Causes of male sexual trait divergence in introduced populations of guppies

Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits. Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history.

Invader impact clarifies the roles of top-down and bottom-up effects on tropical snake populations

Disentangling the effects of prey limitation (bottom-up) and predation (top-down) processes on natural populations is difficult, but the perturbations introduced by an invasive species can provide pseudo-experimental evidence on this issue.

The short anger measure: development of a measure to assess anger in forensic populations

In this brief report, we describe the development of a brief measure of anger that may be used by nurses and other professionals to assess anger and changes in anger with male offenders. The Short Anger Measure, a 12-item self-report measure of angry feelings and aggressive impulses, was administered to 73 male offenders. The measure showed sound psychometric properties (internal consistency reliability, test–retest reliability) and concurrent validity with an established measure of anger. The potential use of the measure by nurses working in forensic settings is discussed.

Genetic connectivity between trans-oceanic populations of Capreolia implexa (Gelidiales, Rhodophyta) in cool temperate waters of Australasia and Chile.

Capreolia is a monospecific genus of gelidioid red algae and has been considered to be endemic to Australasia. This is the first report on the occurrence of Capreolia implexa outside of Australasian waters, based on investigations of fresh collections in southern Chile as well as Australia and New Zealand. Thalli are prostrate and form entangled turfs, growing on high intertidal rocks at three locations in Chile. Analyses of rbcL and cox1 revealed that C. implexa was of Australasian origin and also distinct from its relatives. Analyses of 1356. bp of cox1 revealed cryptic diversity, consisting of two genealogical groups within C. implexa; one present in Australia and New Zealand, and the other in Chile and Stewart Island, New Zealand. The extremely low genetic diversity found in C. implexa in Chile and the absence of shared haplotypes between Chile and Australasia suggest genetic bottleneck possibly as a result of colonization after dispersal by rafting from Stewart Island, New Zealand to Chile. © 2014 Elsevier B.V.

Is there evidence of selection in the dopamine receptor D4 gene in Australian invasive starling populations?

 Although population genetic theory is largely based on the premise that loci under study are selectively neutral, it has been acknowledged that the study of DNA sequence data under the influence of selection can be useful. In some circumstances, these loci show increased population differentiation and gene diversity. Highly polymorphic loci may be especially useful when studying populations having low levels of diversity overall, such as is often the case with threatened or newly established invasive populations. Using common starlings Sturnus vulgaris sampled from invasive Australian populations, we investigated sequence data of the dopamine receptor D4 gene (DRD4), a locus suspected to be under selection for novelty-seeking behaviour in a range of taxa including humans and passerine birds. We hypothesised that such behaviour may be advantageous when species encounter novel environments, such as during invasion. In addition to analyses to detect the presence of selection, we also estimated population differentiation and gene diversity using DRD4 data and compared these estimates to those from microsatellite and mitochondrial DNA sequence data, using the same individuals. We found little evidence for selection on DRD4 in starlings. However, we did find elevated levels of within-population gene diversity when compared to microsatellites and mitochondrial DNA sequence, as well as a greater degree of population differentiation. We suggest that sequence data from putatively nonneutral loci are a useful addition to studies of invasive populations, where low genetic variability is expected.

Ontogenic differences in sexual size dimorphism across four plover populations

Sexual size dimorphism (SSD) among adults is commonly observed in animals and is considered to be adaptive. However, the ontogenic emergence of SSD, i.e. the timing of divergence in body size between males and females, has only recently received attention. It is widely acknowledged that the ontogeny of SSD may differ between species, but it remains unclear how variable the ontogeny of SSD is within species. Kentish Plovers Charadrius alexandrinus and Snowy Plovers C. nivosus are closely related wader species that exhibit similar, moderate (c. 4%), male-biased adult SSD. To assess when SSD emerges we recorded tarsus length variation among 759 offspring in four populations of these species. Tarsus length of chicks was measured on the day of hatching and up to three times on recapture before fledging. In one population (Mexico, Snowy Plovers), males and females differed in size from the day of hatching, whereas growth rates differed between the sexes in two populations (Turkey and United Arab Emirates, both Kentish Plovers). In contrast, a fourth population (Cape Verde, Kentish Plovers) showed no significant SSD in juveniles. Our results suggest that adult SSD can emerge at different stages of development (prenatal, postnatal and post-juvenile) in different populations of the same species. We discuss the proximate mechanisms that may underlie these developmental differences.

