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Actuarial senescence, the increase in adult mortality risk with increasing age, is a widespread phenomenon across the animal kingdom. Although between-species variation in the rate of increase in mortality as organisms age (i.e. ageing rate) is now well documented, the occurrence of variation in ageing rate within a given species remains much more debatable. We evaluated the level of within-species variation in ageing rate in four populations of the southern Darwin’s frog (Rhinoderma darwinii) from Chile. Our results revealed strong among-population variation in ageing rates, and these were correlated with the population-specific generation time. A higher ageing rate occurred in populations where individuals exhibited a faster pace of life. Our results, along with recent studies in evolutionarily distant amphibian species, indicate that there can be substantial within-species variation in the rate of ageing, highlighting amphibians as emerging models to study the patterns and mechanisms of intraspecific variation in ageing rate.

Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 populations (77 species) of nonavian reptiles and amphibians. We test hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life history contribute to demographic aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates compared with endotherms and include phylogenetically widespread evidence of negligible aging. Protective phenotypes and life-history strategies further explain macroevolutionary patterns of aging. Analyzing ectothermic tetrapods in a comparative context enhances our understanding of the evolution of aging.

Sex-related differences in mortality are widespread in the animal kingdom. Although studies have shown that sex determinationsystems might drive lifespan evolution, sex chromosome influence on aging rates have not been investigated so far, likely due toan apparent lack of demographic data from clades including both XY (with heterogametic males) and ZW (heterogametic females)systems. Taking advantage of a unique collection of capture–recapture datasets in amphibians, a vertebrate group where XY andZW systems have repeatedly evolved over the past 200 million years, we examined whether sex heterogamy can predict sexdifferences in aging rates and lifespans. We showed that the strength and direction of sex differences in aging rates (and notlifespan) differ between XY and ZW systems. Sex-specific variation in aging rates was moderate within each system, but agingrates tended to be consistently higher in the heterogametic sex. This led to small but detectable effects of sex chromosome systemon sex differences in aging rates in our models. Although preliminary, our results suggest that exposed recessive deleteriousmutations on the X/Z chromosome (the “unguarded X/Z effect”) or repeat-rich Y/W chromosome (the “toxic Y/W effect”) couldaccelerate aging in the heterogametic sex in some vertebrate clades., C was supported asa postdoctoral researcher by the Vanier-Banting postdoctoral fellowship program and the Swiss National Science Foundation (SNF grant number 31003A_182265).

Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused the greatest known loss of biodiversity due to an infectious disease. We used Bd infection data from quantitative real-time PCR (qPCR) assays of amphibian skin swabs collected across Chile during 2008–2018 to model Bd occurrence with the aim to determine bioclimatic and anthropogenic variables associated with Bd infection. Also, we used Bd presence/absence records to identify geographical Bd high-risk areas and compare Bd prevalence and infection loads between amphibian families, ecoregions, and host ecology. Data comprised 4155 Bd-specific qPCR assays from 162 locations across a latitudinal gradient of 3700 km (18º to 51ºS). Results showed a significant clustering of Bd associated with urban centres and anthropogenically highly disturbed ecosystems in central-south Chile. Both Bd prevalence and Bd infection loads were higher in aquatic than terrestrial amphibian species. Our model indicated positive associations of Bd prevalence with altitude, temperature, precipitation and human-modified landscapes. Also, we found that macroscale drivers, such as land use change and climate, shape the occurrence of Bd at the landscape level. Our study provides with new evidence that can improve the effectiveness of strategies to mitigate biodiversity loss due to amphibian chytridiomycosis.

Forest management can be used to increase the local abundance of species of conservation concern. To achieve this goal, managers must be sure that the relationships between the targeted forest attributes and the focal species abundance are based on robust data and inference. This is a critical issue as the same forest attributes could have opposing effects on species abundance and the detectability of individuals, impairing our ability to detect useful habitat quality surrogates and to provide correct forest management recommendations. Using spatially stratified capture-recapture models (a.k.a. multinomial N-mixture models), we evaluated the effects of stand-level forest attributes on detection probability and local abundance for the endangered Southern Darwin’s frog (Rhinoderma darwinii), a forest-specialist and fully terrestrial amphibian endemic to the South American temperate forest. Our results show that an increase of stand basal area and a decrease of daily microclimatic fluctuation (i.e. an increase in structural complexity) were positively associated with the local abundance of R. darwinii. These stand-level forest attributes also explained the among-population variation in detection probability, although the relationships were opposite to those for abundance. Consequently, an analysis of raw frog counts (i.e. not adjusted for imperfect detection) did not reveal all the factors associated with local abundance. Our results provide further support to previous claims that raw counts of individuals should not be used, generally, as a proxy of abundance in species inhabiting forest ecosystems and elsewhere. More importantly, the opposite effect of forest attributes on abundance and detectability observed in our study highlights the need to use methods that quantify species-habitat relationships in a robust way and which take habitat-specific imperfect detection into account.

