An impact evaluation of conservation investments targeting long-distance migratory species.

We evaluated the impact of a philanthropic program investing in the conservation of sites along the Pacific Americas Flyway, which spans >16,000 km of coastline and is used by millions of shorebirds. Using a quasi-experimental, mixed methods approach, we estimated what would have happened to shorebird populations at 17 wintering sites without the sustained and additional investment they received. We modeled shorebird populations across the entire flyway and at sites with and without investment. Combining shorebird abundance estimates with a land-cover classification model, we used the synthetic control method to create counterfactuals for shorebird trends at the treatment sites. We found no evidence of an overall effect across three outcome variables. Species- and site-level treatment effects were heterogeneous, with a few cases showing evidence of a positive effect, including a site with a high level of overall investment. Results suggest six shorebirds declined across the entire flyway, including at many Latin American sites. However, the percentage of flyway populations present at the sites remained stable, and the percentage at the treatment sites was higher (i.e., investment sites) than at control sites. Multiple mechanisms behind our results are possible, including that investments have yet to mitigate impacts and negative impacts at other sites are driving declines at the treatment sites. A limitation of our evaluation is the sole focus on shorebird abundance and the lack of data that prohibits the inclusion of other outcome variables. Monitoring infrastructure is now in place to design a more robust and a priori shorebird evaluation framework across the entire flyway. With this framework, it will prove easier to prioritize limited dollars to result in the most positive conservation outcomes.

Evaluación del impacto de la inversión para la conservación enfocada en especies migratorias de largo recorrido Resumen Evaluamos el impacto de un programa filantrópico que invierte en la conservación de sitios a lo largo de la Ruta Migratoria Pacífico-Américas, la cual abarca >16,000 km de la línea costera y millones de aves playeras la usan. Estimamos con una estrategia cuasiexperimental y de métodos mixtos lo que habría pasado con las poblaciones de estas aves en 17 sitios invernales sin la inversión adicional y continua que recibieron. Modelamos estas poblaciones en toda la ruta y en sitios con y sin inversión. Combinamos las estimaciones de aves playeras con el modelo de clasificación de la cobertura del suelo y usamos el método de control sintético para crear contrafactuales para las tendencias de las aves playeras en sitios de tratamiento. No encontramos evidencia alguna de un efecto generalizado en las tres variables de los resultados. Los efectos del tratamiento de especies y de sitio fueron heterogéneos, con unos cuantos casos que mostraron evidencia de un efecto positivo, incluido un sitio con un nivel elevado de inversión general. Los resultados sugieren que seis especies de aves playeras declinaron a lo largo de toda la ruta, incluyendo en varios sitios de América Latina. Sin embargo, el porcentaje de poblaciones de la ruta presentes en los sitios permaneció estable y el porcentaje en los sitios de tratamiento (sitios de inversión) fue más elevado que en los sitios control. Muchos mecanismos son posibles detrás de nuestros resultados, incluidas las inversiones que todavía no han mitigado impactos y los impactos negativos en otros sitios que están causando las declinaciones en los sitios de tratamiento. Una limitación en nuestra evaluación es el enfoque único en la abundancia de aves playeras y la falta de datos que impiden la inclusión de otras variables de los resultados. El monitoreo de la infraestructura ahora está en una posición en la que puede diseñar un marco de evaluación más robusto y a priori de las aves playeras a lo largo de toda la ruta. Con este marco, será más fácil priorizar los dólares limitados para que los resultados de conservación sean lo más positivos posible.

Consequences of seafood mislabeling for marine populations and fisheries management.

