Sex determination systems are exceptionally diverse and have undergone multiple and independent evolutionary transitions among species, particularly reptiles. However, the mechanisms underlying these transitions have not been established. Here we tested for differences in sex-linked markers in the only known reptile that is polymorphic for sex determination system, the spotted snow skink, Niveoscincus ocellatus, to quantify the genomic differences that have accompanied this transition. In a highland population, sex is determined genetically, whilst in a...

1) Phenotypic variation provides the framework for natural selection to work upon, enabling adaptive evolution. One of the most discernible manifestations of phenotypic variability is colour variation. When this variation is discrete, genetically-based colour pattern morphs occur simultaneously within a population. 2) Why and how colour polymorphisms are maintained is an evolutionary puzzle. Several evolutionary drivers have been hypothesized as influencing clinal patterns of morph frequency, with spatial variation in climate and predation being considered...

Genetic differentiation is characteristically weak in marine species making assessments of population connectivity and structure difficult. However the advent of genomic methods have increased genetic resolution, enabling studies to detect weak, but significant population differentiation within marine species. With an increasing number of studies employing high resolution genome-wide techniques, we are realising the connectivity of marine populations is often complex and quantifying this complexity can provide an understanding of the processes shaping marine species genetic...

Understanding how human activities influence immune response to environmental stressors can support biodiversity conservation across increasingly urbanizing landscapes. We studied a bobcat (Lynx rufus) population in urban southern California that experienced a rapid population decline from 2002–2005 due to notoedric mange. Because anticoagulant rodenticide (AR) exposure was an underlying complication in mange deaths, we aimed to understand sublethal contributions of urbanization and ARs on 65 biochemical markers of immune and organ function. Variance in immunological...

Accurate information on the growth rates of fish is crucial for fisheries stock assessment and management. Empirical life history parameters (von Bertalanffy growth) are widely fitted to cross-sectional size-at-age data sampled from fish populations. This method often assumes that environmental factors affecting growth remain constant over time. The current study utilized longitudinal life history information contained in otoliths from 412 juveniles and adults of gilthead seabream, Sparus aurata, a commercially important species fished and farmed...

1. Maintaining developmental heterogeneity of ecological communities within landscapes is crucial for sustainable native forest management. Consequently, methods to assess forest maturity (i.e. the degree to which the forest contains attributes and supports processes characteristic of late-successional forests) are valuable for making management decisions. However, no consistent, pragmatic method to quantify maturity that incorporates multiple ecosystem elements is available for many forest systems, including Australian wet eucalypt forests. 2. We draw upon forest community dynamics...

1. Under increasing anthropogenic nitrogen (N) deposition, some plant species will thrive while others will not. Previous work has shown that plant phylogeny can predict these responses, and that interactions with mycorrhizal fungi are a mechanism that drives variation in plant responses to N enrichment. Yet, much of this work has ignored the roles of other root-associated fungi and whole soil fungal communities in driving these responses. 2. We tested whether soil fungi mediate responses...

Fundamental to the definition of parental care is that care confers benefits to the offspring. However, the mechanisms resulting in these benefits remain poorly understood, particularly in species where postnatal care is not obligatory. Here, we address this shortcoming using a lizard, Liopholis whitii, in which family life is facultative and relatively simple – extending to prolonged associations between parents and offspring within the parental territory. Using a split-clutch design, we housed offspring either with...

Many pathogens infect multiple hosts, and spillover from domestic to wild species poses a significant risk for spread of diseases that threaten wildlife and humans. Documentation of cross-species transmission, and unravelling the mechanisms that drive it, remains a challenge. Focusing on co-occurring domestic and wild felids, we evaluate possible transmission mechanisms and evidence of spillover of ‘Candidatus Mycoplasma haemominutum’ (CMhm), an erythrocytic bacterial parasite of cats. We examine transmission and possibility of spillover by analysing...

Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania’s top carnivore, the Tasmanian devil (Sarcophilus harrisii), has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally-placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native...

The current extinction and climate change crises pressure us to predict population dynamics with ever-greater accuracy. Although predictions rest on the well-advanced theory of age-structured populations, two key issues remain poorly-explored. Specifically, how the age-dependency in demographic rates and the year-to-year interactions between survival and fecundity affect stochastic population growth rates. We use inference, simulations, and mathematical derivations to explore how environmental perturbations determine population growth rates for populations with different age-specific demographic rates and...

Anticoagulant rodenticides (ARs) are indiscriminate toxicants that threaten non-target predatory and scavenger species through secondary poisoning. Accumulating evidence suggests that AR exposure may have disruptive sublethal consequences on individuals that can affect fitness. We evaluated AR-related effects on genome wide expression patterns in a population of bobcats in southern California. We identify differential expression of genes involved in xenobiotic metabolism, endoplasmic reticulum stress response, epithelial integrity, and both adaptive and innate immune function. Further, we...

