Concurrent invasions of European starlings in Australia and North America reveal population-specific differentiation in shared genomic regions.

A species' success during the invasion of new areas hinges on an interplay between the demographic processes common to invasions and the specific ecological context of the novel environment. Evolutionary genetic studies of invasive species can investigate how genetic bottlenecks and ecological conditions shape genetic variation in invasions, and our study pairs two invasive populations that are hypothesized to be from the same source population to compare how each population evolved during and after introduction. Invasive European starlings (Sturnus vulgaris) established populations in both Australia and North America in the 19th century. Here, we compare whole-genome sequences among native and independently introduced European starling populations to determine how demographic processes interact with rapid evolution to generate similar genetic patterns in these recent and replicated invasions. Demographic models indicate that both invasive populations experienced genetic bottlenecks as expected based on invasion history, and we find that specific genomic regions have differentiated even on this short evolutionary timescale. Despite genetic bottlenecks, we suggest that genetic drift alone cannot explain differentiation in at least two of these regions. The demographic boom intrinsic to many invasions as well as potential inversions may have led to high population-specific differentiation, although the patterns of genetic variation are also consistent with the hypothesis that this infamous and highly mobile invader adapted to novel selection (e.g., extrinsic factors). We use targeted sampling of replicated invasions to identify and evaluate support for multiple, interacting evolutionary mechanisms that lead to differentiation during the invasion process.

Listen to Us: Perceptions of Animal Voice and Agency.

In many contexts, the interests of nonhuman animals (hereafter "animals") are often overlooked or considered to be a lower priority than those of humans. While strong arguments exist for taking animal moral claims seriously, these largely go unheard due to dominant anthropocentric attitudes and beliefs. This study aimed to explore how animal interests might be best represented in the human world. We conducted interviews to investigate people's perceptions of what it means to speak for other animals and who can reliably represent animal interests. Using Grounded Theory analytical methods, we identified one major theme: "Animal voice", and its subthemes: "Animals do/do not have a voice", "Human language constructs realities and paradigms", and "Let animals speak". Our findings illustrate how human language constructs contribute to shaping the realities of animals by contextually defining them as voiceless. This has serious implications for animals, society, and the environment. Drawing parallels with the relevant literature, our results reflect calls for the social and political recognition of animal voice as fundamental to animal representation. We recommend future research to focus on developing ethical and compassionate approaches to understanding animal subjective experiences to empower and amplify animal voices.

Genetics and Plasticity Are Responsible for Ecogeographical Patterns in a Recent Invasion.

Patterns of covariation between phenotype and environment are presumed to be reflective of local adaptation, and therefore translate to a meaningful influence on an individual's overall fitness within that specific environment. However, these environmentally driven patterns may be the result of numerous and interacting processes, such as genetic variation, epigenetic variation, or plastic non-heritable variation. Understanding the relative importance of different environmental variables on underlying genetic patterns and resulting phenotypes is fundamental to understanding adaptation. Invasive systems are excellent models for such investigations, given their propensity for rapid evolution. This study uses reduced representation sequencing data paired with phenotypic data to examine whether important phenotypic traits in invasive starlings (Sturnus vulgaris) within Australia appear to be highly heritable (presumably genetic) or appear to vary with environmental gradients despite underlying genetics (presumably non-heritable plasticity). We also sought to determine which environmental variables, if any, play the strongest role shaping genetic and phenotypic patterns. We determined that environmental variables-particularly elevation-play an important role in shaping allelic trends in Australian starlings and may also reinforce neutral genetic patterns resulting from historic introduction regime. We examined a range of phenotypic traits that appear to be heritable (body mass and spleen mass) or negligibly heritable (e.g. beak surface area and wing length) across the starlings' Australian range. Using SNP variants associated with each of these phenotypes, we identify key environmental variables that correlate with genetic patterns, specifically that temperature and precipitation putatively play important roles shaping phenotype in this species. Finally, we determine that overall phenotypic variation is correlated with underlying genetic variation, and that these interact positively with the level of vegetation variation within a region, suggesting that ground cover plays an important role in shaping selection and plasticity of phenotypic traits within the starlings of Australia.

A critical review of the compassionate conservation debate.