When facing an emerging infectious disease of conservation concern, we often have little information on the nature of the host-parasite interaction to inform management decisions. However, it is becoming increasingly clear that the life-history strategies of host species can be predictive of individual- and population-level responses to infectious disease, even without detailed knowledge on the specifics of the host-parasite interaction. Here, we argue that a deeper integration of life-history theory into disease ecology is timely and necessary to improve our capacity to understand, predict and mitigate the impact of endemic and emerging infectious diseases in wild populations. Using wild vertebrates as an example, we show that host life-history characteristics influence host responses to parasitism at different levels of organisation, from individuals to communities. We also highlight knowledge gaps and future directions for the study of life-history and host responses to parasitism. We conclude by illustrating how this theoretical insight can inform the monitoring and control of infectious diseases in wildlife.

Sexual signals in different animals are expected to be dimorphic when both sexes signal, but cases of monomorphism are known to occur, and we lack a clear understanding about the factors that modulate the level of sexual dimorphism in signals. In this study, we evaluated the hypothesis that the lack of dimorphism in sexual signals might evolve in systems experiencing temporal changing conditions of intra-sexual competition. We used the Darwin’s frog (Rhinoderma darwinii), a species with paternal care, as a model. We compared advertisement calls and examined call distinctiveness among females, pregnant and non-pregnant males in a wild population from Chiloe island, Chile. We also recorded the vocal activity of both sexes along the reproductive season. Additionally, we compared the acoustic properties of their advertisement calls in terms of sexual distinctiveness and individual repeatability. We found that the proportion of females and pregnant males vocalizing changed over time following distinct patterns. Females produced calls with lower dominant frequency and longer note and call durations than males, and these acoustic differences were related to body size differences between sexes, but only dominant frequency contributed significantly to the distinctiveness of calls between sexes. Also, individual repeatability was high, indicating that calling can be relevant for social recognition. Overall, our results suggest that mutual selective pressures could be involved in the limited dimorphism of the advertisement calls in Darwin’s frogs, as the sex ratio of individuals vocalizing (i.e. females vs. reproductive males) is reversed along the breeding period. Whether sexually monomorphic signals are evidence of adaptive mutual choice or a by-product of genetic constraints on females remains as an open question. In species with exclusive parental care of males, it would be expected that males and females alternate their reproductive availability while performing slightly differentiated sexual signals. Using acoustic recordings and capture-recapture data of the Darwin’s frog, we found that advertisement calls of this frog tend to be monomorphic. Interestingly, the males performing parental care were calling actively and the population had a clear bias in the number of males. Males and females of this endangered frog called actively, but the vocalization rate of each sex peaked at different times along the breeding season. These findings open new questions about the mechanisms of sexual recognition under restricted signal dimorphism.

Globalized infectious diseases are causing species declines worldwide, but their source often remains elusive. We used whole-genome sequencing to solve the spatiotemporal origins of the most devastating panzootic to date, caused by the fungus Batrachochytrium dendrobatidis, a proximate driver of global amphibian declines. We traced the source of B. dendrobatidis to the Korean peninsula, where one lineage, BdASIA-1, exhibits the genetic hallmarks of an ancestral population that seeded the panzootic. We date the emergence of this pathogen to the early 20th century, coinciding with the global expansion of commercial trade in amphibians, and we show that intercontinental transmission is ongoing. Our findings point to East Asia as a geographic hotspot for B. dendrobatidis biodiversity and the original source of these lineages that now parasitize amphibians worldwide., S.J.O., T.W.J.G., L.Br., A.Lo., A.A.C., D.S.S., E.A.C., C.M., J.B., D.M.A., F.C., and M.C.F. were supported through NERC (standard grant NE/K014455/1). S.J.O. acknowledges a Microsoft Azure for Research Sponsorship (subscription ID: ab7cd695-49cf-4a83-910a-ef71603e708b). T.W.J.G., A.Lo., A.A.C., D.S.S., E.A.C., C.M., J.B., D.M.A., F.C., and M.C.F. were also supported by the EU BiodivERsA scheme (RACE, funded through NERC directed grant NE/G002193/1 and ANR08-Biodiversa-002-03) and NERC (standard grant NE/K012509/1). M.C.F., E.A.C., and C.M. acknowledge the Nouragues Travel Grant Program 2014. R.A.F. was supported by an MIT/Wellcome Trust Fellowship. T.W.J.G. was supported by the People’s Trust for Endangered Species and the Morris Animal Foundation (D12ZO002). J.M.G.S. and M.C.F. were supported by the Leverhulme Trust (RPG-2014-273) and the Morris Animal Foundation (D16ZO-022). F.B. was supported by the ERC (grant ERC 260801–Big_Idea). D.M.A. was funded by Wellcome Trust grant 099202. J.V. was supported by the Hungarian Scientific Research Fund (OTKA K77841) and Bolyai János Research Scholarship, Hungarian Academy of Sciences (BO/00579/14/8). D.J.G. was supported by the Conservation Leadership Programme (grant 0134010) with additional assistance from F. Gebresenbet, R. Kassahun, and S. P. Loader. C.S.-A. was supported by Fondecyt Nº11140902 and 1181758. T.M.D.-B. was supported by the Royal Geographical Society and the Royal Zoological Society of Scotland with assistance from M. Hirschfeld and the Budongo Conservation Field Station. B.W. was supported by the National Research Foundation of Korea (2015R1D1A1A01057282). L.F.T. was supported by FAPESP (#2016/25358-3) and CNPq (#300896/2016-6). L.Be., L.F.S., and R.J.W. were supported by the Australian Research Council (FT100100375, DP120100811). A.A.C. was supported by a Royal Society Wolfson Research Merit award. J.H., A.La., and S.M. were funded by the Swedish Research Council Formas (grant no. 2013- 1389-26445-20). C.W. was funded by the National Research Foundation, South Africa. T.Y.J. and T.S.J. acknowledge NSF grant DEB-1601259. W.E.H. was funded by the NSERC Strategic and Discovery grant programs

