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Hime, Paul M., Alan R. Lemmon, Emily C. Moriarty Lemmon, Elizabeth Prendini, Jeremy M. Brown, Robert C. Thomson, Justin D. Kratovil et al. "Phylogenomics Reveals Ancient Gene Tree Discordance in the Amphibian Tree of Life". Systematic Biology 70, n.º 1 (30 de junio de 2020): 49–66. http://dx.doi.org/10.1093/sysbio/syaa034.
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Abstract Molecular phylogenies have yielded strong support for many parts of the amphibian Tree of Life, but poor support for the resolution of deeper nodes, including relationships among families and orders. To clarify these relationships, we provide a phylogenomic perspective on amphibian relationships by developing a taxon-specific Anchored Hybrid Enrichment protocol targeting hundreds of conserved exons which are effective across the class. After obtaining data from 220 loci for 286 species (representing 94% of the families and 44% of the genera), we estimate a phylogeny for extant amphibians and identify gene tree–species tree conflict across the deepest branches of the amphibian phylogeny. We perform locus-by-locus genealogical interrogation of alternative topological hypotheses for amphibian monophyly, focusing on interordinal relationships. We find that phylogenetic signal deep in the amphibian phylogeny varies greatly across loci in a manner that is consistent with incomplete lineage sorting in the ancestral lineage of extant amphibians. Our results overwhelmingly support amphibian monophyly and a sister relationship between frogs and salamanders, consistent with the Batrachia hypothesis. Species tree analyses converge on a small set of topological hypotheses for the relationships among extant amphibian families. These results clarify several contentious portions of the amphibian Tree of Life, which in conjunction with a set of vetted fossil calibrations, support a surprisingly younger timescale for crown and ordinal amphibian diversification than previously reported. More broadly, our study provides insight into the sources, magnitudes, and heterogeneity of support across loci in phylogenomic data sets.[AIC; Amphibia; Batrachia; Phylogeny; gene tree–species tree discordance; genomics; information theory.]
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deMaynadier, Phillip G. y Malcolm L. Hunter Jr. "The relationship between forest management and amphibian ecology: a review of the North American literature". Environmental Reviews 3, n.º 3-4 (1 de julio de 1995): 230–61. http://dx.doi.org/10.1139/a95-012.
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Questions about the compatibility of forest harvesting practices and conservation of biological diversity are largely driven by concerns that habitat quality for many species may be degraded in intensively managed forest landscapes. We review the literature on relationships between common forest harvesting practices and the distribution and abundance of amphibians, a group that has attracted considerable attention in recent years because of their potential ecological importance in forest ecosystems and because of reports of widespread population declines. Clear-cut harvesting generally has negative short-term impacts on local amphibian populations, especially salamanders. An analysis of the results of 18 studies that examined the effects of clear-cutting on amphibians yielded a 3.5-fold median difference in abundance of amphibians on controls over clear-cuts. However, research on the influence of forest age suggests that the long-term effects of forest harvesting on amphibians are variable, and for many species these effects can be mitigated if regeneration practices leave adequate microhabitat structure intact. In contrast, long-term effects can be significant in forest plantations, which are often associated with intensive site preparations and stand management practices that modify levels of coarse woody debris and other microhabitats. Other forest practices reviewed for their effect on amphibians include prescribed fire, logging roads, and streamside harvesting. We discuss problems commonly encountered in the experimental design and measurement of forest amphibian populations, including a notable lack of pretreatment data, and outline several aspects of amphibian–forestry relationships in need of further research. Management recommendations relevant to conserving upland and riparian zone amphibian habitat during forest harvesting are offered.Key words: amphibians, clear-cutting, coarse woody debris, forest management, logging roads, plantations, prescribed fire, riparian, succession.
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Lips, Karen R. "Overview of chytrid emergence and impacts on amphibians". Philosophical Transactions of the Royal Society B: Biological Sciences 371, n.º 1709 (5 de diciembre de 2016): 20150465. http://dx.doi.org/10.1098/rstb.2015.0465.
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Chytridiomycosis is an emerging infectious disease of amphibians that affects over 700 species on all continents where amphibians occur. The amphibian–chytridiomycosis system is complex, and the response of any amphibian species to chytrid depends on many aspects of the ecology and evolutionary history of the amphibian, the genotype and phenotype of the fungus, and how the biological and physical environment can mediate that interaction. Impacts of chytridiomycosis on amphibians are varied; some species have been driven extinct, populations of others have declined severely, whereas still others have not obviously declined. Understanding patterns and mechanisms of amphibian responses to chytrids is critical for conservation and management. Robust estimates of population numbers are needed to identify species at risk, prioritize taxa for conservation actions, design management strategies for managing populations and species, and to develop effective measures to reduce impacts of chytrids on amphibians. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’.
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Nunes, Ana L., Jennifer M. Fill, Sarah J. Davies, Marike Louw, Alexander D. Rebelo, Corey J. Thorp, Giovanni Vimercati y John Measey. "A global meta-analysis of the ecological impacts of alien species on native amphibians". Proceedings of the Royal Society B: Biological Sciences 286, n.º 1897 (27 de febrero de 2019): 20182528. http://dx.doi.org/10.1098/rspb.2018.2528.
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The exponential increase in species introductions during the Anthropocene has brought about a major loss of biodiversity. Amphibians have suffered large declines, with more than 16% considered to be threatened by invasive species. We conducted a global meta-analysis of the impacts of alien species on native amphibians to determine which aspects of amphibian ecology are most affected by plant, invertebrate, fish, amphibian, reptile, or mammal introductions. Measures of fitness were most strongly affected; amphibian performance was consistently lower in the presence of alien species. While exposure to alien species caused a significant decrease in amphibian behavioural activity when compared with a no species control, this response was stronger towards a control of native impacting species. This indicates a high degree of prey naiveté towards alien species and highlights the importance of using different types of controls in empirical studies. Alien invertebrates had the greatest overall impact on amphibians. This study sets a new agenda for research on biological invasions, highlighting the lack of studies investigating the impacts of alien species on amphibian terrestrial life-history stages. It also emphasizes the strong ecological impacts that alien species have on amphibian fitness and suggests that future introductions or global spread of alien invertebrates could strongly exacerbate current amphibian declines.
