Value of combining transect counts and telemetry data to determine short-term population trends in a globally threatened species.

To evaluate conservation interventions, it is necessary to obtain reliable population trends for short (<10 years) time scales. Telemetry can be used to estimate short-term survival rates and is a common tool for assessing population trends, but it has limitations and can be biased toward specific behavioral traits of tagged individuals. Encounter rates calculated from transects can be useful for assessing changes across multiple species, but they can have large confidence intervals and be affected by variations in survey conditions. The decline of African vultures has been well-documented, but understanding of recent trends is lacking. To examine population trends, we used survival estimates from telemetry data collected over 6 years (primarily for white-backed vultures [Gyps africanus]) and transect counts conducted over 8 years (for 7 scavenging raptors) in 3 large protected areas in Tanzania. Population trends were estimated using survival analysis combined with the Leslie Lefkovitch matrix model from the telemetry data and using Bayesian mixed effects generalized linear regression models from the transect data. Both methods showed significant declines for white-backed vultures in Ruaha and Nyerere National Parks. Only telemetry estimates suggested significant declines in Katavi National Park. Encounter rates calculated from transects also showed declines in Nyerere National Park for lappet-faced vultures (38% annual declines) and Bateleurs (18%) and in Ruaha National Park for white-headed vultures (Trigonoceps occipitalis) (19%). Mortality rates recorded and inferred from telemetry suggested that poisoning is prevalent. However, only 6 mortalities of the 26 presumed mortalities were confirmed to be caused by poisoning, highlighting the challenges of determining the cause of death when working across large landscapes. Despite declines, our data provide evidence that southern Tanzania has higher current encounter rates of African vultures than elsewhere in East Africa. Preventing further declines will depend greatly on mitigating poisoning. Based on our results, we suggest that the use of multiple techniques improves understanding of population trends over the short term.

Importancia de combinar los conteos de transectos y los datos de telemetría para determinar las tendencias poblacionales a corto plazo de especies amenazadas a nivel mundial Resumen Para evaluar las intervenciones de conservación es necesario obtener tendencias poblacionales confiables para escalas temporales cortas (<10 años). La telemetría puede usarse para estimar las tasas de supervivencia a corto plazo, además de que es una herramienta común para analizar las tendencias poblacionales, pero tiene limitantes y puede sesgarse con el comportamiento específico de los individuos marcados. Las tasas de encuentro calculadas a partir de transectos pueden ser útiles para analizar cambios en varias especies, aunque pueden tener intervalos grandes de confianza y verse afectadas por las variantes en las condiciones del censo. La declinación de los buitres africanos está bien documentada, pero hace falta el conocimiento sobre las tendencias recientes. Usamos las estimaciones de supervivencia tomadas de datos telemétricos recolectados durante seis años (principalmente del buitre Gyps africanus) y los conteos de transecto de siete especies carroñeras realizados durante ocho años en tres áreas protegidas en Tanzania. Estimamos las tendencias poblacionales con la combinación de análisis de supervivencia y el modelo de matriz Leslie Lefkovitch hecho con los datos telemétricos y usando modelos bayesianos de regresión lineal generalizada de efectos mixtos hechos con los datos de los transectos. Ambos métodos indicaron declinaciones significativas de Gyps africanus en los Parques Nacionales Ruaha y Nyerere. Sólo las estimaciones telemétricas sugirieron una declinación significativa en el Parque Nacional Katavi. Las tasas de encuentro calculadas a partir de los transectos también indicaron declinaciones de Torgos tracheliotos (38% de declinaciones anuales) y de Terathopius ecaudutus (18%) en el Parque Nacional Nyerere y de Trigonoceps occipitalis (19%) en el Parque Nacional Ruaha. Las muertes registradas e inferidas a partir de la telemetría sugieren que el envenenamiento es prevalente. Sin embargo, sólo se confirmaron seis muertes por envenenamiento de las 26 supuestas, lo que resalta los obstáculos para determinar la causa de muerte cuando se trabaja en paisajes amplios. A pesar de las declinaciones, nuestros datos proporcionan evidencia de que el sur de Tanzania tiene tasas actuales de encuentro con buitres africanos más altas que en cualquier otra parte del occidente de África. La prevención de declinaciones en el futuro dependerá principalmente de evitar el envenenamiento. Con base en nuestros resultados, sugerimos que el uso de técnicas múltiples incrementa el conocimiento sobre las tendencias poblacionales a corto plazo.

Global effects of extreme temperatures on wild bumblebees.

Climate plays a key role in shaping population trends and determining the geographic distribution of species because of limits in species' thermal tolerance. An evaluation of species tolerance to temperature change can therefore help predict their potential spatial shifts and population trends triggered by ongoing global warming. We assessed inter- and intraspecific variations in heat resistance in relation to body mass, local mean temperatures, and evolutionary relationships in 39 bumblebee species, a major group of pollinators in temperate and cold ecosystems, across 3 continents, 6 biomes, and 20 regions (2386 male specimens). Based on experimental bioassays, we measured the time before heat stupor of bumblebee males at a heatwave temperature of 40 °C. Interspecific variability was significant, in contrast to interpopulational variability, which was consistent with heat resistance being a species-specific trait. Moreover, cold-adapted species are much more sensitive to heat stress than temperate and Mediterranean species. Relative to their sensitivity to extreme temperatures, our results help explain recent population declines and range shifts in bumblebees following climate change.

