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

Political economics, collective action and wicked socio-ecological problems: A practice story from the field

Empowering integrative, sustainable and equitable approaches to wicked socio-ecological problems requires multiple disciplines and ways of knowing. Following calls for greater attention to political economics in this transdisciplinary work, we offer a practitioner perspective on political economy and collective action and their influences on our community engagement practice and public policy. Our perspective is grounded in a pervasive wicked problem in Australia, invasive rabbits, and the emergence of the Victorian Rabbit Action Network. The network grew out of a publically funded research project to support community-led action in rabbit management. Victorian residents and workers affected by rabbits – public and private land managers, scientists, government officers and others – were invited to engage in a participatory planning process to generate sustainable strategies to address the rabbit problem. Each stage in the process, which involved interviews, a workshop and consultations, was designed to nurture the critical enquiry, listening and learning skills of participants, advance understandings of the problem from multiple perspectives, generate collective options to guide decision-making, and encourage community-led collective action. We reflect on our understanding of these processes using the language and lens of political economics and, in particular, the context of democratic professionalism. In so doing, we define terms and refer to information resources that have enabled us to bring a practical working knowledge of political economics to our professional practice. Our intent is to motivate academics, community members, government officials, and scientists alike, to draw on their knowledge and field experiences and to share practice stories through the lens of political economics and collective action. This is an opportunity to engage each other in small ‘p’ politics of how we understand and act on wicked problems, to negotiate and connect across disciplines, practical experiences and human difference, so that people may work more creatively and effectively together to address the challenging issues of our time. &nbsp

Origins and population genetics of sambar deer (Cervus unicolor) introduced to Australia and New Zealand

Context. Some populations of introduced species cause significant undesirable impacts but can also act as reservoirs for genetic diversity. Sambar deer (Cervus unicolor) are ‘Vulnerable’ in their native range and invasive in Australia and New Zealand. Genetic data can be used to determine whether these introduced populations might serve as genetic reservoirs for declining native populations and to identify spatial units for management. Aims. We aimed to identify the provenance of sambar deer in Australia and New Zealand, and to characterise their genetic diversity and population structure. Methods. We used mitochondrial control region sequences and 18 nuclear microsatellite loci of 24 New Zealand and 63 Australian sambar deer collected across continuous habitat in each location. We estimated genetic diversity and population differentiation by using pairwise FST, AMOVA, and STRUCTURE analyses. We compared our data with 27 previously published native and invasive range sequences to identify phylogenetic relationships. Key results. Sambar deer in Australia and New Zealand are genetically more similar to those in the west of the native range (South and Central Highlands of India, and Sri Lanka), than to those in the east (eastern India, and throughout Southeast Asia). Nuclear genetic diversity was lower than in the native range; only one mitochondrial haplotype was found in each introduced population. Australian and New Zealand sambar deer were genetically distinct but there was no population structure within either population. Conclusions. The genetic differences we identified between these two introduced populations at putatively neutral loci indicate that there also may be underlying diversity at functional loci. The lack of population genetic structure that we found within introduced populations suggests that individuals within these popula- tions do not experience barriers to dispersal across the areas sampled. Implications. Although genetic diversity is reduced in the introduced range compared with the native range, sambar deer in Australia and New Zealand harbour unique genetic variants that could be used to strengthen genetic diversity in populations under threat in the native range. The apparent high levels of gene flow across the areas we sampled suggest that localised control is unlikely to be effective in Australia and New Zealand

Integrating Survey and Molecular Approaches to Better Understand Wildlife Disease Ecology