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Pranoy Kishore Borah, Avrajjal Ghosh, Bikash Sahoo y Aniruddha Datta-Roy. "A frog that eats foam: predation on the nest of Polypedates sp. (Rhacophoridae) by Euphlyctis sp. (Dicroglossidae)". Journal of Threatened Taxa 12, n.º 14 (26 de octubre de 2020): 17041–44. http://dx.doi.org/10.11609/jott.6291.12.14.17041-17044.
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Amphibians in terms of their predatory behaviour depend mainly upon the ambush technique. Other than predation, amphibians have also been recorded to scavenge to acquire food resources. This is an opportunistic observation of predatory behaviour of an amphibian species (Euphlyctis sp.) on the foam nest of another species (Polypedates sp.). The behaviour was recorded during a routine field sampling, which is broadly written in the body of this write up. Such an observation to our knowledge has not been reported earlier. This observation will have implications in terms of amphibian ecology, behavioural studies, and also diversity studies in the range of foraging behaviour.
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Krishnamurthy, S. V. "Amphibian assemblages in undisturbed and disturbed areas of Kudremukh National Park, central Western Ghats, India". Environmental Conservation 30, n.º 3 (septiembre de 2003): 274–82. http://dx.doi.org/10.1017/s0376892903000274.
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Human activities have fragmented amphibian habitats and affected amphibian diversity and distribution, but the ecology is poorly known. A four-year study assessed the diversity and distribution of amphibians in undisturbed and disturbed sites of the Kudremukh National Park (KNP), India. Iron-ore mining and associated activities in the KNP have induced habitat fragmentation. The disturbed sites had ranges of habitat variables clearly distinguishable from undisturbed sites. Thirty-six species of anurans and six species of caecilians have been recorded in the KNP and the total amphibian species richness represents 20% of the whole Indian amphibian fauna. Among these, 20 species were distributed in both disturbed and undisturbed sites, while 22 were found only in undisturbed sites indicating they may be threatened by further habitat fragmentation. Species diversity and richness formed two distinct groups clearly associated with disturbed and undisturbed habitats, respectively.
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Ramesh, Rasika, Kerry Griffis-Kyle, Gad Perry y Michael Farmer. "Urban Amphibians of the Texas Panhandle". Reptiles & Amphibians 19, n.º 4 (1 de diciembre de 2012): 243–53. http://dx.doi.org/10.17161/randa.v19i4.13918.
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Habitat loss, degradation, and fragmentation due to urbanization are implicated in amphibian declines worldwide. Conservation efforts require information on resident species and their habitat interactions, but amphibian ecology is largely unstudied in urban centers of the Southern High Plains. Here, we gathered baseline data on amphibian presence, species richness, and habitat preferences at site-specific and landscape scales during a severe drought year in the city of Lubbock, in northwestern Texas. Ephemeral playa wetlands are characteristic of this landscape. During urbanization, these have been extensively modifiied for stormwater drainage, agriculture, and construction of roads, buildings and neighborhoods. A semi-arid climate with frequent droughts, together with urbanization, could have an adverse effect on resident amphibians. In 2011, we sampled 23 urban lakes for amphibian presence, using a combination of audio, visual, and larval surveys. We detected five amphibian species at seven lakes; Texas Toads (Anaxyrus speciosus) and Spotted Chorus Frogs (Pseudacris clarkii) were the most frequently encountered species. We found significant negative effects of nearby road density on amphibian species presence and richness. We also detected significant negative effects of basic pH on amphibian species richness. These data can be used for prioritizing lakes for amphibian conservation strategies, to monitor ecosystem function in urban wetlands, and to guide future development and restoration efforts.
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Buckley, Lauren B. y Walter Jetz. "Environmental and historical constraints on global patterns of amphibian richness". Proceedings of the Royal Society B: Biological Sciences 274, n.º 1614 (27 de febrero de 2007): 1167–73. http://dx.doi.org/10.1098/rspb.2006.0436.
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Our knowledge of the broad-scale ecology of vertebrate ectotherms remains very limited. Despite ongoing declines and sensitivity to environmental change, amphibian distributions are particularly poorly understood. We present a global analysis of contemporary environmental and historical constraints on amphibian richness, the first for an ectotherm clade at this scale. Amphibians are presumed to experience environmental constraints distinct from those of better studied endothermic taxa due to their stringent water requirements and the temperature dependence of their energetic costs and performance. Single environmental predictors set upper bounds on, but do not exclusively determine, amphibian richness. Accounting for differing regional histories of speciation and extinction helps resolve triangular or scattered relationships between core environmental predictors and amphibian richness, as the relationships' intercepts or slopes can vary regionally. While the magnitude of richness is strongly determined by regional history, within-region patterns are consistently jointly driven by water and temperature. This confirms that ecophysiological constraints extend to the broad scale. This coupling suggests that shifts in climatic regimes will probably have dramatic consequences for amphibians. Our results illustrate how the environmental and historical explanations of species richness gradients can be reconciled and how the perspectives are complements for understanding broad-scale patterns of diversity.
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Sheridan, Chris D. y Deanna H. Olson. "Amphibian assemblages in zero-order basins in the Oregon Coast Range". Canadian Journal of Forest Research 33, n.º 8 (1 de agosto de 2003): 1452–77. http://dx.doi.org/10.1139/x03-038.
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Zero-order basins, extending from ridgelines to the initiation of first-order streams, were sampled in the Coast Range of Oregon to (i) characterize spatial distribution patterns of amphibian species and assemblages along longitudinal and lateral gradients, and relative to three geomorphic surfaces (valleys, headmost areas, and slopes); and (ii) develop empirical specieshabitat models. Unmanaged zero-order basins were hotspots for amphibian diversity, with significant differences across geomorphic gradients. Captures of riparian-associated amphibians were higher in valley areas, usually within 2 m of basin center. Upland-associated amphibians were captured two times farther from basin centers than riparian-associated species, but highest densities occurred only 25 m from basin center. The most useful empirical models related captures of individual amphibian species to geomorphic, disturbance, moisture, and overstory variables. Ordination and indicator species analysis characterized geomorphic and other environmental gradients in amphibian assemblages and suggested spatial compression of fluvial habitats and riparian-associated species in zero-order basins, in comparison with downstream areas. Our findings have implications for headwater areas managed to hedge risk to and uncertainty in amphibian persistence, namely in the delineation of zones with species management priority, and in the maintenance of natural fluvial and hillslope disturbance regimes, along with the microhabitat features created by these regimes.
