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Animal Host-Microbe Interactions, Bethany J. Hoye, Andy Fenton

Faculty of Science, Medicine and Health - Papers: part A

The ecology of infectious diseases, as we currently recognise it, has been a major field of scientific research for over a century. Since the early work of John Snow, describing the epidemiology of cholera in 1850s London, and Ronald Ross, describing the transmission dynamics of malaria at the end of the 19th century, through the mathematical models of Kermack & McKendrick in the 1920s, and Anderson & May's revolutionary modelling of infectious disease dynamics in the late 1970s, the field of disease ecology has always sought to combine cutting‐edge analytical and theoretical tools with observational and experimental data to understand …

Effects Of Dredging On Critical Ecological Processes For Marine Invertebrates, Seagrasses And Macroalgae, And The Potential For Management With Environmental Windows Using Western Australia As A Case Study, Matthew Fraser, Jessie Short, Gary A. Kendrick, Dianne Mclean, John Keesing, Maria Byrne, M Julian Caley, Doug Clarke, Andrew R. Davis, Paul Erftemeijer, Stuart Field, Sam Gustin-Craig, John M. Huisman, Michael J. Keough, Paul Lavery, Ray Masini, Kathryn Mcmahon, Kerrie Mengersen, Michael Rasheed, John Statton, Jim Stoddart, Paul Wu

Faculty of Science, Medicine and Health - Papers: part A

Dredging can have significant impacts on benthic marine organisms through mechanisms such as sedimentation and reduction in light availability as a result of increased suspension of sediments. Phototrophic marine organisms and those with limited mobility are particularly at risk from the effects of dredging. The potential impacts of dredging on benthic species depend on biological processes including feeding mechanism, mobility, life history characteristics (LHCs), stage of development and environmental conditions. Environmental windows (EWs) are a management technique in which dredging activities are permitted during specific periods throughout the year; avoiding periods of increased vulnerability for particular organisms in specific locations. …

Linking Animal Contests And Community Structure Using Rockpool Fishes As A Model System, Kai Paijmans, Marian Y. L Wong

Faculty of Science, Medicine and Health - Papers: part A

Competition for limiting resources is a fundamental and well-established driver of niche partitioning, which in turn promotes species coexistence and biodiversity. Although contests are a well-known behavioural mechanism by which organisms compete over limiting resources, there has been surprisingly little application of contest theory to understanding interspecific interactions, niche partitioning, species coexistence and biodiversity. We investigated the link between contest dynamics and community structure using two intertidal rockpool fishes, Bathygobius cocosensis (Gobiidae) and Lepidoblennius haplodactylus (Tripterygiidae), as model species. We assessed the abundance and distribution of the two species on intertidal rocky shores of South-East Australia, and whether distribution patterns …

Three Arcs: Observations On The Archaeology Of The Elands Bay And Northern Cederberg Landscapes, Alex Mackay

Faculty of Science, Medicine and Health - Papers: part A

The area around Elands Bay and the adjacent interior landscapes west of the Doring River have been subject to intense archaeological investigation over the last ~50 years. The result is a region with great depth and diversity of archaeological information. In this paper I discuss three general observations that arise from the integration of data across this region. The first is that redundancy in site occupation is limited: even where many sites are excavated in a small area, understanding of the regional sequence cannot be assumed to be complete. The second is that humans did not live in rock shelters: …

Bayesian Methods For Comparing Species Physiological And Ecological Response Curves, Michael B. Ashcroft, Angelica Casanova-Katny, Kerrie Mengersen, Todd N. Rosenstiel, Johanna Turnbull, Jane Wasley, Melinda J. Waterman, Gustavo E. Zuniga, Sharon A. Robinson

Faculty of Science, Medicine and Health - Papers: part A

Many ecological questions require information on species' optimal conditions or critical limits along environmental gradients. These attributes can be compared to answer questions on niche partitioning, species coexistence and niche conservatism. However, these comparisons are unconvincing when existing methods do not quantify the uncertainty in the attributes or rely on assumptions about the shape of species' responses to the environmental gradient. The aim of this study was to develop a model to quantify the uncertainty in the attributes of species response curves and allow them to be tested for substantive differences without making assumptions about the shape of the responses. …