Darwin's frogs Rhinoderma darwinii and Rhinoderma rufum are the only known species of amphibians in which males brood their offspring in their vocal sacs. We propose these frogs as flagship species for the conservation of the Austral temperate forests of Chile and Argentina. This recommendation forms part of the vision of the Binational Conservation Strategy for Darwin's Frogs, which was launched in 2018. The strategy is a conservation initiative led by the IUCN SSC Amphibian Specialist Group, which in 2017 convened 30 governmental, non-profit and private organizations from Chile, Argentina and elsewhere. Darwin's frogs are iconic examples of the global amphibian conservation crisis: R. rufum is categorized as Critically Endangered (Possibly Extinct) on the IUCN Red List, and R. darwinii as Endangered. Here we articulate the conservation planning process that led to the development of the conservation strategy for these species and present its main findings and recommendations. Using an evidence-based approach, the Binational Conservation Strategy for Darwin's Frogs contains a comprehensive status review of Rhinoderma spp., including critical threat analyses, and proposes 39 prioritized conservation actions. Its goal is that by 2028, key information gaps on Rhinoderma spp. will be filled, the main threats to these species will be reduced, and financial, legal and societal support will have been achieved. The strategy is a multi-disciplinary, transnational endeavour aimed at ensuring the long-term viability of these unique frogs and their particular habitat. Fil: Azat, Claudio. Universidad Andrés Bello; Chile Fil: Valenzuela Sánchez, Andrés. Universidad Austral de Chile; Chile Fil: Delgado, Soledad. Organización No Gubernamental (ong) Ranita de Darwin; Chile Fil: Cunningham, Andrew A.. The Zoological Society of London; Reino Unido Fil: Alvarado-Rybak, Mario. Universidad Andrés Bello; Chile Fil: Bourke, Johara. Tierärztliche Hochschule Hannover; Alemania Fil: Briones, Raúl. Arauco; Chile Fil: Cabeza, Osvaldo. Zoológico Nacional de Chile; Chile Fil: Castro-Carrasco, Camila. Universidad de Concepción; Chile Fil: Charrier, Andres. Centro Capesuc; Chile Fil: Correa, Claudio. Universidad de Concepción; Chile Fil: Crump, Martha L.. State University of Utah; Estados Unidos Fil: Cuevas, César C.. Universidad Católica de Temuco; Chile Fil: De La Maza, Mariano. Corporación Nacional Forestal Ministerio de Agricultura; Chile Fil: Díaz Vidal, Sandra. División de Recursos Naturales y Biodiversidad; Chile Fil: Flores, Edgardo. Fundación Nahuelbuta Natural; Chile Fil: Harding, Gemma. University Of Kent; Reino Unido Fil: Lavilla, Esteban Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina Fil: Mendez, Marco A.. Universidad de Chile; Chile Fil: Oberwemmer, Frank. Zoo Leipzig; Alemania Fil: Carlos Ortiz, Juan. Universidad de Concepción; Chile Fil: Pastore, Hernán. Administración de Parques Nacionales; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Norte. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede Junín de Los Andes-inibioma-centro de Ecología Aplicada del Neuquén (cean) | Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Instituto de Investigaciones En Biodiversidad y Medioambiente. Subsede Junín de Los Andes-inibioma-centro de Ecología Aplicada del Neuquén (cean).; Argentina Fil: Peñafiel Ricaurte, Alexandra. Universidad Andrés Bello; Chile Fil: Rojas Salinas, Leonora. División de Recursos Naturales y Biodiversidad; Chile Fil: Manuel Serrano, José. Universidad de Chile; Chile Fil: Sepúlveda, Maximiliano A.. Corporación Nacional Forestal Ministerio de Agricultura; Chile Fil: Toledo, Gisela Verónica. Fundación Huilo Huilo; Chile Fil: Úbeda, Carmen A.. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Uribe Rivera, David E.. Organización No Gubernamental (ong) Ranita de Darwin; Chile Fil: Valdivia, Catalina. Universidad Andrés Bello; Chile Fil: Wren, Sally. University Of Otago; Nueva Zelanda Fil: Angulo, Ariadne. Iucn Ssc Amphibian Specialist Group; Canadá