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C. Nias, Raymond. "Recent trends in amphibian conservation: a report from the Third World Congress of Herpetology". Pacific Conservation Biology 4, n.º 3 (1998): 179. http://dx.doi.org/10.1071/pc980179.
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The Third World Congress of Herpetology was held in Prague, capital of the Czech Republic from 2nd to 10th August, 1997. Some 40 papers and posters about the conservation of amphibians were presented, including a full day symposium on declining amphibian populations. The Declining Amphibian Task Force (an IUCN Species Survival Commission Specialist Group) held an open meeting on Tuesday, August 5.
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Whitfield, SM, G. Alvarado-Barboza, JG Abarca, H. Zumbado-Ulate, RR Jimenez y J. Kerby. "Ranavirus is widespread in Costa Rica and co-occurs with threatened amphibians". Diseases of Aquatic Organisms 144 (8 de abril de 2021): 89–98. http://dx.doi.org/10.3354/dao03576.
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Amphibians are globally threatened by emerging infectious diseases, and ranaviruses are among the most concerning pathogens to threaten species in the wild. We sampled for ranaviruses in wild amphibians at 8 sites in Costa Rica, spanning broad climatic zones and taxonomic associations. Seven of these sites are inhabited by highly threatened amphibian species that persist at low global population sizes after population declines due to amphibian chytridiomycosis. One of the surveyed sites is occupied by an introduced amphibian species, which is relatively rare in Central America but may be an important pathway for long-distance transport of ranaviruses. We detected ranavirus using quantitative polymerase chain reaction in 16.3% of the 243 individuals and among 5 of our 8 sites, but not at the site with the introduced species. Infection prevalence varied among species and sites, but not with mean annual temperature or mean annual precipitation. Infection intensity did not vary with species, site, temperature, or precipitation. Our results show that ranavirus infection is spatially widespread in Costa Rica, affecting a broad range of host species, and occurs across climatic zones—though we encountered no mortality or morbidity in our sampled species. Ranaviruses are known to cause intermittent mass mortality in amphibian populations, and the threatened species sampled here are likely vulnerable to population impacts from emerging ranaviruses. Therefore, we believe the potential impacts of ranaviruses on amphibian populations in tropical regions have likely been underestimated, and that they should be viewed as a potential major stressor to threatened amphibians in tropical regions.
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Wynne, Felicity J. "Detection of ranavirus in endemic and threatened amphibian populations of the Australian Wet Tropics Region". Pacific Conservation Biology 26, n.º 1 (2020): 93. http://dx.doi.org/10.1071/pc19009.
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The amphibian chytrid fungus (Batrachochytrium dendrobatidis) has driven severe amphibian declines in the Australian tropics. These declines have resulted in species extirpations and extinctions, with many surviving in small, highly threatened populations. Despite the fragility of remaining populations, another group of lethal pathogens, ranaviruses, have rarely been investigated among native amphibians. Ranaviruses have previously been associated with fish, reptile and amphibian mortality events in Australia, yet remain poorly understood here, especially among amphibian hosts. Here, quantitative polymerase chain reaction assays were used to detect ranavirus presence from eight of 17 tested sites containing populations of endangered and critically endangered Australian frog species. Although present in these populations, ranavirus seems to be at the lower bounds of detectability of the assay, which makes firm diagnosis at the individual level unreliable. Repeated (n=14) detections of this pathogen, however, are highly indicative of its presence at each area where it was detected. Therefore, these populations are likely often exposed to ranavirus. The results of this study are not characteristic of populations experiencing rapid disease-associated die-offs or declines, but further investigations should be undertaken to examine the potential drivers of these pathogens to predict future emergence and potential threats to endangered Australian amphibians.
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Gray, MJ, DL Miller y JT Hoverman. "Ecology and pathology of amphibian ranaviruses". Diseases of Aquatic Organisms 87 (3 de diciembre de 2009): 243–66. http://dx.doi.org/10.3354/dao02138.
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Lee, Tracy S., Nicole L. Kahal, Holly L. Kinas, Lea A. Randall, Tyne M. Baker, Vanessa A. Carney, Kris Kendell, Ken Sanderson y Danah Duke. "Advancing Amphibian Conservation through Citizen Science in Urban Municipalities". Diversity 13, n.º 5 (15 de mayo de 2021): 211. http://dx.doi.org/10.3390/d13050211.
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As cities adopt mandates to protect, maintain and restore urban biodiversity, the need for urban ecology studies grows. Species-specific information on the effects of urbanization is often a limiting factor in designing and implementing effective biodiversity strategies. In suburban and exurban areas, amphibians play an important social-ecological role between people and their environment and contribute to ecosystem health. Amphibians are vulnerable to threats and imbalances in the aquatic and terrestrial environment due to a biphasic lifestyle, making them excellent indicators of local environmental health. We developed a citizen science program to systematically monitor amphibians in a large city in Alberta, Canada, where 90% of pre-settlement wetlands have been removed and human activities continue to degrade, alter, and/or fragment remaining amphibian habitats. We demonstrate successes and challenges of using publicly collected data in biodiversity monitoring. Through amphibian monitoring, we show how a citizen science program improved ecological knowledge, engaged the public in urban biodiversity monitoring and improved urban design and planning for biodiversity. We outline lessons learned to inform citizen science program design, including the importance of early engagement of decision makers, quality control assessment, assessing tensions in program design for data and public engagement goals, and incorporating conservation messaging into programming.
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Araújo, Olívia Gabriela dos Santos, Luís Felipe Toledo, Paulo Christiano Anchietta Garcia y Célio Fernando Baptista Haddad. "The amphibians of São Paulo State, Brazil amphibians of São Paulo". Biota Neotropica 9, n.º 4 (diciembre de 2009): 197–209. http://dx.doi.org/10.1590/s1676-06032009000400020.
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The State of São Paulo is one of the most studied regions of Brazil in regard to amphibian species richness and distribution. However, we still do not have a list of species for the State. Therefore, we present here a list including 231 species of amphibians (225 anurans and six caecilians), of which 27 are endemic. We present data about previous and current taxonomists and speculate about future prospects in the study and conservation of amphibian biodiversity in São Paulo State.
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Medina, Daniel, Roberto Ibáñez, Karen R. Lips y Andrew J. Crawford. "Amphibian diversity in Serranía de Majé, an isolated mountain range in eastern Panamá". ZooKeys 859 (2 de julio de 2019): 117–30. http://dx.doi.org/10.3897/zookeys.859.32869.