Dietary Carotenoids Change The Colour Of Southern Corroboree Frogs, Kate Umbers, Aimee J. Silla, Joseph A. Bailey, Allison K. Shaw, Phillip G. Byrne

Faculty of Science, Medicine and Health - Papers: part A

Animal coloration can be the result of many interconnected elements, including the production of colour-producing molecules de novo, as well as the acquisition of pigments from the diet. When acquired through the diet, carotenoids (a common class of pigments) can influence yellow, orange, and red coloration and enhanced levels of carotenoids can result in brighter coloration and/or changes in hue or saturation. We tested the hypothesis that dietary carotenoid supplementation changes the striking black and yellow coloration of the southern corroboree frog (Pseudophryne corroboree, Amphibia: Anura). Our dietary treatment showed no measurable difference in colour or brightness for black patches …

The Expanding Role Of Urban Fluvial Geomorphology: South Creek, Stephanie J. Kermode, Phillip Birtles, Geoff Vietz, Stephen Lynch, Jonathon Dixon, Carl Tippler, Michael Dean

Faculty of Science, Medicine and Health - Papers: part A

As aspirations for waterways in urban areas increases, and we demand more social and environmental values from them, an increased role exists for applied geomorphology in urban streams of the future. Previously, there has been a strong focus on flood mitigation and water quality in stream management, and even where geomorphology has been used to drive legislation (e.g. stream order, offsets), desired outcomes have not always been achieved. Understanding how physical attributes of channels are altered by urbanisation, and how the physical template and waterways can assist in achieving aspirational goals, is now central to urban landscape managers and planners. …

Two Lowland Tropical Spodosols From The Fiji Islands: First Report From Small Islands, David M. Leslie, Philomena Gangaiya, R John Morrison

Faculty of Science, Medicine and Health - Papers: part A

Spodosols, one of the major orders of soils in the U.S. Department of Agriculture Soil Taxonomy, are believed to be formed by down-profile movement of colloidal humic materials complexed with aluminum and iron. Conditions favoring formation of these soils are normally cool and humid climates, but some tropical Spodosols have been observed in continental and island situations, mainly at higher elevations. Here we report on observation of two Spodosols at low elevations in Fiji, the first such report for the South Pacific islands. Soil field descriptions and associated laboratory data are presented, along with interpretation of data in terms of …

Contrasting Topoclimate, Long-Term Macroclimatic Averages, And Habitat Variables For Modelling Ant Biodiversity At Landscape Scales, John R. Gollan, Daniel Ramp, Michael B. Ashcroft

Faculty of Science, Medicine and Health - Papers: part A

Spatial modelling is part of the solution for incorporating insects into conservation policy. Uptake, however, rests on identifying robust environmental predictors. Coarse-grained climate models based on long-term averages and similarly coarse environmental features may not be adequate, especially at regional scales where most planning is done. Here, we test whether topoclimatic variables, which are derived from local-scale climate forcing factors, are more important for structuring ant assemblages.

We quantified ant richness and species composition at 86 sites across a large (200 x 300 km) temperate region of southeast Australia, and tested the explanatory power of three groups of environmental variables: …

Woody Plant Encroachment Of Grasslands: A Comparison Of Terrestrial And Wetland Settings, Neil Saintilan, Kerrylee Rogers

Faculty of Science, Medicine and Health - Papers: part A

A global trend of woody plant encroachment of terrestrial grasslands is co-incident with woody plant encroachment of wetland in freshwater and saline intertidal settings. There are several arguments for considering tree encroachment of wetlands in the context of woody shrub encroachment of grassland biomes. In both cases, delimitation of woody shrubs at regional scales is set by temperature thresholds for poleward extent, and by aridity within temperature limits. Latitudinal expansion has been observed for terrestrial woody shrubs and mangroves, following recent warming, but most expansion and thickening has been due to the occupation of previously water-limited grassland/saltmarsh environments. Increases in …