Dispersal is a central process in ecology and evolution. It strongly influences the dynamics of spatially structured populations and affects evolutionary processes by shaping patterns of gene flow. For these reasons, dispersal has received considerable attention from ecologists, evolutionary biologists, and conservationists. Although it has been studied extensively in taxa such as birds and mammals, much less is known about dispersal in vertebrates with complex life cycles such as pond-breeding amphibians. Over the past two decades, researchers have taken an ever-increasing interest in amphibian dispersal and initiated both basic and applied studies, using a broad range of experimental and observational approaches. This body of research reveals complex dispersal patterns, causations, and syndromes, with dramatic consequences for the demography and genetics of amphibian populations. In this review, our goals are to: redefine and clarify the concept of amphibian dispersal; review current knowledge about the effects of individual (i.e., condition-dependent dispersal) and environmental (i.e., context-dependent dispersal) factors during the three stages of dispersal (i.e., emigration, transience, and immigration); identify the demographic and genetic consequences of dispersal in spatially structured amphibian populations; and propose new research avenues to extend our understanding of amphibian dispersal., Hugo Cayuela warmly thanks the Banting Postdoctoral Fellowships program for its financial support. Further-more, Mathieu Denoël is Research Director at Fonds dela Recherche Scientifique—FNRS. During manuscript writing, Andrés Valenzuela-Sánchez was supported bya FONDECYT de postdoctorado No. 3180107. Any useof trade, firm, and product names is for descriptive purposes only and does not imply endorsement by the U.S.Government. Íñigo Martínez-Solano acknowledges funding by FEDER/Ministerio de Ciencia, Innovación y Universidades—Agencia Estatal de Investigación, Spain,grant CGL2017-83131-P.

Emerging fungal diseases represent a threat to food security, animal and human health worldwide. Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. For the first time, Bd was cultured from native and non-native wild amphibians in Chile. Phylogenomic analyses revealed that Chilean isolates AVS2, AVS4 and AVS7 group within the global panzootic lineage of Bd (BdGPL) in a single highly supported clade that includes a genotype previously isolated from the United Kingdom. Our results extend the known distribution of BdGPL in South America and suggest a single and relatively recent introduction of BdGPL into the country, providing additional support to the role of anthropogenic activity in the global spread of this panzootic lineage.