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Eastern Panamá is within the Mesoamerican biodiversity hotspot and supports an understudied amphibian fauna. Here we characterize the amphibian diversity across an elevational gradient in one of the least studied mountain ranges in eastern Panamá, Serranía de Majé. A total of 38 species were found, which represent 17% of all species reported for Panamá. Based on expected richness function and individual-based rarefaction curves, it is estimated that this is an underestimate and that at least 44 amphibian species occur in this area. Members of all three amphibian orders were encountered, represented by ten families and 22 genera, including five species endemic to Central America. Estimated species richness decreased with elevation, and the mid-elevation site supported both lowland and highland species. Our study provides a baseline for understanding the distribution pattern of amphibians in Panamá, for conservation efforts, and for determining disease-induced changes in amphibian communities.
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Zumbado-Ulate, Héctor, Kiersten N. Nelson, Adrián García-Rodríguez, Gerardo Chaves, Erick Arias, Federico Bolaños, Steven M. Whitfield y Catherine L. Searle. "Endemic Infection of Batrachochytrium dendrobatidis in Costa Rica: Implications for Amphibian Conservation at Regional and Species Level". Diversity 11, n.º 8 (9 de agosto de 2019): 129. http://dx.doi.org/10.3390/d11080129.
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Batrachochytrium dendrobatidis (Bd) has been associated with the severe declines and extinctions of amphibians in Costa Rica that primarily occurred during the 1980s and 1990s. However, the current impact of Bd infection on amphibian species in Costa Rica is unknown. We aimed to update the list of amphibian species in Costa Rica and evaluate the prevalence and infection intensity of Bd infection across the country to aid in the development of effective conservation strategies for amphibians. We reviewed taxonomic lists and included new species descriptions and records for a total of 215 amphibian species in Costa Rica. We also sampled for Bd at nine localities from 2015–2018 and combined these data with additional Bd occurrence data from multiple studies conducted in amphibian communities across Costa Rica from 2005–2018. With this combined dataset, we found that Bd was common (overall infection rate of 23%) across regions and elevations, but infection intensity was below theoretical thresholds associated with mortality. Bd was also more prevalent in Caribbean lowlands and in terrestrial amphibians with an aquatic larval stage; meanwhile, infection load was the highest in direct-developing species (forest and stream-dwellers). Our findings can be used to prioritize regions and taxonomic groups for conservation strategies.
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Ferreira, Rodrigo Barbosa, Alexander Tamanini Mônico, Emanuel Teixeira da Silva, Fernanda Cristina Ferreira Lirio, Cássio Zocca, Marcio Marques Mageski, João Filipe Riva Tonini, Karen H. Beard, Charles Duca y Thiago Silva-Soares. "Amphibians of Santa Teresa, Brazil: the hotspot further evaluated". ZooKeys 857 (25 de junio de 2019): 139–62. http://dx.doi.org/10.3897/zookeys.857.30302.
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A checklist of the amphibians of Santa Teresa municipality, in southeastern Brazil is presented based on fieldwork, examination of specimens in collections, and a literature review. This new amphibian list of Santa Teresa includes 108 species, of which 106 (~98%) belong to Anura and two (~2%) to Gymnophiona. Hylidae was the most represented family with 47 species (43%). Compared to the previous amphibian lists for Santa Teresa, 14 species were added, 17 previously reported species were removed, and 13 species were re-identified based on recent taxonomic rearrangements. Of the 14 species added, 11 (79%) were first recorded during our fieldwork and specimen examination. It is also the first list of caecilians for Santa Teresa. This list suggests that Santa Teresa has 0.16 species per km2 (i.e., 108 species/683 km2), one of the highest densities of amphibian species in the world at a regional scale. This richness represents 78% of the 136 anurans from Espírito Santo state and 10% of the 1,080 amphibians from Brazil. We highlight the need for long-term monitoring to understand population trends and develop effective conservation plans to safeguard this remarkable amphibian richness.
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Lemos-Espinal, Julio A., Geoffrey R. Smith y James C. Rorabaugh. "A conservation checklist of the amphibians and reptiles of Sonora, Mexico, with updated species lists". ZooKeys 829 (11 de marzo de 2019): 131–60. http://dx.doi.org/10.3897/zookeys.829.32146.
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Sonora has a rich natural diversity, including reptiles and amphibians. Sonora’s location on the United States-Mexico border creates some unique conservation challenges for its wildlife. We compiled a list of the amphibian and reptile species currently known for Sonora, summarized the conservation status of these species, and compared our list of species with known species lists for adjacent states. The herpetofauna of Sonora comprises 200 species of amphibians and reptiles (38 amphibians and 162 reptiles). Overall, Sonora shares the most species with Chihuahua, Sinaloa, and Arizona. Approximately 11% of the amphibian and reptile species are IUCN listed, but 35.5% are placed in a protected category by SEMARNAT, and 32.6% are categorized as high risk by the Environmental Vulnerability Score.
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Campos, F. S., G. A. Llorente, L. Rincón, R. Lourenço-de-Moraes y M. Solé. "Protected areas network and conservation efforts concerning threatened amphibians in the Brazilian Atlantic Forest". Web Ecology 16, n.º 1 (1 de febrero de 2016): 9–12. http://dx.doi.org/10.5194/we-16-9-2016.
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Abstract. One of the most common conservation strategies used to preserve threatened species is the establishment of protected areas (PAs), providing a maximum representation of biodiversity with the smallest possible cost. The Brazilian Atlantic Forest is one of the 35 global biodiversity hotspots for conservation priorities, having high rate of habitat loss, which is one of the main factors driving threatened amphibians to extinction. Considering that amphibians are the vertebrate group with the largest number of species geographically excluded from global PAs, gap analysis was employed to evaluate whether or not the PAs of the Brazilian Atlantic Forest safeguard the threatened amphibian species in this region. Species status were compared through the official list of threatened species of the Brazilian Fauna and occurrence maps were obtained from the IUCN (International Union for Conservation of Nature) Red List database. Thirty-eight threatened amphibian species were found, accounting for 17 critically endangered (CR), 10 endangered (EN), and 11 vulnerable (VU). The PAs distributed in the Brazilian Atlantic Forest corresponds to only 9 % of the region's entire area. This protected network covers only 30 % of the total geographical range of the assessed species. Besides, a shift in Brazil's environmental policy has led to PAs downgrading. Therefore, the maintenance of PAs integrity is essential, as well as further investment is necessary for the creation of new reserves, avoiding species loss and reducing the extinction risk of the threatened amphibian species in the Brazilian Atlantic Forest.