Infectious wildlife diseases have enormous global impacts, leading to human pandemics, global biodiversity declines and socio-economic hardship. Understanding how infection persists and is transmitted in wildlife is critical for managing diseases, but our understanding is limited. Our study aim was to better understand how infectious disease persists in wildlife populations by integrating genetics, ecology and epidemiology approaches. Specifically, we aimed to determine whether environmental or host factors were stronger drivers of Salmonella persistence or transmission within a remote and isolated wild pig (Sus scrofa) population. We determined the Salmonella infection status of wild pigs. Salmonella isolates were genotyped and a range of data was collected on putative risk factors for Salmonella transmission. We a priori identified several plausible biological hypotheses for Salmonella prevalence (cross sectional study design) versus transmission (molecular case series study design) and fit the data to these models. There were 543 wild pig Salmonella observations, sampled at 93 unique locations. Salmonella prevalence was 41% (95% confidence interval [CI]: 37-45%). The median Salmonella DICE coefficient (or Salmonella genetic similarity) was 52% (interquartile range [IQR]: 42-62%). Using the traditional cross sectional prevalence study design, the only supported model was based on the hypothesis that abundance of available ecological resources determines Salmonella prevalence in wild pigs. In the molecular study design, spatial proximity and herd membership as well as some individual risk factors (sex, condition score and relative density) determined transmission between pigs. Traditional cross sectional surveys and molecular epidemiological approaches are complementary and together can enhance understanding of disease ecology: abundance of ecological resources critical for wildlife influences Salmonella prevalence, whereas Salmonella transmission is driven by local spatial, social, density and individual factors, rather than resources. This enhanced understanding has implications for the control of diseases in wildlife populations. Attempts to manage wildlife disease using simplistic density approaches do not acknowledge the complexity of disease ecology

Challenges in confirming eradication success of invasive red-eared sliders

12 páginas, 4 figuras, 3 tablasConfirming eradication success can be notoriously difficult and costly, especially when the species is still present but remains undetected, due to very low population densities and imperfect detection methods. There has been a lack of research on appropriate guidelines and estimation procedures for declaring eradication success for programs aimed at eradicating alien reptiles. Here we develop quantitative rules for confirmation monitoring in eradication campaigns of the red-eared slider turtle (Trachemys scripta elegans). We used a database of slider trapping data from control and eradication campaigns conducted in localities across the Iberian Peninsula and southern France to construct models for inferring appropriate trapping efforts for confirming slider turtle eradication. Basking traps were slightly more efficient than net traps in capturing sliders, although trapping was an inefficient monitoring method given the low capture probabilities estimated. The results of our spatially-explicit eradication scenarios revealed the importance of habitat configuration in declaring eradication success. Declaration of eradication success is contingent on the thresholds set to minimise false positives (i.e., falsely declaring eradication successful), but in any scenario large trapping efforts were required to confirm eradication. Given the low estimated capture probabilities, alternative methods such as eDNA and visual surveys should be considered for monitoring sliders. We suggest that if the costs associated with the impact of alien sliders can be adequately estimated, then eradication can be confirmed by rules minimising both false positive and negative error rates. Otherwise., rules minimising false positive errors would be more appropriate.This research was conducted thanks to the Department of Economic Development, Jobs, Transport and Resources Invasive Plants and Animals Research Project When to stop: Defining rules for surveillance of red-eared slider turtles (Victoria State Government, Australia).Peer reviewe

Indian summer monsoon onset forecast skill in the UK Met Office initialized coupled seasonal forecasting system (GloSea5-GC2)