Perceptions of crisis care in populations who self-referred to a telephone-based mental health triage service

Although psychiatric crises are very common in people with mental illness, little is known about consumer perceptions of mental health crisis care. Given the current emphasis on recovery-oriented approaches, shared decision-making, and partnering with consumers in planning and delivering care, this knowledge gap is significant. Since the late 1990s, access to Australian mental health services has been facilitated by 24/7 telephone-based mental health triage systems, which provide initial psychiatric assessment, referral, support, and advice. A significant proportion of consumers access telephone-based mental health triage services in a state of crisis, but to date, there has been no published studies that specifically report on consumer perceptions on the quality and effectiveness of the care provided by these services. This article reports on a study that investigated consumer perceptions of accessing telephone-based mental health triage services. Seventy-five mental health consumers participated in a telephone interview about their triage service use experience. An eight-item survey designed to measure the responsiveness of mental health services was used for data collection. The findings reported here focus on the qualitative data produced in the study. Consumer participants shared a range of perspectives on telephone-based mental health triage that provide invaluable insights into the needs, expectations, and service use experiences of consumers seeking assistance with a mental health problem. Consumer perceptions of crisis care have important implications for practice. Approaches and interventions identified as important to quality care can be used to inform educational and practice initiatives that promote person-centred, collaborative crisis care.

Addressing migration-related social and health inequalities in Australia: call for research funding priorities to recognise the needs of migrant populations

Objective Migrants constitute 26% of the total Australian population and, although disproportionately affected by chronic diseases, they are under-represented in health research. The aim of the present study was to describe trends in Australian Research Council (ARC)- and National Health and Medical Research Council (NHMRC)-funded initiatives from 2002 to 2011 with a key focus on migration-related research funding.Methods Data on all NHMRC- and ARC-funded initiatives between 2002 and 2011 were collected from the research funding statistics and national competitive grants program data systems, respectively. The research funding expenditures within these two schemes were categorised into two major groups: (1) people focused (migrant-related and mainstream-related); and (2) basic science focused. Descriptive statistics were used to summarise the data and report the trends in NHMRC and ARC funding over the 10-year period.Results Over 10 years, the ARC funded 15 354 initiatives worth A$5.5 billion, with 897 (5.8%) people-focused projects funded, worth A$254.4 million. Migrant-related research constituted 7.8% of all people-focused research. The NHMRC funded 12 399 initiatives worth A$5.6 billion, with 447 (3.6%) people-focused projects funded, worth A$207.2 million. Migrant-related research accounted for 6.2% of all people-focused initiatives.Conclusions Although migrant groups are disproportionately affected by social and health inequalities, the findings of the present study show that migrant-related research is inadequately funded compared with mainstream-related research. Unless equitable research funding is achieved, it will be impossible to build a strong evidence base for planning effective measures to reduce these inequalities among migrants.What is known about the topic? Immigration is on the rise in most developing countries, including Australia, and most migrants come from low- and middle-income countries. In Australia, migrants constitute 26% of the total Australian population and include refugee and asylum seeker population groups. Migrants are disproportionately affected by disease, yet they have been found to be under-represented in health research and public health interventions.What does this paper add? This paper highlights the disproportions in research funding for research among migrants. Despite migrants being disproportionately affected by disease burden, research into their health conditions and risk factors is grossly underfunded compared with the mainstream population.What are the implications for practitioners? Migrants represent a significant proportion of the Australian population and hence are capable of incurring high costs to the Australian health system. There are two major implications for practitioners. First, the migrant population is constantly growing, therefore integrating the needs of migrants into the development of health policy is important in ensuring equity across health service delivery and utilisation in Australia. Second, the health needs of migrants will only be uncovered when a clear picture of their true health status and other determinants of health, such as psychological, economic, social and cultural, are identified through empirical research studies. Unless equitable research funding is achieved, it will be impossible to build a strong evidence base for planning effective measures to reduce health and social inequalities among migrant communities.