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Brown, Donald J., John T. Baccus, D. Bruce Means y Michael R. J. Forstner. "Potential Positive Effects of Fire on Juvenile Amphibians in a Southern USA Pine Forest". Journal of Fish and Wildlife Management 2, n.º 2 (1 de diciembre de 2011): 135–45. http://dx.doi.org/10.3996/062011-jfwm-037.
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Abstract Prescribed fire is a common tool used to conserve and manage the integrity of forest ecosystems. We investigated short-term juvenile amphibian capture and body condition changes subsequent to fire (i.e., one prescribed burn and two wildfires) in a southern United States pine forest. We surveyed amphibians and predatory invertebrates before and after fires occurring during summer 2010. We tested for treatment (i.e., control, wildfire, or prescribed burn) and status (i.e., preburn or postburn) differences in 1) genus-level captures, 2) amphibian health (inferred through a body condition index), and 3) predatory invertebrate captures. Bufo and Scaphiopus captures increased in the prescribed burn treatment; whereas, no differences in Gastrophryne captures were observed. We did not detect a burn status effect on amphibian body condition. Predatory invertebrate captures were higher postburn in the control and wildfire treatments. Neither a low-intensity prescribed burn nor high-intensity wildfires negatively impacted short-term juvenile amphibian captures. Further, we speculate that Bufo and Scaphiopus survivorship may have been higher after the prescribed burn.
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Walston, Leroy J. y Stephen J. Mullin. "Variation in amount of surrounding forest habitat influences the initial orientation of juvenile amphibians emigrating from breeding ponds". Canadian Journal of Zoology 86, n.º 2 (febrero de 2008): 141–46. http://dx.doi.org/10.1139/z07-117.
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Juvenile dispersal is important for the persistence of amphibian populations. Previous studies have observed nonrandom orientation in juvenile amphibians emigrating from breeding ponds; however, the environmental cues associated with these movements are not well understood. We examined the emigration behavior of recently metamorphosed juveniles of three pond-breeding amphibian species from three woodland ponds. We found that juvenile small-mouthed salamanders ( Ambystoma texanum (Matthes, 1855)), American toads ( Bufo americanus Holbrook, 1836), and wood frogs ( Rana sylvatica LeConte, 1825) exhibited nonrandom orientation upon exiting the breeding ponds. Furthermore, we found a positive relationship between captures of juvenile small-mouthed salamanders and wood frogs and width of the surrounding forest habitat, indicating that these species are selecting areas with broader forested habitat upon exiting the breeding ponds. Our results indicate that migrating juvenile amphibians may rely on direct environmental cues because the orientation of small-mouthed salamanders and wood frogs was influenced by width of the surrounding forested habitat. These observations support previous studies suggesting that maintaining forest habitat, along at least a portion of breeding ponds, is important for the persistence of amphibian populations.
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Murrieta-Galindo, Rene, Fabiola López-Barrera, Alberto González-Romero y Gabriela Parra-Olea. "Matrix and habitat quality in a montane cloud-forest landscape: amphibians in coffee plantations in central Veracruz, Mexico". Wildlife Research 40, n.º 1 (2013): 25. http://dx.doi.org/10.1071/wr12076.
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Context The processes of fragmentation, habitat loss, degradation and their combined effects are formidable threats to amphibian populations. Aims We evaluate the effect of three land use-type variables and nine landscape matrix quality factors on amphibian presence in four coffee agro-ecosystems and two cloud-forest fragments in central Veracruz, Mexico. Methods Each site was thoroughly searched using the visual-encounter survey technique along different trails in the most feasible microhabitats for detecting amphibians during four rainy seasons (2005, 2006, 2008 and 2009). Centred on the location where each amphibian species was first recorded, we established what we refer to as a buffer area within a radius of 1.5 km. A Co-Inertia mathematical model was used to determine which of the explanatory variables contributed to maintaining amphibian diversity. The landscape variables were landscape-quality index, open areas, canopy cover (low, intermediate, dense) at the matrix level, river, road and human population density and site size. Local variables were elevation, plant-structure and biological-impact indices. Key results During the study we recorded 1078 amphibians belonging to 26 species, 17 genera and 10 families. The variables explaining the composition of amphibian diversity were river and human population density, low canopy cover at the matrix level, elevation, site size and plant-structure index. Amphibian diversity increased as the structural complexity of the habitat increased, and the former was positively correlated with fragment size. Conclusion The present study indicated that coffee agro-ecosystems and the cloud-forest fragments in the region form a gradient in habitat quality and landscape variables that exert a differential influence on amphibian assemblages, and that each species responds uniquely to different variables. Implications Coffee agro-ecosystems and forest fragments cannot be seen as homogenous patches with a certain habitat quality, separate from the landscape matrix in which they are immersed. Stakeholders are not advised to rely on a single strategy to conserve the amphibian community, but rather should aim to maintain a heterogeneous landscape with forest fragments and coffee agro-ecosystems that have a complex vertical plant structure at the habitat level, especially in highly river-dense landscapes.
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Bovo, Rafael, Carlos Navas, Miguel Tejedo, Saulo Valença y Sidney Gouveia. "Ecophysiology of Amphibians: Information for Best Mechanistic Models". Diversity 10, n.º 4 (26 de octubre de 2018): 118. http://dx.doi.org/10.3390/d10040118.
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Several amphibian lineages epitomize the faunal biodiversity crises, with numerous reports of population declines and extinctions worldwide. Predicting how such lineages will cope with environmental changes is an urgent challenge for biologists. A promising framework for this involves mechanistic modeling, which integrates organismal ecophysiological features and ecological models as a means to establish causal and consequential relationships of species with their physical environment. Solid frameworks built for other tetrapods (e.g., lizards) have proved successful in this context, but its extension to amphibians requires care. First, the natural history of amphibians is distinct within tetrapods, for it includes a biphasic life cycle that undergoes major habitat transitions and changes in sensitivity to environmental factors. Second, the accumulated data on amphibian ecophysiology is not nearly as expressive, is heavily biased towards adult lifeforms of few non-tropical lineages, and overlook the importance of hydrothermal relationships. Thus, we argue that critical usage and improvement in the available data is essential for enhancing the power of mechanistic modeling from the physiological ecology of amphibians. We highlight the complexity of ecophysiological variables and the need for understanding the natural history of the group under study and indicate directions deemed crucial to attaining steady progress in this field.
