Breeding biology, adult survival and territoriality of the white-browed treecreeper (climacteris affinis) in north-west Victoria, Australia

This is the first study to present empirical data describing the social organisation and breeding biology of the White-browed Treecreeper (Climacteris affinis). The species is typical of many small Australian passerines in that it has high annual survival (~80%), small clutches (mean = 1.95 ± 0.05), long breeding seasons (eggs laid August to November) and long incubation (17–18 days) and nestling periods (25–26 days), corrected for body weight. Reproductive effort is modified in response to variation in climatic conditions by adjusting the commencement of breeding and number of clutches laid per season, which is facilitated by an extended breeding season. White-browed Treecreepers occupied relatively large (mean = 8.4 ± 0.8 ha), all-purpose territories throughout the year. However, unlike many group territorial birds, territory size was not related to the number of occupants. The role of food limitation and climatic variability in relation to territory dispersion and life-history traits is explored. Facultative cooperative breeding was confirmed. Cooperative groups were formed through male philopatry, with usually only one, but up to three, male helpers present in a moderate fraction (35%) of breeding units. Thus, all species of Climacteris are now confirmed as facultative cooperatively breeding species, which provides further evidence for the aggregation of cooperative breeders at the generic level in mixed (i.e. cooperative and pair breeders) phylogenetic clades. In C. affinis, males may attain breeding positions through inheritance of their natal territory or by filling vacancies in nearby territories. Females obtained breeding positions by ‘floating’ as non-breeding residents in established territories, waiting for a vacancy to arise.

Dietary patterns throughout adult life are associated with body mass index, waist circumference, blood pressure, and red cell folate

Dietary patterns are important in the prevention of chronic disease; however, there are few studies that include repeat measures of dietary patterns. The objective of this study was to assess the relations between dietary patterns during adult life (at ages 36, 43, and 53 y) and risk factors for chronic disease at age 53 y. Participants of a longitudinal study of health completed a 5-d food diary at 3 occasions during adult life (n = 1265). Factor analysis was used to identify dietary patterns and a pattern score was calculated from the consumption of the food items in each dietary pattern. Means and 95% CI for dietary pattern scores were calculated for each risk factor category using random effects models adjusted for socio-demographic and health-related behaviors. In women, the fruit, vegetables, and dairy pattern was inversely associated with BMI (P < 0.004), waist circumference (P = 0.0007), blood pressure (P = 0.02), and was positively associated with red cell folate (P < 0.03). The ethnic foods and alcohol pattern was also inversely associated with blood pressure (P = 0.008), whereas the meat, potatoes and sweet foods pattern was positively associated with glycated hemoglobin (P = 0.01). In men, a mixed pattern was inversely associated with waist circumference (P = 0.02) and blood pressure (P = 0.01), whereas there were no significant associations with the ethnic foods and alcohol pattern. Specific dietary patterns throughout adult life were associated with chronic disease risk factors.

Heritability of corticosterone response and changes in life history traits during selection in the zebra finch

Vertebrates respond to environmental stressors through the neuro-endocrine stress response, which involves the production of glucocorticoids. We have selected independent, duplicate divergent lines of zebra finches for high, low and control corticosterone responses to a mild stressor. This experiment has shown that over the first four generations, the high lines have demonstrated a significant realized heritability of about 20%. However, the low lines have apparently not changed significantly from controls. This asymmetry in response is potentially because of the fact that all birds appear to be showing increased adaptation to the environment in which they are housed, with significant declines in corticosterone response in control lines as well as low lines. Despite the existence of two- to threefold difference in mean corticosterone titre between high and low lines, there were no observed differences in testosterone titre in adult male birds from the different groups. In addition, there were no consistent, significant differences between the lines in any of the life history variables measured – number of eggs laid per clutch, number of clutches or broods produced per pair, number of fledglings produced per breeding attempt, nor in any of egg, nestling and fledgling mortality. These results highlight the fact that the mechanisms that underlie variation in the avian physiological system can be modified to respond to differences between environments through selection. This adds an additional level of flexibility to the avian physiological system, which will allow it to respond to environmental circumstances.

Aspects of the biology of the abalone Haliotis laevigata and Haliotis scalaris

The abalone Haliotis laevigata Donovan is commercially exploited in southern Australia; Haliotis scalaris Leach is a smaller, noncommercial species. This thesis describes the early life history of both species and other aspects of the fishery biology of H. Iaevigata required for fishery management. Both abalone species recruit onto a crustose coralline substratum variously from spring to winter. After settlement the growth rate of both species Is linear for a number of years (1 .7mm/month for H. Iaevigata and 1.1mm/month for H. scalaris) . Crustose coralline algae are the main food during the first year of life but thereafter the diet switches largely to drift algae and seagrass. Survival of newly-settled cohorts differed between years and between species. Overall, it appeared to be density Independent at low densities but density-dependent at high densities, Recruitment strength (measured at 2-1/2 - 3 years of age) and natural mortality of adults in a closed population was measured over 17 years at West I. There were sequences of strong and weak recruitments, but no relationship with presumed spawning stock size was apparent. Adult natural mortality rates ranged from 0.02 to 0.86 and were strongly density dependent. Stingrays were a major, and octopuses a minor, cause of mortality. The fecundity of H. Iaevigata was investigated at a number of sites and was adequately described by linear regressions of fecundity on total weight. Fecundity ratios and growth rate differed between sites and fecundity appears subject to phenotyplc and genotypic variation. The short and long term movement of H. laevigata was also examined, !n short term studies sexually mature Individuals aggregate during the spawning season but disperse randomly at other times of the year. In the longer term the amount of movement depends on availability of crevice space and size. Movement is also directional and, at one site, was toward that of the approaching swell. A method is described for estimating density of abalone by using a free-range search technique and adjusting for individual variation in power and efficiency of different divers and in differing degrees of habitat heterogeneity. The method is useful for estimating recruitment strength and density of abalone in surveys of abalone stocks.