Compassionate conservation holds that compassion should transform conservation. It has prompted heated debate and has been criticized strongly. We reviewed the debate to characterize compassionate conservation and to philosophically analyze critiques that are recurring and that warrant further critical attention. The necessary elements of compassionate conservation relate to the moral value of sentient animals and conservation and to science and conservation practice. Although compassionate conservation has several nontraditional necessary conditions, it also importantly allows a degree of pluralism in values and scientific judgment regarding animals and conservation practice. We identified 52 specific criticisms from 11 articles that directly critique compassionate conservation. We closely examined 33 of these because they recurred regularly or included substantial questions that required further response. Critics criticized compassionate conservation's ethical foundations, scientific credentials, clarity of application, understanding of compassion, its alleged threat to conservation and biodiversity. Some criticisms, we found, are question begging, confused, or overlook conceptual complexity. These criticisms raise questions for critics and proponents, regarding, for example, equal versus differential intrinsic moral value of different sentient animals (including humans), problems of natural and human-caused suffering of wild animals and predation, and the acceptability of specific conservation practices within compassionate conservation. By addressing recurring and faulty critiques of compassionate conservation and identifying issues for compassionate conservation to address, this review provides a clearer basis for crucial ongoing interdisciplinary dialogue about ethics, values, and conservation.

Una Revisión Crítica del Debate sobre la Conservación Compasiva Resumen La conservación compasiva sostiene que la compasión debería transformar la conservación. Esta idea ha impulsado un debate acalorado y ha sido criticada fuertemente. Revisamos el debate para caracterizar la conservación compasiva y para analizar filosóficamente las críticas recurrentes y que ameritan una mayor atención crítica. Los elementos necesarios de la conservación compasiva están relacionados con el valor moral de los animales sensibles y de la conservación y con la ciencia y la práctica de la conservación. Aunque la conservación compasiva tiene varias condiciones no tradicionales necesarias, también permite de manera muy importante un cierto grado de pluralismo en los valores y el juicio científico con respecto a los animales y a la práctica de la conservación. Identificamos 52 críticas específicas en once artículos que criticaban directamente a la conservación compasiva. Analizamos minuciosamente 33 de estas críticas porque aparecieron regularmente o porque incluían preguntas sustanciales que requerían de una respuesta más profunda. Las críticas se centraban en las razones éticas de la conservación compasiva, sus credenciales científicas, la claridad de su aplicación, el entendimiento del concepto compasión y su presunta amenaza para la conservación y la biodiversidad. Notamos que algunas críticas dejan preguntas pendientes, son confusas o ignoran la complejidad conceptual. Estas críticas generan preguntas para los críticos y para los partidarios de la conservación compasiva con respecto al valor moral intrínseco igual o diferencial de distintos animales sensibles (incluyendo a los humanos), problemas relacionados con el sufrimiento natural y causado por humanos y con la depredación que sufren los animales silvestres y la aceptabilidad de prácticas específicas de conservación dentro de la conservación compasiva. Con la identificación de las críticas recurrentes y fallidas que se le hacen a la conservación compasiva y los temas que ésta debe abordar, esta revisión proporciona una base más clara para el importante diálogo interdisciplinario que existe sobre la ética, los valores y la conservación.

Signatures of selection in a recent invasion reveal adaptive divergence in a highly vagile invasive species.

A detailed understanding of population genetics in invasive populations helps us to identify drivers of successful alien introductions. Here, we investigate putative signals of selection in Australian populations of invasive common starlings, Sturnus vulgaris, and seek to understand how these have been influenced by introduction history. We used reduced representation sequencing to determine population structure, and identify Single Nucleotide Polymorphisms (SNPs) that are putatively under selection. We found that since their introduction into Australia, starling populations have become genetically differentiated despite the potential for high levels of dispersal, and that starlings have responded to selective pressures imposed by a wide range of environmental conditions across their geographic range. Isolation by distance appears to have played a strong role in determining genetic substructure across the starling's Australian range. Analyses of candidate SNPs that are putatively under selection indicated that aridity, precipitation and temperature may be important factors driving adaptive variation across the starling's invasive range in Australia. However, we also noted that the historic introduction regime may leave footprints on sites flagged as being under adaptive selection, and encourage critical interpretation of selection analyses in non-native populations.

Senescence of song revealed by a long-term study of the Seychelles warbler (Acrocephalus sechellensis).