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Babbitt, Kimberly J., Matthew J. Baber y Tracy L. Tarr. "Patterns of larval amphibian distribution along a wetland hydroperiod gradient". Canadian Journal of Zoology 81, n.º 9 (1 de septiembre de 2003): 1539–52. http://dx.doi.org/10.1139/z03-131.
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We investigated the response of pond-breeding amphibian assemblages to wetland hydroperiod and associated predator changes (invertebrates (abundance and richness) and fish (presence/absence)) in relatively undisturbed landscapes in southern New Hampshire, U.S.A. We sampled 42 wetlands for larval amphibians in 14 spatial blocks (each with a short-, intermediate-, and permanent-hydroperiod wetland) in 1998 and 1999. Assemblages in short-hydroperiod wetlands (<4 months) were depauperate (4 species only) compared with intermediate-hydroperiod (non-permanent but >4 months) and permanent wetlands, which included 7 and 9 species, respectively. Total amphibian abundance did not vary among hydroperiod categories. Species distributions along the hydrological gradient also differed. Rana sylvatica dominated wetlands with short and intermediate hydroperiods, whereas Rana catesbeiana, Bufo americanus, Rana clamitans, and Pseudacris crucifer dominated in those with a longer hydroperiod. Among permanent wetlands, amphibian species richness and abundance did not differ with respect to the presence of predatory fish, although there were species-compositional differences. Amphibian species richness and abundance were positively correlated with the abundance and richness of predatory invertebrates, suggesting that both amphibian and macroinvertebrate predator assemblages may be responding similarly to differences in wetland characteristics (e.g., dissolved oxygen concentration). Overall, our results indicate that wetland hydroperiod has an important influence on amphibian distribution and should be incorporated into regulations and legislation designed to protect biologically diverse isolated wetlands.
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Hirner, Joanna Lynne McGarvie y Sean P. Cox. "Effects of rainbow trout (Oncorhynchus mykiss) on amphibians in productive recreational fishing lakes of British Columbia". Canadian Journal of Fisheries and Aquatic Sciences 64, n.º 12 (1 de diciembre de 2007): 1770–80. http://dx.doi.org/10.1139/f07-139.
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Stocking lakes with trout to enhance recreational fishing can negatively affect native aquatic species. Our objectives were (i) to compare presence, relative abundance, body size, and developmental stage of amphibians in lakes with and without rainbow trout (Oncorhynchus mykiss) in British Columbia’s southern interior, and (ii) to estimate the size of trout impact for application to amphibian conservation. Presence of long-toed salamander (Ambystoma macrodactylum), Columbia spotted frog (Rana luteiventris), and Pacific treefrog (Pseudacris regilla) was not significantly different between lake types. In contrast, western toad (Bufo boreas) larvae presence and relative abundance were significantly higher in lakes with trout. Relative abundance of salamander larvae was significantly lower in lakes with trout, but hypothesis testing did not provide consistent evidence of significantly lower abundances of spotted frog and treefrog larvae. However, estimated ratios of relative abundance (impact) indicated that larvae of the salamander and two frogs were ≥65% less abundant in lakes with trout. Salamander larvae were significantly smaller in lakes with trout. Although amphibians may currently coexist with trout in our study region, trout stocking policy in British Columbia should consider amphibian conservation because the presence of trout is associated with lower amphibian abundance and body size in individual lakes.
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Olker, Jennifer H., Lucinda B. Johnson, Richard P. Axler y Catherine M. Johnson. "Factors influencing ultraviolet radiation dose to developing frogs in northern vernal pools". Canadian Journal of Fisheries and Aquatic Sciences 70, n.º 10 (octubre de 2013): 1531–41. http://dx.doi.org/10.1139/cjfas-2013-0137.
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Ultraviolet-B (UV-B) radiation exposure is one hypothesized mechanism explaining amphibian population declines and malformations, but it is rarely quantified in amphibian habitats. We measured spatial and temporal variations in northern vernal pools with UV-B attenuation through the water column, incident UV-B across pool surfaces and seasons, and cumulative UV-B dose. Atmospheric, local, and landscape effects were compared with variances across spatial and temporal scales, plus influence on exposure risk. Risk was evaluated using published reports on detrimental levels for amphibian survival and health, with life history and behavior of vernal pool breeding Rana sylvatica L. (wood frog). Pools were exposed to sufficiently high UV-B at or near the surface for developing amphibians to be at risk of reduced survival, altered growth, and malformation. Atmospheric conditions, vegetative cover, and water column properties significantly influenced UV-B levels, with oviposition and larval behavior controlling actual embryonic and larval exposure. UV-B risk to vernal pool species is greater than predicted in previous studies. Given changes in light regimes, climate change, and forest harvesting, amphibian UV-B exposure could reach levels of great concern.
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Mohanty, Nitya Prakash y John Measey. "What’s for dinner? Diet and potential trophic impact of an invasive anuran Hoplobatrachus tigerinus on the Andaman archipelago". PeerJ 6 (2 de octubre de 2018): e5698. http://dx.doi.org/10.7717/peerj.5698.
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Amphibian invasions have considerable detrimental impacts on recipient ecosystems. However, reliable risk analysis of invasive amphibians still requires research on more non-native amphibian species. An invasive population of the Indian bullfrog, Hoplobatrachus tigerinus, is currently spreading on the Andaman archipelago and may have significant trophic impacts on native anurans through competition and predation. We carried out diet analyses of the invasive H. tigerinus and native anurans, across four habitat types and two seasons; we hypothesized that (i) small vertebrates constitute a majority of the H. tigerinus diet, particularly by volume and (ii) the diet of H. tigerinus significantly overlaps with the diet of native anurans, thereby, leading to potential competition. We assessed the diet of the invasive H. tigerinus (n = 358), and individuals of the genera Limnonectes (n = 375) and Fejervarya (n = 65) and found a significant dietary overlap of H. tigerinus with only Limnonectes. Small vertebrates, including several endemic species, constituted the majority of H. tigerinus, diet by volume, suggesting potential impact by predation. Prey consumption and electivity of the three anurans indicated a positive relationship between predator-prey body sizes. Individuals of H. tigerinus and Fejervarya chose evasive prey, suggesting that these two taxa are mostly ambush predators; individuals of Limnonectes chose a mixture of sedentary and evasive prey indicating that the species employs a combination of ‘active search’ and ‘sit and wait’ foraging strategies. All three species of anurans mostly consumed terrestrial prey. This intensive study on a genus of newly invasive amphibian contributes to knowledge of the impact of amphibian invasions, and elucidates the feeding ecology of H. tigerinus, and species of the genera Limnonectes and Fejervarya. We also stress the necessity to evaluate prey availability and volume in future studies for meaningful insights into diet of amphibians.
