. Bei der subbituminösen Kohle zeigte sich eine Abnahme aller LMWOAs-Konzentrationen durch die Lösung von Gas im Extraktionsmedium, wobei die Art des Gases keine Rolle spielte. Bei Lignit konnte hingegen festgestellt werden, dass die Extraktionsausbeute an Formiat immer und an Acetat meistens erhöht wurde, während sie sich bei Oxalat verringerte. Dies deutet auf einen positiven Effekt für die Nährstoffversorgung von Mikroorganismen um Lignit-Lagerstätten an, da Formiat und Acetat die am häufigsten verwendeten LMWOAs im mikrobiellen Stoffwechsel darstellen. In terrestrischen Schlammvulkanen (terrestrial mud volcanoes, TMVs) steigt sedimentäres Material aus großen Tiefen an die Erdoberfläche. Somit werden auch LMWOAs, welche aus hochmolekularen organischen Substanzen freigesetzt werden, an die Oberfläche verbracht, und ermöglichen dort heterotrophe Ökosysteme. TMVs stellen dabei geochemisch und mikrobiell unterschiedliche Habitate dar, welche mit organischen Substraten und Elektronenakzeptoren aus tief liegenden, Kohlenwasserstoffe erzeugenden Systemen versorgt werden. In TMVs in Aserbaidschan stellt Sulfat den Hauptelektronenakzeptor dar, wobei mikrobielle Sulfatreduktion zu einer Vielzahl an reduzierten Schwefelspezies führt. In der vorliegenden Arbeit wurde der Effekt von LMWOAs auf die Aktivität von Mikroorganismen bei der Umsetzung von Schwefel in TMVs in Aserbaidschan untersucht. Die Zugabe einer Mischung verschiedener kurzkettiger Fettsäuren zu Schlammproben verschiedener TMVs erzeugte eine signifikant positive Reaktion in Bezug auf die Sulfat-Reduktionsraten. Weiterführende Untersuchungen zur Temperaturabhängigkeit der Sulfat-Reduktionsraten und die Charakterisierung thermophiler, Sulfat-Reduzierender Bakterien zeigte eine Verbindung zwischen der tiefen, heißen Biosphäre und der Erdoberfläche auf.

Nicotine Addiction is a chronic relapsing disorder. Relapse risk persists despite years of abstinence. Drug-associated cues have been demonstrated to induce craving and provoke relapse. Surprisingly, in human smokers, craving for nicotine increases or “incubates” with longer abstinence durations, a phenomenon that may explain persistent relapse liability. This incubation phenomenon also presents in animals trained to intravenously self-administer nicotine though the underlying mechanisms are unclear. Two proteins, ERK (Extra-cellular signal Regulated Kinase) and CREB (cAMP Response Element Binding protein) play important roles in learning, memory, and numerous aspects of drug addiction. We therefore examined whether changes in these proteins are associated with incubation of craving for nicotine in rats. We found increased nicotine-seeking behaviour after 14 days of abstinence (compared to 1 day) along with elevated ERK and CREB activity in the Accumbens brain region suggesting that these proteins may be involved in the incubation phenomenon.

Nicotine Addiction is a chronic relapsing disorder. Relapse risk persists despite years of abstinence. Drug-associated cues have been demonstrated to induce craving and provoke relapse. Surprisingly, in human smokers, craving for nicotine increases or “incubates” with longer abstinence durations, a phenomenon that may explain persistent relapse liability. This incubation phenomenon also presents in animals trained to intravenously self-administer nicotine though the underlying mechanisms are unclear. Two proteins, ERK (Extra-cellular signal Regulated Kinase) and CREB (cAMP Response Element Binding protein) play important roles in learning, memory, and numerous aspects of drug addiction. We therefore examined whether changes in these proteins are associated with incubation of craving for nicotine in rats. We found increased nicotine-seeking behaviour after 14 days of abstinence (compared to 1 day) along with elevated ERK and CREB activity in the Accumbens brain region suggesting that these proteins may be involved in the incubation phenomenon.

Tuatara (Sphenodon spp.) were once widespread over both the North and the South Islands of New Zealand approximately 1000 years ago but are now restricted to offshore islands due to introduced predators and habitat destruction. The survival of tuatara is now threatened by climate change because of isolation on islands that prevent them from migrating to cooler regions, and by their limited capacity to adapt due to their long life span and low genetic diversity. The thermal suitability of cooler regions for future translocations could be the key for tuatara conservation. The overall aim of the study was to determine the effect of cool temperature on the physiology, behaviour and egg incubation of Cook Strait tuatara (Sphenodon punctatus). As well answering specific questions about tuatara and their adaptation to cool temperature this study aimed at answering general questions about the behavioural and evolutionary ecology of reptiles. I first compared the preferred body temperature, feeding responses and tolerance to cold temperature of tuatara (Sphenodon punctatus) with three lizard species that inhabit the Otago region of southern New Zealand: Hoplodactylus maculatus, Naultinus gemmeus and Oligosoma maccanni. As well as testing the co-adaptation hypothesis between preferred body temperature and physiological performance of reptiles, I wanted to determine whether tuatara (which are planned to be reintroduced from a warmer site to the Otago region) have similar responses to cool temperature as do Otago lizard species. I found that tuatara show responses to cold temperatures similar to those of lizards from southern New Zealand, suggesting that if tuatara are translocated outside of their geographical range, they are likely to survive. I then tested if tuatara were capable of modifying their thermoregulatory behaviour if translocated to a cooler region. To do so, I conducted a laboratory experiment in which tuatara were provided with three thermal treatments corresponding to the thermal environments they would experience in their current habitat and the proposed reintroduction site. Contrary to the prediction of the cost-benefit model of thermoregulation, tuatara became active thermoregulators when the thermal quality of the habitat decreased. The results suggest that the model is less applicable to cold-adapted species and that if translocated to cooler regions, tuatara will be able to adjust their thermoregulatory behaviour to their thermal environment. Tuatara are temperature-dependent sex determination (TSD) reptiles and their translocation to cooler regions could have an dramatic impact on the sex ratio of new populations. To determine if potentially lower incubation temperature would be a limiting factor for the reintroduction of tuatara, I translocated eggs to the proposed reintroduction site. Some tuatara embryos developed at the site (and later hatched in the laboratory), but incubation lasted longer than in natural nests and all hatchlings were female. This trend observed in biased sex ratio might change in the context of climate change as an increase of soil temperature by 3�C would allow the production of males at the proposed site. The present study demonstrates that the translocation of tuatara further south, outside of their current geographical range, is possible and recommended. Tuatara show similar responses to cool temperatures compared with lizards that live in southern New Zealand, they can also adjust their thermoregulatory behaviour if translocated to cooler habitats, and tuatara embryos could potentially develop successfully in cooler regions. The greatest chance for the future survival of tuatara and TSD species in general, lies in translocation to other locations that are thermally suitable.