Toxicity Of Fuel-Contaminated Soil To Antarctic Moss And Terrestrial Algae, Anna Nydahl, Catherine K. King, Jane Wasley, Dianne F. Jolley, Sharon A. Robinson

Faculty of Science, Medicine and Health - Papers: part A

Fuel pollution is a significant problem in Antarctica, especially in areas where human activities occur, such as at scientific research stations. Despite this, there is little information on the effects of petroleum hydrocarbons on Antarctic terrestrial biota. The authors demonstrate that the Antarctic mosses Bryum pseudotriquetrum, Schistidium antarctici, and Ceratodon purpureus, and the Antarctic terrestrial alga Prasiola crispa are relatively tolerant to Special Antarctic Blend (SAB) fuel-contaminated soil (measured as total petroleum hydrocarbons). Freshly spiked soils were more toxic to all species than were aged soils containing degraded fuel, as measured by photosynthetic efficiency (variable fluorescence/maximum fluorescence [Fv/Fm]), pigment content, …

Rules Of Attraction: Enticing Pelagic Fish To Mid-Water Remote Underwater Video Systems (Ruvs), Matthew Rees, Nathan A. Knott, G V. Fenech, Andrew R. Davis

Faculty of Science, Medicine and Health - Papers: part A

Mid-water baited remote underwater video systems (BRUVS) are becoming an increasingly popular tool for examining pelagic fish assemblages in a non-destructive, fisheries independent manner. As the technique is relatively novel, critical methodological questions such as the most appropriate attractant for pelagic fish to mid-water RUVS remain unresolved. In this study, we compared the relative effectiveness of 4 attractant treatments (sight: metallic reflectors, sound: bait fish recordings, scent: pilchards and their combination) on the time of first arrival, total abundance of pelagic fish and the relative abundance of 3 pelagic fish species: Trachurus novaezelandiae, Sarda australis and Seriola lalandi. Recordings were …

Limpet Shells As Unmodified Tools In Pleistocene Southeast Asia: An Experimental Approach To Assessing Fracture And Modification, Katherine A. Szabo, Brent Koppel

Faculty of Science, Medicine and Health - Papers: part A

Pleistocene tools manufactured in shell are rarely identified. This may in part be due to the complexity of shell as a raw material and associated challenges in recognising and interpreting shell modification. A series of unusually-shaped Scutellastra flexuosa limpets from c. 30,000 year old deposits in Golo Cave, eastern Indonesia were identified as putatively modified during midden analysis. A pilot programme of investigations into the microstructure and natural fracture patterns of this species, coupled with a series of use-wear experiments, demonstrates that some S. flexuosa shells were used as scrapers. The shells were used in unmodified form and were 'repurposed' …

Sex-Specific Triacylglycerides Are Widely Conserved In Drosophila And Mediate Mating Behavior, Jacqueline S.R Chin, Shane R. Ellis, Huong T. Pham, Stephen J. Blanksby, Kenji Mori, Qi Ling Koh, William J. Etges, Joanne Y. Yew

Faculty of Science, Medicine and Health - Papers: part A

Pheromones play an important role in the behavior, ecology, and evolution of many organisms. The structure of many insect pheromones typically consists of a hydrocarbon backbone, occasionally modified with various functional oxygen groups. Here we show that sex-specific triacylclyerides (TAGs) are broadly conserved across the subgenus Drosophila in 11 species and represent a novel class of pheromones that has been largely overlooked. In desert-adapted drosophilids, 13 different TAGs are secreted exclusively by males from the ejaculatory bulb, transferred to females during mating, and function synergistically to inhibit courtship from other males. Sex-specific TAGs are comprised of at least one short …

Testing The Ability Of Topoclimatic Grids Of Extreme Temperatures To Explain The Distribution Of The Endangered Brush-Tailed Rock-Wallaby (Petrogale Penicillata), Michael B. Ashcroft, Mike Cavanagh, Mark D. Eldridge, John R. Gollan