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Dalbeck, Lutz. "A review of the influence of beaver Castor fiber on amphibian assemblages in the floodplains of European temperate streams and rivers". Herpetological Journal, Volume 30, Number 3 (1 de julio de 2020): 135–46. http://dx.doi.org/10.33256/hj30.3.135146.
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Once widespread throughout Eurasia and hunted nearly to extinction, the Eurasian beaver Castor fiber has returned to large parts of its former range, largely through active conservation measures. Beavers can substantially alter small, low order streams and their floodplains through dam construction, burrowing activities and tree felling. Therefore, it is presumed they can significantly influence amphibian distributions, species richness and numbers. We undertook a literature review to compare the available data addressing the effects of beaver dams on amphibians in streams of central temperate and boreal Europe. All 19 amphibian species occurring in the study region were found in beaver ponds, despite their distinctly different habitat requirements. Amphibian species acting as pioneers / early colonisers were under-represented in beaver ponds compared to typical forest species. Open country and ubiquitous species showed intermediate patterns. Beaver ponds in headwater streams often supported the entire spectrum of species occurring in the surrounding landscape, and species numbers in beaver modified headwater streams were comparable to those in floodplains of larger natural rivers. In small headwater streams, beavers tended to be the primary providers of essential habitat for amphibians. In contrast, beaver ponds in the floodplains of larger rivers appeared to have less effect and supported lower average species numbers compared to beaver ponds in headwater streams. We propose that beavers and their habitat creating activities are pivotal determinants of amphibian species richness in the headwater streams, which account for 60–80 % of the water bodies in catchment areas in temperate Europe. By creating habitat for endangered amphibian species, beavers and their ability to modify habitats offer extensive opportunities to implement many aspects of the European Water Framework Directive across the continent and to restore amphibian habitats, contributing to their long-term conservation.
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Shahrudin, Shahriza. "On some additions to the amphibians of Gunung Inas Forest Reserve, Kedah, Peninsular Malaysia". Journal of Threatened Taxa 13, n.º 11 (26 de septiembre de 2021): 19527–39. http://dx.doi.org/10.11609/jott.7072.13.11.19527-19539.
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A survey on amphibian fauna was conducted in compartments 15, 16, and 17 of Gunung Inas Forest Reserve (GIFR), Kedah, Peninsular Malaysia for a period of two-and-a-half years, starting from January 2016 to May 2018, with a total of 20 visits. Observations and collections of amphibian species were carried out in and along the rivers, forest streams, forest pools, rock pools, cascade areas, waterfalls, ditches, temporary pools, forest floors, and forest trails. In total, 41 species of amphibians, belonging to 25 genera, and seven families were collected over the survey period. Of these, 11 species were ranids, followed by 10 dicroglossids, seven rhacophorids, six microhylids, four bufonids, two megophryids, and a single ichthyophiids (Ichthyophis sp.). From these observations, it is being pointed out that 15 species of amphibians represent new records for GIFR, while two species were not detected. This increases the known amphibian diversity of Gunung Inas Forest Reserve from 28 to 41 species.
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Agostini, María G., Pablo E. Saibene, Ignacio Roesler y David Bilenca. "Amphibians of northwestern Buenos Aires province, Argentina: checklist, range extensions and comments on conservation". Check List 12, n.º 6 (19 de noviembre de 2016): 1998. http://dx.doi.org/10.15560/12.6.1998.
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Northwestern Buenos Aires province is located within the Pampas region of Argentina. Agricultural practices have extensively modified native grasslands in a relatively short period, leaving no intact pristine areas. Based on data collected between 2006 and 2015 at 153 ponds in agricultural landscapes, we compiled an annotated list of the amphibians of northwestern Buenos Aires province. We report 13 extant species of amphibians, which represent 43% of the known amphibian diversity in Buenos Aires province, and extend the ranges of three species. Three species found only in herpetological collections extend the list to 16 species. Our study is the first long-term survey of amphibians conducted in this part of Argentina and provides valuable information for future conservation actions across agricultural landscapes.
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Kuzmin, Sergius L. "Threatened amphibians in the former Soviet Union: the current situation and the main threats". Oryx 30, n.º 1 (enero de 1996): 24–30. http://dx.doi.org/10.1017/s0030605300021359.
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Before the dissolution of the USSR in 1991, research and conservation of the region's amphibian fauna was co-ordsinated by a network of scientists. The use of similar survey methods made it possible to obtain comparable estimates of amphibian populations in different parts of the territory. Since 1991 the system of research and conservation has broken down as a result of political changes and economic crisis. The scientific community has become fragmented and there is a scarcity of funds available for essential research and conservation. There is an urgent need for the adoption and implementation of conservation measures, both within the territory of the former USSR and elsewhere, in order to prevent further declines in threatened amphibian populations. This paper presents a summary of the status of amphibians in the former USSR, the threats they face and recommended measures to protect them.
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Kouba, Andrew J. y Carrie K. Vance. "Applied reproductive technologies and genetic resource banking for amphibian conservation". Reproduction, Fertility and Development 21, n.º 6 (2009): 719. http://dx.doi.org/10.1071/rd09038.
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As amphibian populations continue to decline, both government and non-government organisations are establishing captive assurance colonies to secure populations deemed at risk of extinction if left in the wild. For the most part, little is known about the nutritional ecology, reproductive biology or husbandry needs of the animals placed into captive breeding programs. Because of this lack of knowledge, conservation biologists are currently facing the difficult task of maintaining and reproducing these species. Academic and zoo scientists are beginning to examine different technologies for maintaining the genetic diversity of founder populations brought out of the wild before the animals become extinct from rapidly spreading epizootic diseases. One such technology is genetic resource banking and applied reproductive technologies for species that are difficult to reproduce reliably in captivity. Significant advances have been made in the last decade for amphibian assisted reproduction including the use of exogenous hormones for induction of spermiation and ovulation, in vitro fertilisation, short-term cold storage of gametes and long-term cryopreservation of spermatozoa. These scientific breakthroughs for a select few species will no doubt serve as models for future assisted breeding protocols and the increasing number of amphibians requiring conservation intervention. However, the development of specialised assisted breeding protocols that can be applied to many different families of amphibians will likely require species-specific modifications considering their wide range of reproductive modes. The purpose of this review is to summarise the current state of knowledge in the area of assisted reproduction technologies and gene banking for the conservation of amphibians.