The fishery, biology and management of three inland water-bodies, Vietnam

This study was carried out from 1997 to 2004 and its findings have significantly enhanced our understanding on fishery, biology, and management of three inland water bodies in Vietnam. The study also provides insights into development of management guidelines and recommendations for future fisheries development in the research area.

Population biology of roach (Rutilis rutilus L.) in Lake Eildon, Australia

Roach (Rutilus rutilus), a previously unstudied cyprinid fish of European origin, were studied to ascertain the life history of the species in Australia. The population was found to display comparatively average growth, condition, and reproductive traits with that described elsewhere.

Biology and control of white blister rust of Brassicaceae vegetables

This research project was a response to the outbreak of white blister rust disease and its spread to Brassica oleracea crops in Australia. Disease management strategies based on the understanding of the Albugo - Brassica pathosystem, epidemiology, and the use of chemical control measures were developed for the Australian Brassica industry.

Biology and management of Murray cod reproduction within controlled environments

The emerging Murray cod aquaculture industry is currently restricted by a lack of consistent and year-round production of fingerlings. Biological information and reproductive technologies developed during this research have facilitated the development of indoor, environmentally-controlled breeding practices for this species, thereby enabling Murray cod juveniles to be produced on-demand.

Molecular biology of natriuretic peptides in reptiles and birds

The heart produces natriuretic peptides that are critical regulators of blood pressure and renal function. This study examined the molecular evolution of natriuretic peptides in vertebrates and discovered novel forms of the peptides in birds. The research outcomes advanced our knowledge of the importance of these peptides in animal physiology.

Identifying crucial gaps in our knowledge of the life-history of avian influenza viruses - An Australian perspective

We review our current knowledge of the epidemiology and ecology of avian influenza viruses (AIVs) in Australia in relation to the ecology of their hosts. Understanding the transmission and maintenance of low-pathogenic avian influenza (LPAI) viruses deserves scientific scrutiny because some of these may evolve to a high-pathogenic AIV (HPAI) phenotype. That the HPAI H5N1 has not been detected in Australia is thought to be a result of the low level of migratory connectivity between Asia and Australia. Some AIV strains are endemic to Australia, with Australian birds acting as a reservoir for these viruses. However, given the phylogenetic relationships between Australian and Eurasian strains, both avian migrants and resident birds within the continent must play a role in the ecology and epidemiology of AIVs in Australia. The extent to which individual variation in susceptibility to infection, previous infections, and behavioural changes in response to infection determine AIV epidemiology is little understood. Prevalence of AIVs among Australian avifauna is apparently low but, given their specific ecology and Australian conditions, prevalence may be higher in little-researched species and under specific environmental conditions.

Identification and genetic determination of an early life risk disposition for depressive disorder : atypical stress-related behaviour in early childhood

Progress in psychiatric genetics has been slow despite evidence of high heritability for most mental disorders. We argue that greater use of early detectable intermediate traits (endophenotypes) with the highest likely aetiological significance to depression, rather than complex clinical phenotypes, would be advantageous. Longitudinal data from the Western Australian Pregnancy Cohort (Raine) Study were used to identify an early life behavioural endophenotype for atypical hypothalamic-pituitaryadrenocortical function in adolescence, a neurobiological indicator of anxiety and depression. A set of descriptors representing rigid and reactive behaviour at age 1 year discriminated those in the top 20% of the free salivary cortisol exposure at age 17 years. Genetic association analysis revealed a male-sensitive effect to variation in three specific single nucleotide polymorphisms within selected genes underpinning the overall stress response. Furthermore, support for a polygenic effect on stress-related behaviour in childhood is presented.

Synthetic biology based metabolic engineering of saccharomyces cerevisiae for omega 6 and 3 PUFA production

Metabolic engineering of PUFA biosynthesis pathway using codon optimized DGA1 (Diacylglycerol acyltransferase), FAA3 (Acyl-CoA synthetase), desaturase genes named D9D, D12D, D5D, D6D, D17D and D6E elongase gene was studied in S. cerevisiae. Engineered yeast strains successfully demonstrated increase in lipid accumulation, and heterologous biosynthesis of linoleic, γ-linolenic, dihomo γ-linolenic, arachidonic and eicosapentaenoic acid.

Evolutionary biology of the invasive Northern Pacific seastar, Asterias amurensis

 Mark investigated the genetic basis of environmental adaptation in invasive and native A. amurensis larvae. He showed rapid changes in genetic architecture and gene expression underlie different physiological responses to elevated temperatures in invasive larvae. These findings are the first step in understanding the potential for range expansion within Australia.

Adding fuel to the "fire of life": energy budgets across levels of variation in ectotherms and endotherms

Energy metabolism - the "fire of life" - is the sum of the processes by which animals acquire energy, channel energy into useful functions, and dissipate energy from their bodies. Acquisition and allocation processes deal with energy mainly as a quantity, but energy is absorbed or expended over a period of time; therefore, the most relevant way to conceptualize energy budgets is with the use of rate functions. A large number of recent studies have examined co-variation in metabolic and behavioral traits among individuals. A general finding stemming from this body of work is that there is no single cause-and-effect mechanism driving these relationships, but that the direction of the effects is dynamic and shifts in different contexts and environments. However, the remarkable energetic differences between endotherms and ectotherms are an unexploited basis for achieving a further understanding of such relationships.