Senescence is widespread in nature, often resulting in diminishing survival or reproduction with age, but its role in age-dependent variation in sexual traits is often poorly understood. One reason is that few studies of sexual traits consider non-linear relationships with age, or only consider a narrow range of years relative to the life span of the species. Birdsong has evolved to allow assessment of conspecific quality in numerous bird species. Whilst theory and empirical work suggests that song may become more elaborate with age, there are a paucity of long-term studies testing whether song is associated with age or longevity. In particular, the occurrence of song senescence has rarely been demonstrated. Using an exceptional long-term dataset for the Seychelles warbler (Acrocephalus sechellensis), we analysed relationships between male song, age, survival, and longevity. This species is a long-lived songbird with early life increases, followed by senescent declines, in survival and reproduction. The study population (Cousin Island, Seychelles) is a closed population, with no depredation of adults, providing an excellent opportunity to study senescence in free-living animals. We tested whether song traits were related to age at recording, future survival, longevity, and territory quality. We found age-dependent changes in five song traits (duration, maximum frequency, peak frequency of songs, and duration and frequency bandwidth of trills). Relationships with age were quadratic, indicating reversal in the expression of song coinciding with the onset of senescence in reproduction and survival in this species. One song trait (trill bandwidth) had a quadratic relationship with future survival, but no song traits were related to longevity, suggesting age-related patterns were not the result of selective disappearance. Our study provides one of the first examples of functional senescence in song, offering new insights into avian senescence. Late-life declines in avian song, and possibly other sexual traits, may be more common than currently known, and may play a fundamental role in age-dependent changes in reproductive success.

Environmental Influences on Neuromorphology in the Non-Native Starling Sturnus vulgaris.

Cognitive traits are predicted to be under intense selection in animals moving into new environments and may determine the success, or otherwise, of dispersal and invasions. In particular, spatial information related to resource distribution is an important determinant of neural development. Spatial information is predicted to vary for invasive species encountering novel environments. However, few studies have tested how cognition or neural development varies intraspecifically within an invasive species. In Australia, the non-native common starling Sturnus vulgaris inhabits a range of habitats that vary in seasonal resource availability and distribution. We aimed to identify variations in the brain mass and hippocampus volume of starlings in Australia related to environmental variation across two substantially different habitat types. Specifically, we predicted variation in brain mass and hippocampal volume in relation to environmental conditions, latitude, and climatic variables. To test this, brain mass and volumes of the hippocampus and two control brain regions (telencephalon and tractus septomesencephalicus) were quantified from starling brains gathered from across the species' range in south eastern Australia. When comparing across an environmental gradient, there was a significant interaction between sex and environment for overall brain mass, with greater sexual dimorphism in brain mass in inland populations compared to those at the coast. There was no significant difference in hippocampal volume in relation to environmental measures (hippocampus volume, n = 17) for either sex. While these data provide no evidence for intraspecific environmental drivers for changes in hippocampus volume in European starlings in Australia, they do suggest that environmental factors contribute to sex differences in brain mass. This study identifies associations between the brain volume of a non-native species and the environment; further work in this area is required to elucidate the mechanisms driving this relationship.

Simulated Disperser Analysis: determining the number of loci required to genetically identify dispersers.

Empirical genetic datasets used for estimating contemporary dispersal in wild populations and to correctly identify dispersers are rarely tested to determine if they are capable of providing accurate results. Here we test whether a genetic dataset provides sufficient information to accurately identify first-generation dispersers. Using microsatellite data from three wild populations of common starlings (Sturnus vulgaris), we artificially simulated dispersal of a subset of individuals; we term this 'Simulated Disperser Analysis'. We then ran analyses for diminishing numbers of loci, to assess at which point simulated dispersers could no longer be correctly identified. Not surprisingly, the correct identification of dispersers varied significantly depending on the individual chosen to 'disperse', the number of loci used, whether loci had high or low Polymorphic Information Content and the location to which the dispersers were moved. A review of the literature revealed that studies that have implemented first-generation migrant detection to date have used on average 10 microsatellite loci. Our results suggest at least 27 loci are required to accurately identify dispersers in the study system evaluated here. We suggest that future studies use the approach we describe to determine the appropriate number of markers needed to accurately identify dispersers in their study system; the unique nature of natural systems means that the number of markers required for each study system will vary. Future studies can use Simulated Disperser Analysis on pilot data to test marker panels for robustness to contemporary dispersal identification, providing a powerful tool in the efficient and accurate design of studies using genetic data to estimate dispersal.