Over the past decade, seafood mislabeling has been increasingly documented, raising public concern over the identity, safety, and sustainability of seafood. Negative outcomes from seafood mislabeling are suspected to be substantial and pervasive as seafood is the world's most highly traded food commodity. Here we provide empirical systems-level evidence that enabling conditions exist for seafood mislabeling in the United States (US) to lead to negative impacts on marine populations and support consumption of products from poorly managed fisheries. Using trade, production, and mislabeling data, we determine that substituted products are more likely to be imported than the product listed on the label. We also estimate that about 60% of US mislabeled apparent consumption associated with the established pairs involves products that are exclusively wild caught. We use these wild-caught pairs to explore population and management consequences of mislabeling. We find that, compared to the product on the label, substituted products come from fisheries with less healthy stocks and greater impacts of fishing on other species. Additionally, substituted products are from fisheries with less effective management and with management policies less likely to mitigate impacts of fishing on habitats and ecosystems compared with the label product. While we provide systematic evidence of environmental impacts from food fraud, our results also highlight the current challenges with production, trade, and mislabeling data, which increase the uncertainty surrounding seafood mislabeling consequences. More integrated, holistic, and collaborative approaches are needed to understand mislabeling impacts and design interventions to minimize mislabeling.

Estimating illegal fishing from enforcement officers.

While illegal, unreported, and unregulated (IUU) fishing is a premier issue facing ocean sustainability, characterizing it is challenging due to its clandestine nature. Current approaches can be resource intensive and sometimes controversial. Using Chile as an example, we present a structured process leveraging existing capacity, fisheries officers, that provides a monitoring tool to produce transparent and stand-alone estimates on the level, structure, and characteristics of illegal fishing. We provide a national illegal fishing baseline for Chile, estimating illegal activity for 20 fisheries, representing ~ 70% of annual national landings. For four fisheries, we also estimate the relative importance of illegal activities across sectors, stakeholders, and infrastructure. While providing new information, our results also confirm previous evidence on the general patterns of illegality. Our approach provides an opportunity for government agencies to formalize their institutional knowledge, while accounting for potential biases and reducing fragmentation of knowledge that can prevent effective enforcement. Estimating illegal activity directly from fisheries enforcement officers is complementary to existing approaches, providing a cost-effective, rapid, and rigorous method to measure, monitor, and inform solutions to reduce IUU fishing.

The twenty most charismatic species.

Charisma is a term commonly used in conservation biology to describe species. However, as the term "charismatic species" has never been properly defined, it needs to be better characterized to fully meet its potential in conservation biology. To provide a more complete depiction, we collected information from four different sources to define the species currently considered to be the most charismatic and to understand what they represent to the Western public. First, we asked respondents of two separate surveys to identify the 10 animal species that they considered to be the most charismatic and associate them with one to six traits: Rare, Endangered, Beautiful, Cute, Impressive, and Dangerous. We then identified the wild animals featured on the website homepages of the zoos situated in the world's 100 largest cities as well as on the film posters of all Disney and Pixar films, assuming in both cases that the most charismatic species were generally chosen to attract viewers. By combining the four approaches, we set up a ranked list of the 20 most charismatic animals. The majority are large exotic, terrestrial mammals. These species were deemed charismatic, mainly because they were regarded as beautiful, impressive, or endangered, although no particular trait was discriminated, and species were heterogeneously associated with most of the traits. The main social characteristics of respondents did not have a significant effect on their choices. These results provide a concrete list of the most charismatic species and offer insights into the Western public's perception of charismatic species, both of which could be helpful to target new species for conservation campaigns.

Review: Allee effects in social species.

Allee effects have important implications for many aspects of basic and applied ecology. The benefits of aggregation of conspecific individuals are central to Allee effects, which have led to the widely held assumption that social species are more prone to Allee effects. Robust evidence for this assumption, however, remains rare. Furthermore, previous research on Allee effects has failed to adequately address the consequences of the different levels of organisation within social species' populations. Here, we review available evidence of Allee effects and model the role of demographic and behavioural factors that may combine to dampen or strengthen Allee effects in social species. We use examples across various species with contrasting social structure, including carnivores, bats, primates and eusocial insects. Building on this, we provide a conceptual framework that allows for the integration of different Allee effects in social species. Social species are characterised by nested levels of organisation. The benefits of cooperation, measured by mean individual fitness, can be observed at both the population and group levels, giving rise to "population level" and "group level" Allee effects respectively. We also speculate on the possibility of a third level, reporting per capita benefits for different individuals within a group (e.g. castes in social insects). We show that group size heterogeneity and intergroup interactions affect the strength of population-level demographic Allee effects. Populations with higher group size heterogeneity and in which individual social groups cooperate demonstrate the weakest Allee effects and may thus provide an explanation for why extinctions due to Allee effects are rare in social species. More adequately accounting for Allee effects in social species will improve our understanding of the ecological and evolutionary implications of cooperation in social species.