Demographic status of Komodo dragons populations in Komodo National Park

The Komodo dragon (Varanus komodoensis) is the world's largest lizard and endemic to five islands in Eastern Indonesia. The current management of this species is limited by a paucity of demographic information needed to determine key threats to population persistence. Here we conducted a large scale trapping study to estimate demographic parameters including population growth rates, survival and abundance for four Komodo dragon island populations in Komodo National Park. A combined capture mark recapture framework was used to estimate demographic parameters from 925 marked individuals monitored between 2003 and 2012. Island specific estimates of population growth, survival and abundance, were estimated using open population capture-recapture analyses. Large island populations are characterised by near or stable population growth (i.e. λ~. 1), whilst one small island population (Gili Motang) appeared to be in decline (λ= 0.68 ± 0.09). Population differences were evident in apparent survival, with estimates being higher for populations on the two large islands compared to the two small islands. We extrapolated island specific population abundance estimates (considerate of species habitat use) to produce a total population abundance estimate of 2448 (95% CI: 2067-2922) Komodo dragons in Komodo National Park. Our results suggest that park managers must consider island specific population dynamics for managing and recovering current populations. Moreover understanding what demographic, environmental or genetic processes act independently, or in combination, to cause variation in current population dynamics is the next key step necessary to better conserve this iconic species.

Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations

Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.

Continental-scale decreases in shorebird populations in Australia

Decreases in shorebird populations are increasingly evident worldwide, especially in the East Asian–Australasian Flyway (EAAF). To arrest these declines, it is important to understand the scale of both the problem and the solutions. We analysed an expansive Australian citizen-science dataset, spanning the period 1973 to 2014, to explore factors related to differences in trends among shorebird populations in wetlands throughout Australia. Of seven resident Australian shorebird species, the four inland species exhibited continental decreases, whereas the three coastal species did not. Decreases in inland resident shorebirds were related to changes in availability of water at non-tidal wetlands, suggesting that degradation of wetlands in Australia’s interior is playing a role in these declines. For migratory shorebirds, the analyses revealed continental decreases in abundance in 12 of 19 species, and decreases in 17 of 19 in the southern half of Australia over the past 15 years. Many trends were strongly associated with continental gradients in latitude or longitude, suggesting some large-scale patterns in the decreases, with steeper declines often evident in southern Australia. After accounting for this effect, local variables did not explain variation in migratory shorebird trends between sites. Our results are consistent with other studies indicating that decreases in migratory shorebird populations in the EAAF are most likely being driven primarily by factors outside Australia. This reinforces the need for urgent overseas conservation actions. However, substantially heterogeneous trends within Australia, combined with declines of inland resident shorebirds indicate effective management of Australian shorebird habitat remains important.

Estimating animal populations and body sizes from burrows: marine ecologists have their heads buried in the sand

Most ecological studies require knowledge of animal abundance, but it can be challenging and destructive of habitat to obtain accurate density estimates for cryptic species, such as crustaceans that tunnel deeply into the seafloor, beaches, or mudflats. Such fossorial species are, however, widely used in environmental impact assessments, requiring sampling techniques that are reliable, efficient, and environmentally benign for these species and environments.2.Counting and measuring the entrances of burrows made by cryptic species is commonly employed to index population and body sizes of individuals. The fundamental premise is that burrow metrics consistently predict density and size. Here we review the evidence for this premise. We also review criteria for selecting among sampling methods: burrow counts, visual censuses, and physical collections.3.A simple 1:1 correspondence between the number of holes and population size cannot be assumed. Occupancy rates, indexed by the slope of regression models, vary widely between species and among sites for the same species. Thus, 'average' or 'typical' occupancy rates should not be extrapolated from site- or species specific field validations and then be used as conversion factors in other situations.4.Predictions of organism density made from burrow counts often have large uncertainty, being double to half of the predicted mean value. Whether such prediction uncertainty is 'acceptable' depends on investigators' judgements regarding the desired detectable effect sizes.5.Regression models predicting body size from burrow entrance dimensions are more precise, but parameter estimates of most models are specific to species and subject to site-to-site variation within species.6.These results emphasise the need to undertake thorough field validations of indirect census techniques that include tests of how sensitive predictive models are to changes in habitat conditions or human impacts. In addition, new technologies (e.g. drones, thermal-, acoustic- or chemical sensors) should be used to enhance visual census techniques of burrows and surface-active animals.