The fungal pathogen Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis and has been a key driver in the catastrophic decline of amphibians globally. While many strategies have been proposed to mitigate Bd outbreaks, few have been successful. In recent years, the use of probiotic formulations that protect an amphibian host by killing or inhibiting Bd have shown promise as an effective chytridiomycosis control strategy. The North American bullfrog (Lithobates catesbeianus) is a common carrier of Bd and harbours a diverse skin microbiota that includes lactic acid bacteria (LAB), a microbial group containing species classified as safe and conferring host benefits. We investigated beneficial/probiotic properties: anti-Bd activity, and adhesion and colonisation characteristics (hydrophobicity, biofilm formation and exopolysaccharide-EPS production) in two confirmed LAB (cLAB-Enterococcus gallinarum CRL 1826, Lactococcus garvieae CRL 1828) and 60 presumptive LAB (pLAB) [together named as LABs] isolated from bullfrog skin.We challenged LABs against eight genetically diverse Bd isolates and found that 32% of the LABs inhibited at least one Bd isolate with varying rates of inhibition. Thus, we established a score of sensitivity from highest (BdGPL AVS7) to lowest (BdGPL C2A) for the studied Bd isolates. We further reveal key factors underlying host adhesion and colonisation of LABs. Specifically, 90.3% of LABs exhibited hydrophilic properties that may promote adhesion to the cutaneous mucus, with the remaining isolates (9.7%) being hydrophobic in nature with a surface polarity compatible with colonisation of acidic, basic or both substrate types. We also found that 59.7% of LABs showed EPS synthesis and 66.1% produced biofilm at different levels: 21% weak, 29% moderate, and 16.1% strong. Together all these properties enhance colonisation of the host surface (mucus or epithelial cells) and may confer protective benefits against Bd through competitive exclusion. Correspondence analysis indicated that biofilm synthesis was LABs specific with high aggregating bacteria correlating with strong biofilm producers, and EPS producers being correlated to negative biofilm producing LABs. We performed Random Amplified Polymorphic DNA (RAPD)-PCR analysis and demonstrated a higher degree of genetic diversity among rod-shaped pLAB than cocci. Based on the LAB genetic analysis and specific probiotic selection criteria that involve beneficial properties, we sequenced 16 pLAB which were identified as Pediococcus pentosaceus, Enterococcus thailandicus, Lactobacillus pentosus/L. plantarum, L. brevis, and L. curvatus. Compatibility assays performed with cLAB and the 16 species described above indicate that all tested LAB can be included in a mixed probiotic formula. Based on our analyses, we suggest that E. gallinarum CRL 1826, L. garvieae CRL 1828, and P. pentosaceus 15 and 18B represent optimal probiotic candidates for Bd control and mitigation., This research was supported by Consejo Nacional de Investigaciones Científicas y Técnicas (PIP 063 to SEP), Consejo de Investigaciones de la Universidad Nacional de Tucumán (PIUNT26/D414 and 26/D645 to SEP, and PIUNT528), Agencia Nacional de Promoción Científica y Tecnológica (PICT2017-2244to SEP, PICT2015-2467to CEA, and PICT2017-4324to MENM), Ministerio de Economía y Competitividad de España (CGL2015-70070-Rto JB), Fondo Nacional de Desarrollo Científico y Tecnológico (1181758toCSA and 3180107 to AVS), Fundacão de Amparo à Pesquisado Estado de São Paulo (2016/25358-3to LFT).

Amphibian chytridiomycosis, due to infection with the fungus Batrachochytrium dendrobatidis (Bd), has been associated with the alarming decline and extinction crisis of amphibians worldwide. It is essential for conservation management to identify regions with high or low suitability for Bd. We use a species distribution model to estimate the environmental suitability of Bd in the Chilean Winter Rainfall - Valdivian Forest biodiversity hotspot. Fourteen environmental variables were used as predictors in the statistical modelling (Maxent, generalized linear models, random forest) which also included 56 independent Bd+ localities. High risk-areas (i.e., suitability above a defined threshold) were validated through prospective field surveys conducted in 2017. As results from Maxent, which only uses presence data, were the only results retained, refugia (i.e., suitability below a defined threshold) were validated with the Bd absences (N = 12) used in the GLM and RF modelling. Our results showed that: (i) suitability for Bd increased with human footprint and with shorter distances to urban centres and water bodies and decreased with elevation; (ii) climate was not a major factor shaping the current distribution of Bd; and (iii) the model predicted high-risk and refugia areas fairly well. Surveys of 24 new localities in high-risk areas confirmed that 23 were Bd+, hence these areas warrant consideration for long-term Bd surveillance, population monitoring and disease mitigation. In addition, five localities with apparent Bd absence were found in the predicted high-risk areas. Our models showed that refugia can exist near high risk areas and Bd+ sites. Four localities with apparent Bd absence were located within the refugia predicted by the model. Preventing Bd transmission to such refugia is of paramount importance for persistence of Bd susceptible amphibian populations. The identification and validation through prospective field surveys of high-risk areas and refugia is imperative to develop strategies to prevent further arrival and establishment of Bd. Also, by identifying amphibian species or populations of conservation concern in such areas, will help to guide specific actions to reduce the biodiversity loss caused by chytridiomycosis.

International audience; Dispersal is a key process in ecology and evolution. Both theoretical and empirical evidence in actively dispersing organisms support the general notion that the use of nearly straight dispersal paths is a highly ef␣cient way to maximize dispersal success in heterogenous landscapes. In homogeneous landscapes, in contrast, the bene␣ts of a straighter dispersal path could be outweighed by an increase in risk costs, favouring the evolution of tortuous dispersal paths resulting in a relatively slow dispersal. Empirical support for this theoretical prediction, however, has remained elusive. To explore this theoretical pre- diction, we studied the movement behaviour of the southern Darwin's frog, Rhinoderma darwinii, a fully terrestrial amphibian inhabiting a highly homogeneous environment (i.e. South American temperate forest). Using spatial captureerecapture data collected over a 4-year period in wild populations, in combination with statistical and simulation modelling, we found evidence of a slow natal dispersal lasting one year or more. In contrast, adults exhibited high site ␣delity, having a median annual displacement of 3.64 m. A correlated random walk model produced synthetic distributions of juvenile annual displacement that were nearly identical to the empirical data, suggesting that a plausible explanation of juvenile dispersal is the use of routine movements (with high path tortuosity) over short temporal scales (