Faculty of Science, Medicine and Health - Papers: part A

Aim Many species are susceptible to climatic extremes, yet few fine-scale studies consider the factors that determine the distribution of extreme temperatures at landscape and regional scales. These factors include cold air drainage, canopy cover and topographical exposure to winds and radiation. We used the brush-tailed rock-wallaby (Petrogale penicillata) to test whether innovative topoclimatic grids of extreme temperatures are an important predictor of regional-scale species distributions. Location Hunter Valley region, New South Wales, Australia (31.2-33.4° S, 148.6-153.0° E). Methods We modelled the regional distributions of rock-wallaby observations and colonies using topoclimatic, macroclimatic, topographical and habitat factors. We employed a randomization …

A Simulation Study To Quantify Drift Fence Configuration And Spacing Effects When Sampling Mobile Animals, Murray Ellis, Michael Bedward

Faculty of Science, Medicine and Health - Papers: part A

Drift fences with traps are commonly used for ecological research and survey. Field studies have examined the effectiveness of selected fence layouts, but comprehensive field testing is impractical. We applied a simulation approach to investigate how the interaction of fence layout and animal movement type influence fence encounter rates. A range of fence layouts, varying in spacing and configuration, were chosen based on common field practices and recommendations in the literature. Animal movement patterns ranged from meandering (Brownian) to highly directional over distances of 10 to 500 m. We found that fences in short, straight, widely spaced arrangements would be …

Five Practical Uses Of Spatial Autocorrelation For Studies Of Coral Reef Ecology, S Hamylton

Faculty of Science, Medicine and Health - Papers: part A

The organisation of benthic communities across coral reefs is underpinned by spatially structured ecological processes and neighbourhood interactions such as larval dispersal, migration, competition and the spread of disease. These give rise to spatial autocorrelation in reef communities. This paper demonstrates how the measurement of spatial autocorrelation can profitably be incorporated into studies of coral reef ecology through a series of 5 simple statistical exercises: for the generation of maps depicting the strength of spatial relationships between ecological communities, as an indicator of optimal dimensions for sampling ecological communities on coral reefs, as a diagnostic tool for model misspecification, as …

The Sensitivity Of Topoclimatic Models To Fine-Scale Microclimatic Variability And The Relevance For Ecological Studies, Michael B. Ashcroft, John R. Gollan

Faculty of Science, Medicine and Health - Papers: part A

Microclimatic loggers are increasingly used to collect data from various habitats and interpolate ecologically meaningful landscape-scale topoclimatic grids. However, it is unknown how sensitive these grids are to finer-scale variations in microclimate. We performed a sensitivity analysis using three microclimatic loggers at 27 sites for 5 months in a semi-arid region of Western Australia. We partitioned the within- and between-site variance in temperature and produced 100 different topoclimatic models using a random sensor from each site. For the coldest temperatures, we found within-site variance was negligible (3 %), and models were strong (r 2 = 0.74) and the coefficients consistent. …

Estudios Ornitológicos Urbanos En Colombia: Revisión De Literatura, Carlos Delgado-Velez, Juana C. Correa-Hernandez

Faculty of Science, Medicine and Health - Papers: part A

This paper reviews what has been published in peer-reviewed journals about birds in Colombian cities, complementing an important Latin American review article that was recently published. This review identifies 55 papers dealing with 12 Colombian cities which exceeds by 50 the the number of studies previously considered. Species lists and Ecological Studies are the most frequent studies. Medellín is the city with the most studies (26 papers), whereas Bogotá (nine), Cali and Popayán (four each) had fewer publications. Although our review detects important publications not previously considered, we conclude that urban ornithology in Colombia is still in its infancy considering …

Demographic Patterns Of A Widespread Long-Lived Tree Are Associated With Rainfall And Disturbances Along Rainfall Gradients In Se Australia, Janet S. Cohn, Ian D. Lunt, Ross A. Bradstock, Quan Hua, Simon Mcdonald

Faculty of Science, Medicine and Health - Papers: part A

Predicting species distributions with changing climate has often relied on climatic variables, but increasingly there is recognition that disturbance regimes should also be included in distribution models. We examined how changes in rainfall and disturbances along climatic gradients determined demographic patterns in a widespread and long-lived tree species, Callitris glaucophylla in SE Australia. We examined recruitment since 1950 in relation to annual (200-600 mm) and seasonal (summer, uniform, winter) rainfall gradients, edaphic factors (topography), and disturbance regimes (vertebrate grazing [tenure and species], fire). A switch from recruitment success to failure occurred at 405 mm mean annual rainfall, coincident with a …