Efectos Globales de las Temperaturas Extremas sobre Abejorros Silvestres Resumen El clima juega un papel importante en la configuración de las tendencias poblacionales y en la determinación de la distribución geográfica de las especies debido a los límites de la tolerancia térmica y al agua que tiene cada especie. Por lo tanto, una evaluación de la tolerancia de las especies al cambio térmico puede ayudar a predecir los potenciales cambios espaciales y las tendencias poblacionales detonadas por el calentamiento global en curso. Evaluamos las variaciones inter- e intraespecíficas de la resistencia al calor en relación con la masa corporal, temperaturas locales promedio y las relaciones evolutivas para 39 especies de abejorros, un grupo primordial de polinizadores en ecosistemas templados y fríos, en tres continentes, seis biomas y 20 regiones (2,386 especímenes machos). Con base en bioanálisis experimentales, medimos el tiempo previo al letargo por calor de los abejorros machos a temperaturas de 40 °C, típicas de una ola de calor. La variabilidad interespecífica fue significativa, en contraste con la variabilidad interpoblacional, lo cual fue consistente con el hecho de que la resistencia al calor sea una característica específica de la especie. Además, las especies adaptadas al frío son mucho más sensibles al estrés por calor que las especies de clima templado o Mediterráneo. En relación con la sensibilidad a las temperaturas extremas, nuestros resultados ayudan a explicar las recientes declinaciones poblacionales y cambios en la distribución de los abejorros posteriores al cambio climático.

Effects of the Argentine ant venom on terrestrial amphibians.

Invasive species have major impacts on biodiversity and are one of the primary causes of amphibian decline and extinction. Unlike other top ant invaders that negatively affect larger fauna via chemical defensive compounds, the Argentine ant (Linepithema humile) does not have a functional sting. Nonetheless, it deploys defensive compounds against competitors and adversaries. We estimated levels of ant aggression toward 3 native terrestrial amphibians by challenging juveniles in field ant trails and in lab ant foraging arenas. We measured the composition and quantities of toxin in L. humile by analyzing pygidial glands and whole-body contents. We examined the mechanisms of toxicity in juvenile amphibians by quantifying the toxin in amphibian tissues, searching for histological damages, and calculating toxic doses for each amphibian species. To determine the potential scope of the threat to amphibians, we used global databases to estimate the number, ranges, and conservation status of terrestrial amphibian species with ranges that overlap those of L. humile. Juvenile amphibians co-occurring spatially and temporally with L. humile die when they encounter L. humile on an ant trail. In the lab, when a juvenile amphibian came in contact with L. humile the ants reacted quickly to spray pygidial-gland venom onto the juveniles. Iridomyrmecin was the toxic compound in the spray. Following absorption, it accumulated in brain, kidney, and liver tissue. Toxic dose for amphibian was species dependent. Worldwide, an estimated 817 terrestrial amphibian species overlap in range with L. humile, and 6.2% of them are classified as threatened. Our findings highlight the high potential of L. humile venom to negatively affect amphibian juveniles and provide a basis for exploring the largely overlooked impacts this ant has in its wide invasive range.

Efectos del Veneno de la Hormiga Argentina sobre los Anfibios Terrestres Resumen Las especies invasoras tienen un impacto importante sobre la biodiversidad y son una de las causas principales del declive y extinción de los anfibios. A diferencia de otras hormigas super-invasoras que afectan negativamente a animales más grandes por medio de compuestos químicos de defensa, la hormiga argentina (Linepithema humile) no tiene unaguijón funcional. Sin embargo, esta hormiga despliega compuestos defensivos contra sus competidores y adversarios. Estimamos los niveles de agresión de las hormigas hacia tres anfibios terrestres nativos exponiendo a los anfibios juveniles en pistas de hormigas en el campo y en las arenas de forrajeo de las hormigas en el laboratorio. Medimos la composición y las cantidades de toxina que presenta L. humile por medio del análisis de las glándulas pigidiales y el contenido en el cuerpo completo. Examinamos los mecanismos de la toxicidad en los anfibios juveniles cuantificando la toxina en el tejido del anfibio, buscando daños histológicos y calculando las dosis tóxicas para cada especie de anfibio. Para determinar el alcance potencial de la amenaza para los anfibios usamos bases de datos mundiales para estimar el número, distribución y estado de conservación de las especies terrestres de anfibios con distribuciones que se solapan con la de L. humile. Los anfibios juveniles que co-ocurren temporal y espacialmente con L. humile mueren al encontrarse con esta especie de hormiga en sus pistas. En el laboratorio, cuando un anfibio juvenil entró en contacto con L. humile, las hormigas reaccionaron rápidamente rociando a estos juveniles con veneno proveniente de las glándulas pigidiales. La iridomyrmecina fue el compuesto tóxico que encontramos en las glándulas pigidiales. Después de ser absorbida por la piel del anfibio, se acumuló en el cerebro, los riñones y el hígado. La dosis tóxica para los anfibios depende de la especie. A nivel mundial, se estima que 817 especies de anfibios terrestres tienen una distribución que se solapa con la de L. humile, y el 6.2% de estas especies se encuentran clasificadas como amenazadas. Nuestros hallazgos resaltan el potencial alto del veneno de L. humile para tener efectos negativos sobre los anfibios juveniles y también proporcionan una base para la exploración de los impactos de esta hormiga en su amplio rango invasivo, los cuales generalmente son ignorados.