Entanglement of pinnipeds with plastic debris is an emerging conservation and animal welfare issue worldwide. However, the origins and long-term population level consequences of these entanglements are usually unknown. Plastic entanglement could produce a combination of wounds, asphyxiation, or inability to feed that results in the death of a certain percentage of individuals from the total population. In this research, we report on the consequent effect of plastic entanglement on population growth demographics in a South American fur seal (Arctocephalus australis australis) colony on Guafo Island, southern Chile. Using a stochastic matrix population model structured according to age and sex, and assuming an otherwise stable population, we explored population growth rates under five scenarios with differing rates of entanglement: A) a zero rate of plastic entanglement, B) entanglement rates (number of entangled individuals as a proportion of the total number of individuals) as observed in our study population (overall entanglement ratio of 1.2 × 10−3); and for the other scenarios, entanglement ratios as reported in the literature for other pinniped colonies around the world: C) 3.04 × 10−3, D) 4.42 × 10−2, and E) 8.39 × 10−2. Over the 30 years forecasting period and starting with a population size of ∼2950 individuals, the population growth rate was lower under all scenarios with rates of entanglement greater than zero (scenarios B-E). In comparison with scenario A, at the end of the 30-year period forecasted, we calculated a projected decrease in population size of between 20.34% (scenario B) and 91.38% (scenario E). These results suggest that even the lowest levels of entanglement in pinnipeds as reported in the literature might have significant effects over time on population-level dynamics. Our research offers potential insight when devising policy for the management and limitation of plastic pollution in the oceans, and indeed for the conservation and management policy of affected marine species. Furthermore, whilst there are some limitations to our methodology, it offers a straightforward and potentially useful approach for the standardized prediction of impacts at a population level of different rates of plastic pollution and entanglement and could be applied in distinct populations of the same species around the world.

Parasitic chytrid fungi have emerged as a significant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into sterile culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modified a pre-existing protocol for isolating chytrids from infected animals to use toe clips and biopsies from toe webbing rather than euthanizing hosts, and distributed the protocol to interested researchers worldwide as part of the BiodivERsA project RACE – here called the RML protocol. In tandem, we developed a lethal procedure for isolating chytrids from tadpole mouthparts. Reviewing a database of use a decade after their inception, we find that these methods have been widely applied across at least 5 continents, 23 countries and in 62 amphibian species, and have been successfully used to isolate chytrids in remote field locations. Isolation of chytrids by the non-lethal RML protocol occured in 18% of attempts with 207 fungal isolates and three species of chytrid being recovered. Isolation of chytrids from tadpoles occured in 43% of attempts with 334 fungal isolates of one species (Batrachochytrium dendrobatidis) being recovered. Together, these methods have resulted in a significant reduction and refinement of our use of threatened amphibian species and have improved our ability to work with this important group of emerging fungal pathogens.

Amphibians are hosts for a wide variety of micro- and macro-parasites. Chigger mites from the Hannemania genus are known to infect a wide variety of amphibian species across the Americas. In Chile, three species (H. pattoni, H. gonzaleacunae and H. ortizi) have been described infecting native anurans; however, neither impacts nor the microscopic lesions associated with these parasites have been described. Here, we document 70% prevalence of chigger mite infection in Eupsophus roseus and absence of infection in Rhinoderma darwinii in the Nahuelbuta Range, Chile. Additionally, we describe the macroscopic and microscopic lesions produced by H. ortizi in one of these species, documenting previously undescribed lesions (granulomatous myositis) within the host's musculature. These findings highlight that further research to better understand the impacts of chigger mite infection on amphibians is urgently required in Chile and elsewhere.

A link between paternal care and territoriality has been described in several anuran species. The southern Darwin’s frog (Rhinoderma darwinii) has developed a highly specialized form of paternal care known as neomelia, in which males ingest developing embryos and transport them in their vocal sacs until metamorphosis is completed. Based on the main components of territoriality described in amphibians: site fidelity, resource limitation and defence (e.g. of oviposition sites and egg clutches), we hypothesized that R. darwinii males exhibit territoriality. To investigate this, we used a multi-method approach that involved estimating home range and movements, performing social network analyses and monitoring potential egg attendance. Forty-five individual frogs and three egg clutches were monitored in a population from southern Chile between December 2010 and February 2011. Site fidelity was found across all groups (juveniles, females, non-brooding males and brooding males) based on small movements between captures (mean ±1 se; 0.96 ± 0.11 m) and small net displacement (2.95 ± 0.55 m). Home ranges were small (1.82 ± 0.54 m; range: 0.1–16 m 2 ) and did not differ significantly among groups. We did not find evidence of male territoriality, instead male frogs exhibited high home range overlapping and intra-group association. No frogs of either sex were ever seen attending eggs. This evidence supports Wells’ suggestion; territoriality in anuran species with parental care should be expected only if males defend oviposition sites. Conversely, females did not exhibit home range overlapping and showed evidence of very low intra-group association. This study has thrown up a range of additional questions with regard to temporal segregation between non-brooding males, the roles of male and female calls during reproduction, potential female territoriality and what kind of signals triggers egg ingestion by males.