Fine-Grained Climate Data Alters The Interpretation Of A Trait-Based Cline, John R. Gollan, Michael B. Ashcroft, Daniel Ramp

Faculty of Science, Medicine and Health - Papers: part A

Investigating responses to climate often rely on macroclimatic models. This is problematic because of the potential to miss or wrongly attribute relationships. Here we compare the explanatory power of macroclimatic models and near-surface topoclimatic models. Body-size measurements of the ant species, Iridomyrmex purpureus, were collected from separate colonies spanning a range of climatic conditions in a large region (∼75,000 km2) of Australia. Regional regression was used to derive two topoclimatic variables, while ANUCLIM was used to derive macroclimatic variables. Relationships were tested using linear mixed-effect models with Akaike information criterion used as an indication of the relative goodness of fit …

The Importance Of Temporal Climate Variability For Spatial Patterns In Plant Diversity, Andrew D. Letten, Michael B. Ashcroft, David A. Keith, John R. Gollan, Daniel Ramp

Faculty of Science, Medicine and Health - Papers: part A

Spatial variation in absolute climatic conditions (means, maxima or minima) is widely acknowledged to play a fundamental role in controlling species diversity patterns. In contrast, while evidence is accumulating that variability around mean climatic conditions may also influence species coexistence and persistence, the importance of spatial variation in temporal climatic variability for species diversity is still largely unknown. We used a unique dataset capturing fine-scale spatial heterogeneity in temperature variability across 2490 plots in southeast Australia to examine the comparative strength of absolute temperature and temperature variability in explaining spatial variation in plant diversity. Across all plots combined and in …

Moisture, Thermal Inertia, And The Spatial Distributions Of Near-Surface Soil And Air Temperatures: Understanding Factors That Promote Microrefugia, Michael B. Ashcroft, John R. Gollan

Faculty of Science, Medicine and Health - Papers: part A

Climate change poses significant threats to biodiversity, but some species may be able to escape its effects in small locations with unusual and stable climates (microrefugia). However, there are still great uncertainties about where microrefugia are located, and the exact role that moisture plays in buffering extreme temperatures. In this study we quantified the effects of moisture on the distribution and variability of near-surface soil and air temperatures. We collected hourly 1 cm soil and 5 cm air temperatures and humidities at 111 sites from May 2011 to March 2012. Sites were diverse in terms of elevation (2-1428 m), distance …

High Muscle Mitochondrial Volume And Aerobic Capacity In A Small Marsupial (Sminthopsis Crassicaudata) Reveals Flexible Links Between Energy-Use Levels In Mammals, Terence Dawson, Koa Webster, Enhua Lee, William A. Buttemer

Faculty of Science, Medicine and Health - Papers: part A

We investigated the muscle structure–function relationships that underlie the aerobic capacity of an insectivorous, small (~15 g) marsupial, Sminthopsis crassicaudata (Family: Dasyuridae), to obtain further insight into energy use patterns in marsupials relative to those in placentals, their sister clade within the Theria (advanced mammals). Disparate hopping marsupials (Suborder Macropodiformes), a kangaroo (Macropus rufus) and a rat-kangaroo (Bettongia penicillata), show aerobic capabilities as high as those of ‘athletic’ placentals. Equivalent muscle mitochondrial volumes and cardiovascular features support these capabilities. We examined S. crassicaudata to determine whether highly developed aerobic capabilities occur elsewhere in marsupials, rather than being restricted to the …

Fine-Resolution (25 M) Topoclimatic Grids Of Near-Surface (5 Cm) Extreme Temperatures And Humidities Across Various Habitats In A Large (200 X 300 Km) And Diverse Region, Michael B. Ashcroft, John R. Gollan