The effect of summer drought on the predictability of local extinctions in a butterfly metapopulation.

The ecological impacts of extreme climatic events on population dynamics and community composition are profound and predominantly negative. Using extensive data of an ecological model system, we tested whether predictions from ecological models remain robust when environmental conditions are outside the bounds of observation. We observed a 10-fold demographic decline of the Glanville fritillary butterfly (Melitaea cinxia) metapopulation on the Åland islands, Finland in the summer of 2018 and used climatic and satellite data to demonstrate that this year was an anomaly with low climatic water balance values and low vegetation productivity indices across Åland. Population growth rates were strongly associated with spatiotemporal variation in climatic water balance. Covariates shown previously to affect the extinction probability of local populations in this metapopulation were less informative when populations were exposed to severe drought during the summer months. Our results highlight the unpredictable responses of natural populations to extreme climatic events.

El Efecto de la Sequía Estival sobre la Previsibilidad de las Extinciones Locales en una Metapoblación de Mariposas Resumen Los impactos ecológicos de los eventos climáticos extremos sobre las dinámicas metapoblacionales y la composición de la comunidad son profundos y predominantemente negativos. Con los extensos datos de un sistema de modelos ecológicos probamos si las predicciones de los modelos ecológicos todavía son sólidos cuando las condiciones ambientales se encuentran fuera de los límites de observación. Observamos una declinación demográfica ocurrir diez veces en la metapoblación de la mariposa Melitaea cinxia en las Islas Aland de Finlandia durante el verano de 2018. Usamos datos climáticos y satelitales para demostrar que ese año fue una anomalía al contar con valores bajos de balance hídrico e índices bajos de productividad de la vegetación en todas las islas. Las tasas de crecimiento poblacional estuvieron fuertemente asociadas con la variación espaciotemporal del balance hídrico climático. Las covarianzas que previamente han afectado a la probabilidad de extinción de las poblaciones locales de esta metapoblación fueron menos informativas cuando las poblaciones estuvieron expuestas a sequías severas durante los meses de verano. Nuestros resultados resaltan las respuestas impredecibles de las poblaciones naturales ante los eventos climáticos extremos.

Complex and nonlinear climate-driven changes in freshwater insect communities over 42 years.

The ongoing biodiversity crisis becomes evident in the widely observed decline in abundance and diversity of species, profound changes in community structure, and shifts in species' phenology. Insects are among the most affected groups, with documented decreases in abundance up to 76% in the last 25-30 years in some terrestrial ecosystems. Identifying the underlying drivers is a major obstacle as most ecosystems are affected by multiple stressors simultaneously and in situ measurements of environmental variables are often missing. In our study, we investigated a headwater stream belonging to the most common stream type in Germany located in a nature reserve with no major anthropogenic impacts except climate change. We used the most comprehensive quantitative long-term data set on aquatic insects available, which includes weekly measurements of species-level insect abundance, daily water temperature and stream discharge as well as measurements of additional physicochemical variables for a 42-year period (1969-2010). Overall, water temperature increased by 1.88 °C and discharge patterns changed significantly. These changes were accompanied by an 81.6% decline in insect abundance, but an increase in richness (+8.5%), Shannon diversity (+22.7%), evenness (+22.4%), and interannual turnover (+34%). Moreover, the community's trophic structure and phenology changed: the duration of emergence increased by 15.2 days, whereas the peak of emergence moved 13.4 days earlier. Additionally, we observed short-term fluctuations (<5 years) in almost all metrics as well as complex and nonlinear responses of the community toward climate change that would have been missed by simply using snapshot data or shorter time series. Our results indicate that climate change has already altered biotic communities severely even in protected areas, where no other interacting stressors (pollution, habitat fragmentation, etc.) are present. This is a striking example of the scientific value of comprehensive long-term data in capturing the complex responses of communities toward climate change.

Cambios Complejos y No Lineales Causados por el Clima en Comunidades de Insectos de Agua Dulce durante 42 Años Resumen La continua crisis de la biodiversidad se vuelve evidente en la ampliamente documentada declinación en la abundancia y diversidad de especies, cambios profundos en la estructura de las comunidades y modificaciones en la fenología de las especies. Los insectos se encuentran entre los grupos más afectados; se han documentado reducciones en la abundancia de hasta el 76% en los últimos 25-30 años en algunos ecosistemas terrestres. La identificación de los causantes subyacentes es un gran obstáculo porque la mayoría de los ecosistemas están afectados por varios factores estresantes simultáneamente y con frecuencia faltan las medidas in situ de las variables ambientales. Investigamos un flujo naciente perteneciente al tipo de arroyo más común en Alemania ubicado dentro de una reserva natural sin impactos antropogénicos importantes a excepción del cambio climático. Usamos el conjunto más completo disponible de datos cuantitativos de largo plazo para insectos acuáticos que incluye las medidas semanales de abundancia de insectos a nivel especie, las medidas diarias de la temperatura del agua y la descarga del flujo y las medidas de variables físico-químicas adicionales durante 42 años (1969 - 2010). En general, la temperatura del agua incrementó 1.88°C y los patrones de descarga cambiaron significativamente. Estos cambios estuvieron acompañados por una declinación del 81.6% en la abundancia de insectos, pero también de un incremento en la riqueza (+8.5%), la diversidad Shannon (+22.7%), la uniformidad (+22.4%) y la renovación interanual (+34%). Además, la estructura trófica y la fenología de la comunidad cambiaron: la duración del surgimiento incrementó en 15.2 días y el pico del surgimiento ocurrió con 13.4 días de anticipación. Observamos fluctuaciones a corto plazo (<5 años) en casi todas las medidas, así como respuestas complejas y no lineales de la comunidad hacia el cambio climático que podrían haber sido ignoradas si sólo se usaran datos instantáneos o series de tiempo más cortas. Nuestros resultados indican que el cambio climático ya ha alterado seriamente a las comunidades bióticas, incluso en áreas protegidas en las que no están presentes otros factores estresantes en interacción (contaminación, fragmentación del hábitat, etc.). Ésto es un ejemplo notable del valor científico que tienen los datos completos de escalas de tiempo a largo plazo para la captura de las respuestas complejas de las comunidades ante el cambio climático.