Indexación: Web of Science; Scopus. Climate change is a major threat to biodiversity; the development of models that reliably predict its effects on species distributions is a priority for conservation biogeography. Two of the main issues for accurate temporal predictions from Species Distribution Models (SDM) are model extrapolation and unrealistic dispersal scenarios. We assessed the consequences of these issues on the accuracy of climate-driven SDM predictions for the dispersal-limited Darwin's frog Rhinoderma darwinii in South America. We calibrated models using historical data (1950-1975) and projected them across 40 yr to predict distribution under current climatic conditions, assessing predictive accuracy through the area under the ROC curve (AUC) and True Skill Statistics (TSS), contrasting binary model predictions against temporal-independent validation data set (i.e., current presences/absences). To assess the effects of incorporating dispersal processes we compared the predictive accuracy of dispersal constrained models with no dispersal limited SDMs; and to assess the effects of model extrapolation on the predictive accuracy of SDMs, we compared this between extrapolated and no extrapolated areas. The incorporation of dispersal processes enhanced predictive accuracy, mainly due to a decrease in the false presence rate of model predictions, which is consistent with discrimination of suitable but inaccessible habitat. This also had consequences on range size changes over time, which is the most used proxy for extinction risk from climate change. The area of current climatic conditions that was absent in the baseline conditions (i.e., extrapolated areas) represents 39% of the study area, leading to a significant decrease in predictive accuracy of model predictions for those areas. Our results highlight (1) incorporating dispersal processes can improve predictive accuracy of temporal transference of SDMs and reduce uncertainties of extinction risk assessments from global change; (2) as geographical areas subjected to novel climates are expected to arise, they must be reported as they show less accurate predictions under future climate scenarios. Consequently, environmental extrapolation and dispersal processes should be explicitly incorporated to report and reduce uncertainties in temporal predictions of SDMs, respectively. Doing so, we expect to improve the reliability of the information we provide for conservation decision makers under future climate change scenarios. http://onlinelibrary.wiley.com/doi/10.1002/eap.1556/abstract;jsessionid=1E2084FF99600D0EEC9FA358A3DBC2A3.f02t01

Indexación: Web of Science; Scopus. Background: Body size variation has played a central role in biogeographical research, however, most studies have aimed to describe trends rather than search for underlying mechanisms. In order to provide a more comprehensive understanding of the causes of intra-specific body size variation in ectotherms, we evaluated eight hypotheses proposed in the literature to account for geographical body size variation using the Darwin's frog (Rhinoderma darwinii), an anuran species widely distributed in the temperate forests of South America. Each of the evaluated hypotheses predicted a specific relationship between body size and environmental variables. The level of support for each of these hypotheses was assessed using an information-theoretic approach and based on data from 1015 adult frogs obtained from 14 sites across the entire distributional range of the species. Results: There was strong evidence favouring a single model comprising temperature seasonality as the predictor variable. Larger body sizes were found in areas of greater seasonality, giving support to the "starvation resistance" hypothesis. Considering the known role of temperature on ectothermic metabolism, however, we formulated a new, non-exclusive hypothesis, termed "hibernation hypothesis": greater seasonality is expected to drive larger body size, since metabolic rate is reduced further and longer during colder, longer winters, leading to decreased energy depletion during hibernation, improved survival and increased longevity (and hence growth). Supporting this, a higher post-hibernation body condition in animals from areas of greater seasonality was found. Conclusions: Despite largely recognized effects of temperature on metabolic rate in ectotherms, its importance in determining body size in a gradient of seasonality has been largely overlooked so far. Based on our results, we present and discuss an alternative mechanism, the "hibernation hypothesis", underlying geographical body size variation, which can be helpful to improve our understanding of biogeographical patterns in ectotherms. https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-015-0132-y

The decline of wildlife populations due to emerging infectious disease often shows a common pattern: the parasite invades a naive host population, producing epidemic disease and a population decline, sometimes with extirpation. Some susceptible host populations can survive the epidemic phase and persist with endemic parasitic infection. Understanding host–parasite dynamics leading to persistence of the system is imperative to adequately inform conservation practice. Here we combine field data, statistical and mathematical modelling to explore the dynamics of the apparently stable Rhinoderma darwinii – Batrachochytrium dendrobatidis (Bd) system. Our results indicate that Bd-induced population extirpation may occur even in the absence of epidemics and where parasite prevalence is relatively low. These empirical findings are consistent with previous theoretical predictions showing that highly pathogenic parasites are able to regulate host populations even at extremely low prevalence, highlighting that disease threats should be investigated as a cause of population declines even in the absence of an overt increase in mortality.