Increase in quantity and quality of suitable areas for invasive species as climate changes.

As climatically suitable range projections become increasingly used to assess distributions of species, we recommend systematic assessments of the quality of habitat in addition to the classical binary classification of habitat. We devised a method to assess occurrence probability, captured by a climatic suitability index, through which we could determine variations in the quality of potential habitat. This relative risk assessment circumvents the use of an arbitrary suitability threshold. We illustrated our method with 2 case studies on invasive ant species. We estimated invasion potential of the destroyer ant (Monomorium destructor) and the European fire ant (Myrmica rubra) on a global scale currently and by 2080 with climate change. We found that 21.1% of the world's landmass currently has a suitable climate for the destroyer ant and 16% has a suitable climate for European fire ant. Our climatic suitability index showed that both ant species would benefit from climate change, but in different ways. The size of the potential distribution increased by 35.8% for the destroyer ant. Meanwhile, the total area of potential distribution remained the same for the European fire ant (>0.05%), but the level of climatic suitability within this range increased greatly and led to an improvement in habitat quality (i.e., of invasive species' establishment likelihood). Either through quantity or quality of suitable areas, both invasive ant species are likely to increase the extent of their invasion in the future, following global climate change. Our results show that species may increase their range if either more areas become suitable or if the available areas present improved suitability. Studies in which an arbitrary suitability threshold was used may overlook changes in area quality within climatically suitable areas and as a result reach incorrect predictions. Incremento de la Cantidad y Calidad de Áreas Idóneas para Especies Invasoras a Medida que Cambia el Clima.

Ecological effects of environmental change.

This Special Issue of Ecology Letters presents contributions from an international meeting organised by Centre National de la Recherche Scientifique (CNRS) and Ecology Letters on the broad theme of ecological effects of global environmental change. The objectives of these articles are to synthesise, hypothesise and illustrate the ecological effects of environmental change drivers and their interactions, including habitat loss and fragmentation, pollution, invasive species and climate change. A range of disciplines is represented, including stoichiometry, cell biology, genetics, evolution and biodiversity conservation. The authors emphasise the need to account for several key ecological factors and different spatial and temporal scales in global change research. They also stress the importance of ecosystem complexity through approaches such as functional group and network analyses, and of mechanisms and predictive models with respect to environmental responses to global change across an ecological continuum: population, communities and ecosystems. Lastly, these articles provide important insights and recommendations for environmental conservation and management, as well as highlighting future research priorities.

Allee effects in ants.

1. Allee effects occur when the aggregation of individuals result in mutually beneficial intraspecific interactions whereby individual fitness, or per capita growth rate, increases with the number of individuals. Allee effects are common in social species due to their cooperative behaviours, such as breeding, feeding or defence. Allee effects have important implications for many aspects of basic and applied ecology. Over the past decades, the study of Allee effects has influenced population dynamics, community ecology, endangered species management and invasion biology. 2. Despite the fact that cooperation is the basis of their social structure, Allee effects have received little attention among eusocial insects. Extreme cooperation is common, and reproductive specialization of individuals occurs due to division of labour. These life-history traits suggest that the potential contribution of each caste to reproduction and survival may be differential and nonadditive. 3. We studied Allee effects in the invasive Argentine ant (Linepithema humile). In this species, many queens and workers are present in colonies, which allowed us to explore the differential effects of castes on the presence of Allee effects. In the laboratory, we measured brood production and individual survival in experimental colonies that differed in the initial numbers of queens and workers.4. Our results highlight the differential effect of queens and workers on survival and productivity. We found three positive density-dependent relationships indicative of component Allee effects at the colony level: both workers and queens had a positive effect on the productivity of the other caste, and queens had a positive effect on worker survivorship. 5. Our experimental results suggest a potential positive feedback between worker and queen abundance, which may have contributed to the evolution of large colony sizes. Our study provides the first evidence of Allee effects in eusocial insects and highlights the need to consider castes separately in population dynamics. Division of labour and differential reproductive rates are factors that should be integrated into the study of Allee effects.