Anthropogenic threats to evolutionary heritage of angiosperms in the Netherlands through an increase in high-competition environments.

Present biodiversity comprises the evolutionary heritage of Earth's epochs. Lineages from particular epochs are often found in particular habitats, but whether current habitat decline threatens the heritage from particular epochs is unknown. We hypothesized that within a given region, humans threaten specifically habitats that harbor lineages from a particular geological epoch. We expect so because humans threaten environments that dominated and lineages that diversified during these epochs. We devised a new approach to quantify, per habitat type, diversification of lineages from different epochs. For Netherlands, one of the floristically and ecologically best-studied regions, we quantified the decline of habitat types and species in the past century. We defined habitat types based on vegetation classification and used existing ranking of decline of vegetation classes and species. Currently, most declining habitat types and the group of red-listed species are characterized by increased diversification of lineages dating back to Paleogene, specifically to Paleocene-Eocene and Oligocene. Among vulnerable habitat types with large representation of lineages from these epochs were sublittoral and eulittoral zones of temperate seas and 2 types of nutrient-poor, open habitats. These losses of evolutionary heritage would go unnoticed with classical measures of evolutionary diversity. Loss of heritage from Paleocene-Eocene became unrelated to decline once low competition, shade tolerance, and low proportion of non-Apiaceae were accounted for, suggesting that these variables explain the loss of heritage from Paleocene-Eocene. Losses of heritage from Oligocene were partly explained by decline of habitat types occupied by weak competitors and shade-tolerant species. Our results suggest a so-far unappreciated human threat to evolutionary heritage: habitat decline threatens descendants from particular epochs. If the trends persist into the future uncontrolled, there may be no habitats within the region for many descendants of evolutionary ancient epochs, such as Paleogene.

Amenazas Antropogénicas para la Herencia Evolutiva de las Angiospermas en los Países Bajos a partir del Incremento en los Ambientes de Competencia Elevada Resumen La biodiversidad actual abarca la herencia evolutiva de las épocas de la Tierra. Los linajes de épocas particulares se encuentran con frecuencia en hábitats particulares pero desconocemos si la declinación contemporánea de los hábitats amenaza a la herencia de una época en particular. Nuestra hipótesis supone que dentro de una región determinada, los humanos son una amenaza específica para los hábitats que albergan linajes de una época geológica particular. Suponemos esto pues los humanos amenazan a los ambientes y a los linajes que se diversificaron durante estas épocas. Diseñamos una nueva estrategia para cuantificar, por tipo de hábitat, la diversificación de los linajes de épocas distintas. Cuantificamos para los Países Bajos, una de las regiones mejor estudiada florística y ecológicamente, la declinación de los tipos de hábitat y de especies durante el siglo pasado. Definimos los tipos de hábitat con base en la clasificación de la vegetación y usamos las jerarquías existentes de la declinación de clases y especies de vegetación. Hoy en día, la mayoría de los tipos de hábitat en declinación y el grupo de especies en lista roja se caracterizan por la diversificación incrementada de los linajes que datan del Paleógeno, específicamente el Paleoceno-Eoceno y el Oligoceno. Entre los tipos de hábitat vulnerables con una gran representación de los linajes de estas épocas encontramos a la zona sublitoral e intermareal de los mares templados y dos tipos de hábitats abiertos con deficiencia de nutrientes. Estas pérdidas de linaje evolutivo pasarían desapercibidas con las medidas clásicas de la diversidad evolutiva. La pérdida de la herencia del Paleoceno-Eoceno dejó de estar relacionada con la declinación una vez que contabilizamos la baja competencia, la tolerancia a la sombra y la baja proporción de especies no pertenecientes a la familia Apiaceae, lo que sugiere que estas variables explican la pérdida de herencia del Paleoceno-Eoceno. La pérdida de herencia del Oligoceno estuvo explicada en parte por la declinación de los tipos de hábitat ocupados por competidores débiles y especies tolerantes a la sombra. Nuestros resultados sugieren una amenaza humana para la herencia evolutiva que todavía no ha sido apreciada: la declinación del hábitat amenaza a los descendientes de épocas particulares. Si en el futuro las tendencias siguen sin ser controladas, puede que no haya hábitats en la región para muchos de los descendientes evolutivos de épocas antiguas, como el Paleógeno.

Practitioner and scientist perceptions of successful amphibian conservation.