Knowing how many individuals are in a wildlife population allows informed management decisions to be made. Ecologists are increasingly using technologies, such as remotely piloted aircraft (RPA; commonly known as “drones,” unmanned aerial systems or unmanned aerial vehicles), for wildlife monitoring applications. Although RPA are widely touted as a cost-effective way to collect high-quality wildlife population data, the validity of these claims is unclear. Using life-sized, replica seabird colonies containing a known number of fake...

We give a non-technical introduction to convergence-divergence models, a new modeling approach for phylogenetic data that allows for the usual divergence of lineages after lineage-splitting but also allows for taxa to converge, i.e. become more similar over time. By examining the 3-taxon case in some detail we illustrate that phylogeneticists have been ``spoiled'' in the sense of not having to think about the structural parameters in their models by virtue of the strong assumption that...

Stressful conditions experienced during early development can have deleterious effects on offspring morphology, physiology and behaviour. However, few studies have examined how developmental stress influences an individual’s cognitive phenotype. Using a viviparous lizard, we show that the availability of food resources to a mother during gestation influences a key component of her offspring’s cognitive phenotype; their decision-making. Offspring from females who experienced low resource availability during gestation did better in an anti-predatory task that relied...

Standardized swim-up trials are used in IVF clinics to select particularly motile spermatozoa in order to increase the probability of a successful fertilization. Such trials demonstrate that sperm with longer telomeres have higher motility and lower levels of DNA damage. Regardless of whether sperm motility, and successful swim-up to fertilization sites, is a direct or correlational effect of telomere length or DNA damage, covariation between telomere length and sperm performance predicts a relationship between telomere...

Collecting data on unlicensed open‐access coastal activities, such as some types of recreational fishing, has often relied on telephone interviews selected from landline directories. However, this approach is becoming obsolete due to changes in communication technology such as a switch to unlisted mobile phones. Other methods, such as boat ramp interviews, are often impractical due to high labor cost. We trialed an autonomous, ultra‐high‐resolution photosampling method as a cost effect solution for direct measurements of...

Knowledge of the ecological dynamics between hosts and pathogens during the initial stages of disease emergence is crucial to understanding the potential for evolution of new interspecific interactions. Tasmanian devil (Sarcophilus harrisii) populations have declined precipitously owing to infection by a transmissible cancer (devil facial tumour disease, DFTD) that emerged approximately 20 years ago. Since the emergence of DFTD, and as the disease spreads across Tasmania, the number of devil has dropped up to 90%...

The mechanisms that determine patterns of species dispersal are important factors in the production and maintenance of biodiversity. Understanding these mechanisms helps to forecast the responses of species to environmental change. Here we used a comparative framework and genome-wide data obtained through RAD-seq to compare the patterns of connectivity among breeding colonies for five penguin species with shared ancestry, overlapping distributions, and differing ecological niches, allowing an examination of the intrinsic and extrinsic barriers governing...

Premise of the study: Nuclear microsatellite markers were developed for population genetic analysis of the threatened palaeoendemic conifer Pherosphaera hookeriana W. Archer (Podocarpaceae). Methods and Results: Fifteen variable loci were identified showing 1 to 13 alleles per population with seven loci displaying over four alleles in all populations and the average number of alleles per locus ranging from 4.8 to 5.93 per population. The observed heterozygosity per locus varied from 0.00 to 0.91 and overall...

1. New methods for species distribution models (SDMs) utilise presence‐absence (PA) data to correct the sampling bias of presence‐only (PO) data in a spatial point process setting. These have been shown to improve species estimates when both data sets are large and dense. However, is a PA data set that is smaller and patchier than hitherto examined able to do the same? Furthermore, when both data sets are relatively small, is there enough information contained...

Macroalgae underpin most temperate inshore ecosystems, but increasing macroalgal loss, fragmentation and range contractions are eroding connectivity among populations. Understanding loss, and predicting the likelihood of recovery, is dependent on knowledge of population connectivity and how it is mediated by variability in local seascapes. Although many studies of marine connectivity have focussed on influences of geographic distance on genetic structure, the contribution of intervening habitat is rarely considered. We tested the extent to which geographic...

Home-range estimation is an important application of animal tracking data that is frequently complicated by autocorrelation, sampling irregularity, and small effective sample sizes. We introduce a novel, optimal weighting method that accounts for temporal sampling bias in autocorrelated tracking data. This method corrects for irregular and missing data, such that oversampled times are downweighted and undersampled times are upweighted to minimize error in the home-range estimate. We also introduce computationally efficient algorithms that make this...

Sarcoptic mange, caused by the parasitic mite Sarcoptes scabiei, causes a substantive burden of disease to humans, domestic animals, and wildlife, globally. There are many effects of S. scabiei infection, culminating in the disease which hosts suffer. However, major knowledge gaps remain on the pathogenic impacts of this infection. Here, we focus on the bare-nosed wombat host (Vombatus ursinus) to investigate the effects of mange on: (i) host heat loss and thermoregulation, (ii) field metabolic...

Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behaviour of blue whales using dietary DNA metabarcoding of faecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87 % of prey DNA amplicons extracted from faecal samples from this population were sergestid shrimp, demonstrating that blue whales can...