Three Molecular Markers Show No Evidence of Population Genetic Structure in the Gouldian Finch (Erythrura gouldiae).

Assessment of genetic diversity and connectivity between regions can inform conservation managers about risk of inbreeding, potential for adaptation and where population boundaries lie. The Gouldian finch (Erythrura gouldiae) is a threatened species in northern Australia, occupying the savannah woodlands of the biogeographically complex monsoon tropics. We present the most comprehensive population genetic analysis of diversity and structure the Gouldian finch using 16 microsatellite markers, mitochondrial control region and 3,389 SNPs from genotyping-by-sequencing. Mitochondrial diversity is compared across three related, co-distributed finches with different conservation threat-statuses. There was no evidence of genetic differentiation across the western part of the range in any of the molecular markers, and haplotype diversity but not richness was lower than a common co-distributed species. Individuals within the panmictic population in the west may be highly dispersive within this wide area, and we urge caution when interpreting anecdotal observations of changes to the distribution and/or flock sizes of Gouldian finch populations as evidence of overall changes to the population size of this species.

Human residential status and habitat quality affect the likelihood but not the success of lapwing breeding in an urban matrix.

Wildlife living in the suburbs faces the challenge of dealing with human presence and yard management (including the occurrence of pets) which vary at the scale of the house block. This study examined the influence of ecological factors (e.g. extent of grass and food availability) and anthropogenic factors (e.g. human activity and garden usage) on breeding site choice and reproductive success of the ground-nesting masked lapwing Vanellus miles on Phillip Island, Australia. Lapwings nested less frequently in residential properties (high levels of human usage) compared with vacant blocks and holiday houses. They were also more likely to breed on properties with high food availability and larger areas of grass. None of these variables influenced clutch size or the probability of eggs hatching, although larger clutches and higher hatching rates tended to be associated with more food. This study shows that, for an urban exploiting species, habitat quality is not homogenous at the scale of the house block, and that human activity is avoided by a species generally considered highly tolerant of people.

Tests of ecogeographical relationships in a non-native species: what rules avian morphology?

The capacity of non-native species to undergo rapid adaptive change provides opportunities to research contemporary evolution through natural experiments. This capacity is particularly true when considering ecogeographical rules, to which non-native species have been shown to conform within relatively short periods of time. Ecogeographical rules explain predictable spatial patterns of morphology, physiology, life history and behaviour. We tested whether Australian populations of non-native starling, Sturnus vulgaris, introduced to the country approximately 150 years ago, exhibited predicted environmental clines in body size, appendage size and heart size (Bergmann's, Allen's and Hesse's rules, respectively). Adult starlings (n = 411) were collected from 28 localities from across eastern Australia from 2011 to 2012. Linear models were constructed to examine the relationships between morphology and local environment. Patterns of variation in body mass and bill surface area were consistent with Bergmann's and Allen's rules, respectively (small body size and larger bill size in warmer climates), with maximum summer temperature being a strongly weighted predictor of both variables. In the only intraspecific test of Hesse's rule in birds to date, we found no evidence to support the idea that relative heart size will be larger in individuals which live in colder climates. Our study does provide evidence that maximum temperature is a strong driver of morphological adaptation for starlings in Australia. The changes in morphology presented here demonstrate the potential for avian species to make rapid adaptive changes in relation to a changing climate to ameliorate the effects of heat stress.

Swooping in the Suburbs; Parental Defence of an Abundant Aggressive Urban Bird against Humans.

Masked Lapwings, Vanellus miles, often come into 'conflict' with humans, because they often breed in close proximity to humans and actively defend their ground nests through aggressive behaviour, which typically involves swooping. This study examined whether defensive responses differed when nesting birds were confronted with different human stimuli ('pedestrian alone' vs. 'person pushing a lawn mower' approaches to nests) and tested the effectiveness of a commonly used deterrent (mock eyes positioned on the top or back of a person's head) on the defensive response. Masked Lapwings did not swoop closer to a person with a lawn mower compared with a pedestrian, but flushed closer and remained closer to the nest in the presence of a lawn mower. The presence of eye stickers decreased (pedestrians) and increased (lawn mowers) swooping behaviour. Masked Lapwings can discriminate between different human activities and adjust their defensive behaviour accordingly. We also conclude that the use of eye stickers is an effective method to mitigate the human-lapwing 'conflict' in some, but not all, circumstances.