Faculty of Science, Medicine and Health - Papers: part A

The development of fine-resolution climate grids is an important priority in explaining species' distributions at the regional scale and predicting how species may respond to variable and changing climates. Recent studies have demonstrated advantages of producing these grids using large networks of inexpensive climate loggers, as the resulting grids can capture local climatic variations over a range of environments. In this study we extend these methods to develop innovative fine-resolution (25 m) climate grids for a large region (∼200 x 300 km) of New South Wales, Australia. The key aspects of these grids is that they: (1) are based on …

Characterizing The Litter In Postfire Environments: Implications For Seedling Recruitment, Andrew J. Denham, Robert Whelan, Tony D. Auld

Faculty of Science, Medicine and Health - Papers: part A

Litter accumulation after fire influences the magnitude of seed predation and seed germination. How litter accumulation and patchiness influence postfire seedling recruitment is poorly known. Species with persistent seed banks have seeds available for germination in the immediate postfire period. In contrast, plants with transient seed banks must flower after fire to place seeds in the postfire habitat. In southeastern Australian sclerophyll forests, most seedling recruitment occurs within 3 yr after fire. We found that less litter had accumulated in sites mass, including some species with very light seeds. In contrast, the seed mass of transient seed bank species is …

Testing Common Habitat-Based Surrogates Of Invertebrate Diversity In A Semi-Arid Rangeland, John R. Gollan, Michael B. Ashcroft, Gerasimos Cassis, Andrew P. Donnelly, Scott A. Lassau

Faculty of Science, Medicine and Health - Papers: part A

Habitat-based surrogates are a low cost alternative to intensive biodiversity surveys, though they have been poorly investigated in semi-arid ecosystem compared to others such as temperate woodlands. In this study we tested potential habitat-based surrogates of invertebrate richness in a semi-arid rangeland in northwest Australia. Potential surrogates were: distance from artificial watering-point; soil hardness; habitat complexity; and individual complexity components. Generalised additive models (GAMs) were used to relate abundance and richness of selected invertebrates with environmental factors and cluster analysis was used to examine similarity in species composition. The most frequently selected factor was soil hardness, but taxa varied as …

Where Do Clonal Coral Larvae Go? Adult Genotypic Diversity Conflicts With Reproductive Effort In The Brooding Coral Pocillopora Damicornis, David J. Ayre, Karen Miller

Faculty of Science, Medicine and Health - Papers: part A

Earlier studies of the coral Pocillopora damicornis provide a conflicting picture of its use of sexual and asexual reproduction for population maintenance. In Western Australia, colonies are asexually viviparous, and populations appear to be maintained by localised asexual recruitment but founded by genotypically diverse colonists. However, on Australia¹s Great Barrier Reef (GBR), as in many other regions, populations display little or no evidence of any asexual recruitment. We used allozyme electrophoresis to test for asexual input into local populations of P. damicornis at One Tree Island on the southern GBR. Contrary to expectation we found that all of 136 planulae …

Towards A Sounder Fire Ecology, Edward A. Johnson, A Malcolm Gill, Ross Bradstock, Anders Granstrom, Louis Trabaud, Kiyoko Miyanishi

Faculty of Science, Medicine and Health - Papers: part A

This forum brings together fire ecologists from outside the current wildfire controversy in the US to give their views on three central topics related to ecosystems in which wildfires are an important process. First, how do fire behavior and ecological effects vary between ecosystems? Second, why does this variation require an understanding that goes beyond simple correlations between various fire and ecosystem variables to more careful causal models? Third, how can human values and goals be reconciled with fire disturbance processes in an ecologically sound manner?

East Salt Sparingly - Sprinkle, Don't Shake!, K E. Charlton, P L. Jooste

Faculty of Science, Medicine and Health - Papers: part A

The salt-blood pressure hypothesis states that an excessive salt intake leads to an increase in blood pressure in genetically susceptible persons and, if high intake is maintained long term, ultimately leads to sustained hypertension. It is estimated that about 3.3 million South Africans (12.6% and 16.3% of adult men and women, respectively) are hypertensive. However, not all subjects within a particular population respond equally to exposure to high-salt diets. Methods to identify those who are 'salt sensitive' remain in the research domain; therefore a population approach to the restriction of dietary salt intake is warranted. The message to 'eat salt …