Conservation requires successful outcomes. However, success is perceived in many different ways depending on the desired outcome. Through a questionnaire survey, we examined perceptions of success among 355 scientists and practitioners working on amphibian conservation from over 150 organizations in more than 50 countries. We also sought to identify how different types of conservation actions and respondent experience and background influenced perceptions. Respondents identified 4 types of success: species and habitat improvements (84% of respondents); effective program management (36%); outreach initiatives such as education and public engagement (25%); and the application of science-based conservation (15%). The most significant factor influencing overall perceived success was reducing threats. Capacity building was rated least important. Perceptions were influenced by experience, professional affiliation, involvement in conservation practice, and country of residence. More experienced practitioners associated success with improvements to species and habitats and less so with education and engagement initiatives. Although science-based conservation was rated as important, this factor declined in importance as the number of programs a respondent participated in increased, particularly among those from less economically developed countries. The ultimate measure of conservation success-population recovery-may be difficult to measure in many amphibians; difficult to relate to the conservation actions intended to drive it; and difficult to achieve within conventional funding time frames. The relaunched Amphibian Conservation Action Plan provides a framework for capturing lower level processes and outcomes, identifying gaps, and measuring progress.

Measuring the impact of the pet trade on Indonesian birds.

The trade in wild animals involves one-third of the world's bird species and thousands of other vertebrate species. Although a few species are imperiled as a result of the wildlife trade, the lack of field studies makes it difficult to gauge how serious a threat it is to biodiversity. We used data on changes in bird abundances across space and time and information from trapper interviews to evaluate the effects of trapping wild birds for the pet trade in Sumatra, Indonesia. To analyze changes in bird abundance over time, we used data gathered over 14 years of repeated bird surveys in a 900-ha forest in southern Sumatra. In northern Sumatra, we surveyed birds along a gradient of trapping accessibility, from the edge of roads to 5 km into the forest interior. We interviewed 49 bird trappers in northern Sumatra to learn which species they targeted and how far they went into the forest to trap. We used prices from Sumatran bird markets as a proxy for demand and, therefore, trapping pressure. Market price was a significant predictor of species declines over time in southern Sumatra (e.g., given a market price increase of approximately $50, the log change in abundance per year decreased by 0.06 on average). This result indicates a link between the market-based pet trade and community-wide species declines. In northern Sumatra, price and change in abundance were not related to remoteness (distance from the nearest road). However, based on our field surveys, high-value species were rare or absent across this region. The median maximum distance trappers went into the forest each day was 5.0 km. This suggests that trapping has depleted bird populations across our remoteness gradient. We found that less than half of Sumatra's remaining forests are >5 km from a major road. Our results suggest that trapping for the pet trade threatens birds in Sumatra. Given the popularity of pet birds across Southeast Asia, additional studies are urgently needed to determine the extent and magnitude of the threat posed by the pet trade.

Reservoir-host amplification of disease impact in an endangered amphibian.

Emerging wildlife pathogens are an increasing threat to biodiversity. One of the most serious wildlife diseases is chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd), which has been documented in over 500 amphibian species. Amphibians vary greatly in their susceptibility to Bd; some species tolerate infection, whereas others experience rapid mortality. Reservoir hosts-species that carry infection while maintaining high abundance but are rarely killed by disease-can increase extinction risk in highly susceptible, sympatric species. However, whether reservoir hosts amplify Bd in declining amphibian species has not been examined. We investigated the role of reservoir hosts in the decline of the threatened northern corroboree frog (Pseudophryne pengilleyi) in an amphibian community in southeastern Australia. In the laboratory, we characterized the response of a potential reservoir host, the (nondeclining) common eastern froglet (Crinia signifera), to Bd infection. In the field, we conducted frog abundance surveys and Bd sampling for both P. pengilleyi and C. signifera. We built multinomial logistic regression models to test whether Crinia signifera and environmental factors were associated with P. pengilleyi decline. C. signifera was a reservoir host for Bd. In the laboratory, many individuals maintained intense infections (>1000 zoospore equivalents) over 12 weeks without mortality, and 79% of individuals sampled in the wild also carried infections. The presence of C. signifera at a site was strongly associated with increased Bd prevalence in sympatric P. pengilleyi. Consistent with disease amplification by a reservoir host, P. pengilleyi declined at sites with high C. signifera abundance. Our results suggest that when reservoir hosts are present, population declines of susceptible species may continue long after the initial emergence of Bd, highlighting an urgent need to assess extinction risk in remnant populations of other declined amphibian species.

Developments in amphibian captive breeding and reintroduction programs.

Captive breeding and reintroduction remain high profile but controversial conservation interventions. It is important to understand how such programs develop and respond to strategic conservation initiatives. We analyzed the contribution to conservation made by amphibian captive breeding and reintroduction since the launch of the International Union for Conservation of Nature (IUCN) Amphibian Conservation Action Plan (ACAP) in 2007. We assembled data on amphibian captive breeding and reintroduction from a variety of sources including the Amphibian Ark database and the IUCN Red List. We also carried out systematic searches of Web of Science, JSTOR, and Google Scholar for relevant literature. Relative to data collected from 1966 to 2006, the number of species involved in captive breeding and reintroduction projects increased by 57% in the 7 years since release of the ACAP. However, there have been relatively few new reintroductions over this period; most programs have focused on securing captive-assurance populations (i.e., species taken into captivity as a precaution against extinctions in the wild) and conservation-related research. There has been a shift to a broader representation of frogs, salamanders, and caecilians within programs and an increasing emphasis on threatened species. There has been a relative increase of species in programs from Central and South America and the Caribbean, where amphibian biodiversity is high. About half of the programs involve zoos and aquaria with a similar proportion represented in specialist facilities run by governmental or nongovernmental agencies. Despite successful reintroduction often being regarded as the ultimate milestone for such programs, the irreversibility of many current threats to amphibians may make this an impractical goal. Instead, research on captive assurance populations may be needed to develop imaginative solutions to enable amphibians to survive alongside current, emerging, and future threats.