Accurate and precise forecasting of the Indian monsoon is important for the socio-economic security of India, with improvements in agriculture and associated sectors from prediction of the monsoon onset. In this study we establish the skill of the UK Met Office coupled initialized global seasonal forecasting system, GloSea5-GC2, in forecasting Indian monsoon onset. We build on previous work that has demonstrated the good skill of GloSea5 at forecasting interannual variations of the seasonal mean Indian monsoon using measures of large-scale circulation and local precipitation. We analyze the summer hindcasts from a set of three springtime start-dates in late April/early May for the 20-year hindcast period (1992-2011). The hindcast set features at least fifteen ensemble members for each year and is analyzed using five different objective monsoon indices. These indices are designed to examine large and local-scale measures of the monsoon circulation, hydrological changes, tropospheric temperature gradient, or rainfall for single value (area-averaged) or grid-point measures of the Indian monsoon onset. There is significant correlation between onset dates in the model and those found in reanalysis. Indices based on large-scale dynamic and thermodynamic indices are better at estimating monsoon onset in the model rather than local-scale dynamical and hydrological indices. This can be attributed to the model's better representation of large-scale dynamics compared to local-scale features. GloSea5 may not be able to predict the exact date of monsoon onset over India, but this study shows that the model has a good ability at predicting category-wise monsoon onset, using early, normal or late tercile categories. Using a grid-point local rainfall onset index, we note that the forecast skill is highest over parts of central India, the Gangetic plains, and parts of coastal India - all zones of extensive agriculture in India. El Niño Southern Oscillation (ENSO) forcing in the model improves the forecast skill of monsoon onset when using a large-scale circulation index, with late monsoon onset coinciding with El Niño conditions and early monsoon onset more common in La Niña years. The results of this study suggest that GloSea5's ensemble-mean forecast may be used for reliable Indian monsoon onset prediction a month in advance despite systematic model errors

The resolution sensitivity of the South Asian monsoon and Indo-Pacific in a global 0.35◦ AGCM

The South Asian monsoon is one of the most significant manifestations of the seasonal cycle. It directly impacts nearly one third of the world’s population and also has substantial global influence. Using 27-year integrations of a high-resolution atmospheric general circulation model (Met Office Unified Model), we study changes in South Asian monsoon precipitation and circulation when horizontal resolution is increased from approximately 200 to 40 km at the equator (N96 to N512, 1.9 to 0.35◦). The high resolution, integration length and ensemble size of the dataset make this the most extensive dataset used to evaluate the resolution sensitivity of the South Asian monsoon to date. We find a consistent pattern of JJAS precipitation and circulation changes as resolution increases, which include a slight increase in precipitation over peninsular India, changes in Indian and Indochinese orographic rain bands, increasing wind speeds in the Somali Jet, increasing precipitation over the Maritime Continent islands and decreasing precipitation over the northern Maritime Continent seas. To diagnose which resolution related processes cause these changes we compare them to published sensitivity experiments that change regional orography and coastlines. Our analysis indicates that improved resolution of the East African Highlands results in the improved representation of the Somali Jet and further suggests that improved resolution of orography over Indochina and the Maritime Continent results in more precipitation over the Maritime Continent islands at the expense of reduced precipitation further north. We also evaluate the resolution sensitivity of monsoon depressions and lows, which contribute more precipitation over northeast India at higher resolution. We conclude that while increasing resolution at these scales does not solve the many monsoon biases that exist in GCMs, it has a number of small, beneficial impacts

Current and emerging developments in subseasonal to decadal prediction

Weather and climate variations of subseasonal to decadal timescales can have enormous social, economic and environmental impacts, making skillful predictions on these timescales a valuable tool for decision makers. As such, there is a growing interest in the scientific, operational and applications communities in developing forecasts to improve our foreknowledge of extreme events. On subseasonal to seasonal (S2S) timescales, these include high-impact meteorological events such as tropical cyclones, extratropical storms, floods, droughts, and heat and cold waves. On seasonal to decadal (S2D) timescales, while the focus remains broadly similar (e.g., on precipitation, surface and upper ocean temperatures and their effects on the probabilities of high-impact meteorological events), understanding the roles of internal and externally-forced variability such as anthropogenic warming in forecasts also becomes important. The S2S and S2D communities share common scientific and technical challenges. These include forecast initialization and ensemble generation; initialization shock and drift; understanding the onset of model systematic errors; bias correct, calibration and forecast quality assessment; model resolution; atmosphere-ocean coupling; sources and expectations for predictability; and linking research, operational forecasting, and end user needs. In September 2018 a coordinated pair of international conferences, framed by the above challenges, was organized jointly by the World Climate Research Programme (WCRP) and the World Weather Research Prograame (WWRP). These conferences surveyed the state of S2S and S2D prediction, ongoing research, and future needs, providing an ideal basis for synthesizing current and emerging developments in these areas that promise to enhance future operational services. This article provides such a synthesis