I studied aspects of the ecology of the Murray River turtle, Emydura macquarii, to determine the impact of the introduced red fox, Vulpes vulpes. The fox is one of Australia's worst vertebrate pests through its predation on livestock and native mammals, but their impact on reptilian communities is not known. I conducted a large-scale mark-recapture study to evaluate population growth of E. macquarii in the Albury region of the upper Murray River by determining growth, reproduction and survival. The study was conducted downstream of the first, and largest, impoundment on the Murray River, Lake Hume. Emydura macquarii predominantly inhabit the lagoons in the upper Murray River, as the mainstream and Lake are possibly too cool to maintain metabolic processes. They are easily captured in hoop traps and the use of live decoys maximises trap success. Over 2000 hatchling turtles were marked and released into two lagoons between January 1997 and January 1998. Growth of these individuals is rapid over the first few years but declines towards maturity, and is indeterminate after maturity. Although growth annuli are not well defined, even on young individuals, the von Bertalanffy model describes the growth of both male and female E. macquarii. Male turtles mature at 5-6 years and females mature at 10-12 years. Female turtles may maximise reproductive potential by delaying maturity and producing one relatively large clutch (mean = 21 eggs) per year, which is positively correlated with body size (PL). Although primarily related to body size, clutch size varies annually because of environmental conditions. If winter and summer rainfalls are below average and temperatures are above average, E. macquarii may reduce clutch size to increase the chance of the eggs surviving. Nesting predominantly occurs during the first major rain-bearing depression in November. Habitat variables, including distance from water, nearest nest, and tree, and soil type were measured for each nest to determine characteristics that attract predators. Nests close to the shoreline and trees are heavily preyed on, and nests constructed in sand are less likely to be destroyed by predators. Foxes detect nests through a combination of chemical cues from eggs and slight soil disturbances, whereas birds only destroy nests observed being constructed during the day. Female turtles alter nesting behaviour and construct nests much further away from water when foxes were removed and as a result, nests are less dense and away from trees. Thus in high predation risk areas, turtles minimise emergence and search times to reduce the risk of direct predation by foxes. Predation is reduced when nests are in lower densities and away from trees, because predators increase search efforts when nests are in higher densities and birds are more likely to destroy nests close to trees. Reproductive success is further reduced in high predation risk areas because more nests are constructed in sandy substrates where clutch success is reduced compared to incubation in more dense substrates. Where predators are a significant source of mortality, prey may use indirect methods, such as chemical recognition, to avoid encounters. Nesting turtles did not avoid areas where fox odour was present, suggesting that they assess predation pressure from foxes by other mechanisms, such as visual recognition. However, an innate response occurs to the odour of a once common predator on the Murray River, the eastern quoll (Dasyurus viverrinus), whereby turtles recognise and avoid nesting in areas where quoll odour is present. Therefore nesting turtles show a similar avoidance response to two different predators, using different mechanisms of detection. Similarly, predation risk may influence hatching times and nest emergence. The rate of embryonic development of E. macquarii may increase or eggs may hatch early so that the clutch hatches synchronously, thereby reducing the risk of predation through group emergence from the nest. Emydura macquarii reach densities of over 100 turtles.ha-1, with the majority of the population consisting of sexually mature individuals. Emydura macquarii has a Type III survival curve where mortality is extremely high in the egg stage (93% nest predation), remaining high over the hatchling stage (minimum survival rate- 10%), but decreasing rapidly throughout the juvenile stage (~70% juvenile survival). Adult survival is extremely high, with greater than 95% of adults surviving each year. Foxes through nest predation cause most mortality but a small proportion (~3%) of nesting adult females are killed by foxes each year. A removal program evaluated the impact of foxes. In 1996, fox numbers were monitored around four lagoons by spotlighting and non-toxic bait uptake. Foxes were removed from around two of the lagoons throughout 1997 and 1998, using spotlight shooting and 1080 bait poisoning. Fox numbers were continually monitored around all four lagoons during the study. Nest predation rates remained around 90% in all sites where foxes were present, but fell to less than 50% when foxes were removed. At the same time, predation on nesting female turtles was eliminated where foxes were removed. Demographic models using staged based survival schedules, together with growth and fecundity values for E. macquarii show a decline of 4% per year in these populations. Elasticity analyses shows that survival of adult female E. macquarii has the major influence on population stability and a reduction of nest predation alone is unlikely to address the population decline. Management options, such as reducing foxes prior to nesting around key lagoons, will stabilise the population decline, and eliminating foxes completely from certain areas with high dispersal potential, will promote recruitment of juvenile E. macquarii.