Metabolism of aceclofenac in cattle to vulture-killing diclofenac.

The nonsteroidal anti-inflammatory drug (NSAID) diclofenac is highly toxic to Gyps vultures, and its recent widespread use in South Asia caused catastrophic declines in at least 3 scavenging raptors. The manufacture of veterinary formulations of diclofenac has since been banned across the region with mixed success. However, at least 12 other NSAIDs are available for veterinary use in South Asia. Aceclofenac is one of these compounds, and it is known to metabolize into diclofenac in some mammal species. The metabolic pathway of aceclofenac in cattle, the primary food of vultures in South Asia, is unknown. We gave 6 cattle the recommended dose of aceclofenac (2 mg/kg), collected blood thereafter at intervals for up to 12 h, and used liquid chromatography with mass spectrometry in a pharmacokinetic analysis of aceclofenac and diclofenac in the plasma. Nearly all the aceclofenac administered to the cattle was very rapidly metabolized into diclofenac. At 2 h, half the aceclofenac had been converted into diclofenac, and at 12 h four-fifths of the aceclofenac had been converted into diclofenac. Therefore, administering aceclofenac to livestock poses the same risk to vultures as administering diclofenac to livestock. This, coupled with the risk that aceclofenac may replace diclofenac in the veterinary market, points to the need for an immediate ban on all aceclofenac formulations that can be used to treat livestock. Without such a ban, the recovery of vultures across South Asia will not be successful.

Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations.

Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies. We experimentally investigated intraspecific differences in host sensitivity to Bd across 10 populations of wood frogs (Lithobates sylvaticus) raised from eggs to metamorphosis. We exposed the post-metamorphic wood frogs to Bd and monitored survival for 30 days under controlled laboratory conditions. Populations differed in overall survival and mortality rate. Infection load also differed among populations but was not correlated with population differences in risk of mortality. Such population-level variation in sensitivity to Bd may result in reservoir populations that may be a source for the transmission of Bd to other sensitive populations or species. Alternatively, remnant populations that are less sensitive to Bd could serve as sources for recolonization after epidemic events.

Inferring the nature of anthropogenic threats from long-term abundance records.

Diagnosing the processes that threaten species persistence is critical for recovery planning and risk forecasting. Dominant threats are typically inferred by experts on the basis of a patchwork of informal methods. Transparent, quantitative diagnostic tools would contribute much-needed consistency, objectivity, and rigor to the process of diagnosing anthropogenic threats. Long-term census records, available for an increasingly large and diverse set of taxa, may exhibit characteristic signatures of specific threatening processes and thereby provide information for threat diagnosis. We developed a flexible Bayesian framework for diagnosing threats on the basis of long-term census records and diverse ancillary sources of information. We tested this framework with simulated data from artificial populations subjected to varying degrees of exploitation and habitat loss and several real-world abundance time series for which threatening processes are relatively well understood: bluefin tuna (Thunnus maccoyii) and Atlantic cod (Gadus morhua) (exploitation) and Red Grouse (Lagopus lagopus scotica) and Eurasian Skylark (Alauda arvensis) (habitat loss). Our method correctly identified the process driving population decline for over 90% of time series simulated under moderate to severe threat scenarios. Successful identification of threats approached 100% for severe exploitation and habitat loss scenarios. Our method identified threats less successfully when threatening processes were weak and when populations were simultaneously affected by multiple threats. Our method selected the presumed true threat model for all real-world case studies, although results were somewhat ambiguous in the case of the Eurasian Skylark. In the latter case, incorporation of an ancillary source of information (records of land-use change) increased the weight assigned to the presumed true model from 70% to 92%, illustrating the value of the proposed framework in bringing diverse sources of information into a common rigorous framework. Ultimately, our framework may greatly assist conservation organizations in documenting threatening processes and planning species recovery.

Effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus.

The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. Recent studies show that sodium chloride (NaCl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. We investigated whether similar results can be obtained by adding salt to water bodies in the field. We increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water bodies with close to 0 ppt and monitored salinity for 18 months. Captively bred tadpoles of green and golden bell frog (Litoria aurea) were released into each water body and their development, levels of B. dendrobatidis infection, and survival were monitored at 1, 4, and 12 months. The effect of salt on the abundance of nontarget organisms was also investigated in before and after style analyses. Salinities remained constant over time with little intervention. Hosts in water bodies with 4 ppt salt had a significantly lower prevalence of chytrid infection and higher survival, following metamorphosis, than hosts in 0 ppt salt. Tadpoles in the 4 ppt group were smaller in length after 1 month in the release site than those in the 0 and 2 ppt groups, but after metamorphosis body size in all water bodies was similar . In water bodies with 4 ppt salt, the abundance of dwarf tree frogs (Litoria fallax), dragonfly larvae, and damselfly larvae was lower than in water bodies with 0 and 2 ppt salt, which could have knock-on effects for community structure. Based on our results, salt may be an effective field-based B. dendrobatidis mitigation tool for lentic amphibians that could contribute to the conservation of numerous susceptible species. However, as in all conservation efforts, these benefits need to be weighed against negative effects on both target and nontarget organisms.