Indexación: Web of Science; Scielo. En conservación biológica existe un incremento en los antecedentes de que las enfermedades infecciosas (EIs) pueden afectar especies silvestres causando mortalidades que pueden aumentar el riesgo de extinción. Es así que para conseguir metas en conservación animal hoy se estima necesario conocer el rol de los patógenos en las poblaciones silvestres. En concordancia con lo anterior, los objetivos de este trabajo fueron: 1) determinar la contribución de las EIs a la declinación de las especies amenazadas de la fauna silvestre presente en Chile, de acuerdo a lo señalado por la Lista Roja de la UICN, 2) evaluar la evidencia existente en la literatura científica del impacto de las EIs en estas especies, y 3) proponer el nivel de riesgo para cada especie animal amenazada de Chile de ser impactada por EIs que podrían provocar potenciales declinaciones poblacionales o extinción. En Chile, 105 especies animales se encuentran en alguna categoría de amenaza. En el 16,2 % (N=17) de estas especies se menciona, según la Lista Roja de la UICN, alguna EI como principal amenaza para su conservación. Pese a esto, no existe evidencia en la literatura científica indexada (ISI-wok) de alguna EI provocando declinaciones poblacionales en el país. Se sugiere que los anuros Telmatobius zapahuirensis y T. pefauri, y el cánido Lycalopex fulvipes requieren esfuerzos urgentes de investigación epidemiológica debido a su categoría de conservación y distribución restringida, lo que podría aumentar el riesgo de extinción mediado por EIs. Finalmente, se plantean direcciones futuras en el estudio de las EIs que contribuyan a alcanzar la meta de la conservación biológica en Chile. There is evidence that infectious diseases (IDs) can directly affect wildlife even causing catastrophic died-offs, which increase extinction risk. In this way, to achieve the biological conservation goal we should know the role of IDs on wild populations. The aim of this work was 1) to determine the contribution of IDs in Chilean wildlife declination, according to the IUCN Red List, 2) to evaluate the level of scientific evidence of this threat on wildlife from Chile, and 3) propose a risk level (for each threatened wildlife species) of become threatened by an ID with potential to leading population decline or extinction. In the country, 105 species are in some category of threat, of which 16.2% (N=17) have IDs as potential major threat. Despite this, no evidence is available into scientific literature about an ID producing population declines in Chile. We suggest that anuran species Telmatobius zapahuirensis and T. pefauri, and the canid Lycalopex fulvipes, need urgent efforts in epidemiological research; due in part by its restricted distribution and conservation status, which could increase risk of extinction driven by IDs. By the end, we suggest future directions to enhance the biological conservation in Chile. http://ref.scielo.org/tfbpft

Darwin's frogs (Rhinoderma darwinii and R. rufum) are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd) infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9%) of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans), all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9%) was significantly lower than that found in other anurans (7.3%). The prevalence of infection (30%) in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x(2) = 106.407, P

Darwin's frogs (Rhinoderma darwinii and R. rufum) are two species of mouth-brooding frogs from Chile and Argentina. Here, we present evidence on the extent of declines, current distribution and conservation status of Rhinoderma spp.; including information on abundance, habitat and threats to extant Darwin's frog populations. All known archived Rhinoderma specimens were examined in museums in North America, Europe and South America. Extensive surveys were carried out throughout the historical ranges of R. rufum and R. darwinii from 2008 to 2012. Literature review and location data of 2,244 archived specimens were used to develop historical distribution maps for Rhinoderma spp. Based on records of sightings, optimal linear estimation was used to estimate whether R. rufum can be considered extinct. No extant R. rufum was found and our modelling inferred that this species became extinct in 1982 (95% CI, 1980-2000). Rhinoderma darwinii was found in 36 sites. All populations were within native forest and abundance was highest in Chiloé Island, when compared with Coast, Andes and South populations. Estimated population size and density (five populations) averaged 33.2 frogs/population (range, 10.2-56.3) and 14.9 frogs/100 m(2) (range, 5.3-74.1), respectively. Our results provide further evidence that R. rufum is extinct and indicate that R. darwinii has declined to a much greater degree than previously recognised. Although this species can still be found across a large part of its historical range, remaining populations are small and severely fragmented. Conservation efforts for R. darwinii should be stepped up and the species re-classified as Endangered.