Biogeographical and taxonomic biases in tropical forest fragmentation research.

Despite several decades of research on the effects of fragmentation and habitat change on biodiversity, there remain strong biases in the geographical regions and taxonomic species studied. The knowledge gaps resulting from these biases are of particular concern if the forests most threatened with modification are also those for which the effects of such change are most poorly understood. To quantify the nature and magnitude of such biases, we conducted a systematic review of the published literature on forest fragmentation in the tropics for the period 1980-2012. Studies included focused on any type of response of single species, communities, or assemblages of any taxonomic group to tropical forest fragmentation and on fragmentation-related changes to forests. Of the 853 studies we found in the SCOPUS database, 64% were conducted in the Neotropics, 13% in Asia, 10% in the Afrotropics, and 5% in Australasia. Thus, although the Afrotropics is subject to the highest rates of deforestation globally, it was the most disproportionately poorly studied biome. Significant taxonomic biases were identified. Of the taxonomic groups considered, herpetofauna was the least studied in the tropics, particularly in Africa. Research examining patterns of species distribution was by far the most common type (72%), and work focused on ecological processes (28%) was rare in all biomes, but particularly in the Afrotropics and for fauna. We suggest research efforts be directed toward less-studied biogeographic regions, particularly where the threat of forest fragmentation continues to be high. Increased research investment in the Afrotropics will be important to build knowledge of threats and inform responses in a region where almost no efforts to restore its fragmented landscapes have yet begun and forest protection is arguably most tenuous.

Occupancy patterns of regionally declining grassland sparrow populations in a forested Pennsylvania landscape.

Organisms can be affected by processes in the surrounding landscape outside the boundary of habitat areas and by local vegetation characteristics. There is substantial interest in understanding how these processes affect populations of grassland birds, which have experienced substantial population declines. Much of our knowledge regarding patterns of occupancy and density stem from prairie systems, whereas relatively little is known regarding how occurrence and abundance of grassland birds vary in reclaimed surface mine grasslands. Using distance sampling and single-season occupancy models, we investigated how the occupancy probability of Grasshopper (Ammodramus savannarum) and Henslow's Sparrows (A. henslowii) on 61 surface mine grasslands (1591 ha) in Pennsylvania changed from 2002 through 2011 in response to landscape, grassland, and local vegetation characteristics . A subset (n = 23; 784 ha) of those grasslands were surveyed in 2002, and we estimated changes in sparrow density and vegetation across 10 years. Grasshopper and Henslow's Sparrow populations declined 72% and 49%, respectively from 2002 to 2011, whereas overall woody vegetation density increased 2.6 fold. Henslow's Sparrows avoided grasslands with perimeter-area ratios ≥0.141 km/ha and woody shrub densities ≥0.04 shrubs/m(2). Both species occupied grasslands ≤13 ha, but occupancy probability declined with increasing grassland perimeter-area ratio and woody shrub density. Grassland size, proximity to nearest neighboring grassland (x = 0.2 km), and surrounding landscape composition at 0.5, 1.5, and 3.0 km were not parsimonious predictors of occupancy probability for either species. Our results suggest that reclaimed surface mine grasslands, without management intervention, are ephemeral habitats for Grasshopper and Henslow's Sparrows. Given the forecasted decline in surface coal production for Pennsylvania, it is likely that both species will continue to decline in our study region for the foreseeable future.

Interventions for reducing extinction risk in chytridiomycosis-threatened amphibians.

Wildlife diseases pose an increasing threat to biodiversity and are a major management challenge. A striking example of this threat is the emergence of chytridiomycosis. Despite diagnosis of chytridiomycosis as an important driver of global amphibian declines 15 years ago, researchers have yet to devise effective large-scale management responses other than biosecurity measures to mitigate disease spread and the establishment of disease-free captive assurance colonies prior to or during disease outbreaks. We examined the development of management actions that can be implemented after an epidemic in surviving populations. We developed a conceptual framework with clear interventions to guide experimental management and applied research so that further extinctions of amphibian species threatened by chytridiomycosis might be prevented. Within our framework, there are 2 management approaches: reducing Batrachochytrium dendrobatidis (the fungus that causes chytridiomycosis) in the environment or on amphibians and increasing the capacity of populations to persist despite increased mortality from disease. The latter approach emphasizes that mitigation does not necessarily need to focus on reducing disease-associated mortality. We propose promising management actions that can be implemented and tested based on current knowledge and that include habitat manipulation, antifungal treatments, animal translocation, bioaugmentation, head starting, and selection for resistance. Case studies where these strategies are being implemented will demonstrate their potential to save critically endangered species.

Climate change, multiple stressors, and the decline of ectotherms.

Climate change is believed to be causing declines of ectothermic vertebrates, but there is little evidence that climatic conditions associated with declines have exceeded critical (i.e., acutely lethal) maxima or minima, and most relevant studies are correlative, anecdotal, or short-term (hours). We conducted an 11-week factorial experiment to examine the effects of temperature (22 °C or 27 °C), moisture (wet or dry), and atrazine (an herbicide; 0, 4, 40, 400 µg/L exposure as embryos and larvae) on the survival, growth, behavior, and foraging rates of postmetamorphic streamside salamanders (Ambystoma barbouri), a species of conservation concern. The tested climatic conditions were between the critical maxima and minima of streamside salamanders; thus, this experiment quantified the long-term effects of climate change within the noncritical range of this species. Despite a suite of behavioral adaptations to warm and dry conditions (e.g., burrowing, refuge use, huddling with conspecifics, and a reduction in activity), streamside salamanders exhibited significant loss of mass and significant mortality in all but the cool and moist conditions, which were closest to the climatic conditions in which they are most active in nature. A temperature of 27 °C represented a greater mortality risk than dry conditions; death occurred rapidly at this temperature and more gradually under cool and dry conditions. Foraging decreased under dry conditions, which suggests there were opportunity costs to water conservation. Exposure to the herbicide atrazine additively decreased water-conserving behaviors, foraging efficiency, mass, and time to death. Hence, the hypothesis that moderate climate change can cause population declines is even more plausible under scenarios with multiple stressors. These results suggest that climate change within the noncritical range of species and pollution may reduce individual performance by altering metabolic demands, hydration, and foraging effort and may facilitate population declines of amphibians and perhaps other ectothermic vertebrates.

Roles of patch characteristics, drought frequency, and restoration in long-term trends of a widespread amphibian.

Despite the high profile of amphibian declines and the increasing threat of drought and fragmentation to aquatic ecosystems, few studies have examined long-term rates of change for a single species across a large geographic area. We analyzed growth in annual egg-mass counts of the Columbia spotted frog (Rana luteiventris) across the northwestern United States, an area encompassing 3 genetic clades. On the basis of data collected by multiple partners from 98 water bodies between 1991 and 2011, we used state-space and linear-regression models to measure effects of patch characteristics, frequency of summer drought, and wetland restoration on population growth. Abundance increased in the 2 clades with greatest decline history, but declined where populations are considered most secure. Population growth was negatively associated with temporary hydroperiods and landscape modification (measured by the human footprint index), but was similar in modified and natural water bodies. The effect of drought was mediated by the size of the water body: populations in large water bodies maintained positive growth despite drought, whereas drought magnified declines in small water bodies. Rapid growth in restored wetlands in areas of historical population declines provided strong evidence of successful management. Our results highlight the importance of maintaining large areas of habitat and underscore the greater vulnerability of small areas of habitat to environmental stochasticity. Similar long-term growth rates in modified and natural water bodies and rapid, positive responses to restoration suggest pond construction and other forms of management can effectively increase population growth. These tools are likely to become increasingly important to mitigate effects of increased drought expected from global climate change. Papeles de las Características del Fragmento, Frecuencia de Sequía y Restauración en las Tendencias a Largo Plazo de un Anfibio Ampliamente Distribuido.

Formas extremas de sofrimento psíquico na infância e adolescência atuais / Extreme forms of psychic pain in current childhood and adolescence / Formas extremas del padecimiento psíquico en la infancia y la adolescencia actuales

O autor considera que o alarmante crescimento do número de suicídios de adolescentes constitui a ponta de um iceberg muito mais amplo: o sofrimento profundo, muitas vezes naturalizado, das gerações mais jovens. É um sofrimento em que o olhar sociológico costuma verificar o fracasso dos adultos na transmissão de um legado que permita a inclusão dos recém-chegados no corpo social. Nós, psicanalistas, registramos - paradoxalmente ­ um êxito nessa conjuntura inquietante: aquele que corresponde às tendências filicidas e destrutivas para com os jovens, as quais autores como Raskovsky, Winnicott e Lacan exploraram em suas análises. São examinadas algumas peculiaridades sintomáticas da adolescência atual. Examina-se a orientação fornecida por algumas observações de Freud e Lacan com o intuito de acomodá-las e processá-las no dispositivo analítico (AU)

The author considers that the alarming growth in the number of adolescent suicides is the tip of a much larger iceberg: the deep suffering, often accepted as natural, of the younger generations. It is a pain in which the sociological analysis usually finds the adults' failure in conveying a legacy that enables inclusion of the newcomers in the social body. We psychoanalysts register ­ paradoxically ­ a success in this disturbing situation: the one that corresponds to filicidal and destructive impulses towards the youngsters, which authors such as Raskovsky, Winnicott and Lacan explored in their work. Some symptomatic peculiarities of current adolescence are examined. Guidance provided by some Freudian and Lacanian observations is examined to accommodate and process them in the analytical field (AU)

El autor considera que el crecimiento alarmante de las cifras de suicidio adolescente constituye la punta de un iceberg mucho más extendido: el profundo padecimiento, muchas veces naturalizado, de las generaciones jóvenes. Es un padecimiento en el que la mirada sociológica suele verificar el fracaso de los adultos en la transmisión de un legado que permita incluir a los recién llegados en el cuerpo social. Los psicoanalistas registramos ­ paradojalmente ­ un éxito en esta coyuntura inquietante: el que corresponde a las tendencias filicidas y destructivas para con los jóvenes, que han explorado en sus desarrollos autores como Raskovsky, Winnicott El autor considera que el crecimiento alarmante de las cifras de suicidio adolescente constituye la punta de un iceberg mucho más extendido: el profundo padecimiento, muchas veces naturalizado, de las generaciones jóvenes. Es un padecimiento en el que la mirada sociológica suele verificar el fracaso de los adultos en la transmisión de un legado que permita incluir a los recién llegados en el cuerpo social. Los psicoanalistas registramos ­ paradojalmente ­ un éxito en esta coyuntura inquietante: el que corresponde a las tendencias filicidas y destructivas para con los jóvenes, que han explorado en sus desarrollos autores como Raskovsky, Winnicott (AU)