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Velo-Antón, Guillermo, David Alvarez y Lucía Alarcón-Ríos. "Monsters in the city: multiple deformities increase in terrestrial-breeding urban salamanders". Amphibia-Reptilia 42, n.º 3 (20 de abril de 2021): 391–98. http://dx.doi.org/10.1163/15685381-bja10057.
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Abstract Amphibians are subjected to an assortment of environmental stressors responsible for their population declines and malformations. Deciphering the underlying causes of amphibian deformities is challenging due to the complex nature and interplay among factors. We evaluated morphological deformities in 9 urban and 9 woodland populations of terrestrial-breeding fire salamanders. We report several types of malformations and higher incidences among urban populations. This model system allowed us to tease apart some of the common factors responsible for amphibian deformations, suggesting airborne/terrestrial pollutants, predation, and/or inbreeding as potential environmental stressors. Yet, the putative underlying factors of fire salamander deformities need to be properly addressed in thorough studies linking habitat quality and the prevalence of morphological abnormalities, as well as predator-prey interactions. Reporting deformation rates among amphibians is key to identify warning signals of population declines and preventing local extinctions.
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Ghirardi, R., J. Cazenave, J. A. López, C. E. Antoniazzi y M. G. Perotti. "Water mould exposure induces enzymatic antioxidant defences in embryos of the Two-colored Oval Frog (Elachistocleis bicolor) (Anura: Microhylidae)". Canadian Journal of Zoology 98, n.º 6 (junio de 2020): 411–16. http://dx.doi.org/10.1139/cjz-2019-0221.
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Water moulds are pathogens of amphibian eggs and embryos. However, little is known about oxidant or antioxidant status of amphibians in response to stress caused by water moulds. We exposed embryo stages of Two-colored Oval Frogs (Elachistocleis bicolor (Guérin-Méneville, 1838)) to a Saprolegnia-like species of water mould to explore homeostatic adjustments by the shifting of oxidative stress markers. We also tested whether water mould infection affected survivorship, hatching time, and morphology of hatching embryos. We found that the Saprolegnia-like species is a genuine stressor and substantially altered the physiological state of E. bicolor embryos. Among antioxidant defences, superoxide dismutase (SOD) and glutathione S-transferase (GST) activities increased in embryos exposed to the Saprolegnia-like species. However, no difference in lipid peroxidation levels was found between treatments, which might indicate that SOD and GST activations could be enough to prevent oxidative damage. Finally, we found higher mortality and number of malformations in the water mould treatment. We showed the stressful effect of water moulds on amphibian embryos, evidenced by the activation of their antioxidant system, and reveal the importance of considering physiological stress markers as key information when studying the potential consequences of disease outbreaks in the ecology and conservation of amphibians.
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Chen, Youhua y Tania Escalante. "Correlates of ecological-niche diversity and extinction risk of amphibians in China under climate change". Australian Systematic Botany 30, n.º 6 (2017): 414. http://dx.doi.org/10.1071/sb17001.
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In the present study, we measured spatiotemporal properties of ecological niches of amphibians in China and tested the relative importance of various niche-diversity metrics for explaining the evolutionary distinctiveness-weighted extinction risk (EDGE) of amphibian species. We applied the hierarchical partitioning technique on the phylogenetically independent contrasts of the niche covariates and EDGE of amphibians, for the purpose of removing the influence of evolutionary inertia among species. As a comparison, phylogenetic least-square general regression (PLGS) was also conducted. The results showed that EDGE was high for those amphibian species of China identified as Critically Endangered or Endangered on the IUCN Red List. Niche fragmentation dimension (NFD) and niche position (NP) were the top two predictors across partial correlation analyses, hierarchical variation partitioning, PLGS and multiple regression analyses. Most temporal niche properties were not significantly associated with the EDGE index of amphibians. Variation partitioning analysis showed that the spatial component of niche measures explained the largest proportion of total variation in EDGE (~31%), whereas the temporal component of niche properties explained ~8% of the variation. The significantly negative role of NFD and extinction risk of amphibians in China may be attributed to a reduced rescue effect, habitat geometry, and local extinction in species with large and continuous distributional ranges.
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BORTEIRO, CLAUDIO, DIEGO BALDO, MAXIMILIANO M. MARONNA, DÉLIO BAÊTA, ARIADNE FARES SABBAG, FRANCISCO KOLENC, CLAUDIO MARTÍNEZ DEBAT et al. "Amphibian parasites of the Order Dermocystida (Ichthyosporea): current knowledge, taxonomic review and new records from Brazil". Zootaxa 4461, n.º 4 (23 de agosto de 2018): 499. http://dx.doi.org/10.11646/zootaxa.4461.4.3.
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Amphibian parasites of the Order Dermocystida (Ichthyosporea) are widespread pathogens known mainly from Europe and North America, which cause primarily a disease of skin and subcutaneous tissue in their hosts. The taxonomy of these organisms has been problematic given their conserved morphology, similar clinical disease and pathology. Currently recognized taxa belong to the three closely related genera, Amphibiocystidium, Amphibiothecum, and Rhinosporidium, whereas species of Dermocystidium and Sphaerothecum destruens include fish parasites. Here, we review the taxonomy of Dermocystida based on a molecular phylogenetic analysis, principally of amphibian parasites, including DNA sequences obtained from amphibian hosts collected in the central-eastern region of South America. A new taxonomic arrangement is proposed, which includes the designation of type material for Dermocystidium pusula, synonymization of Amphibiothecum with Dermocystidium, and the restriction of Amphibiocystidium to its type species A. ranae. We also review the taxonomic status of Dermosporidium hylarum until the present work included in the synonymy of the human and animal pathogen R. seeberi, and considered herein as a valid taxon, however. In addition, a new species of Sphaerothecum parasitic to amphibians is described, being the first record of this genus in the southern hemisphere and in an amphibian host.
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Alford, Ross A. y Stephen J. Richards. "Global Amphibian Declines: A Problem in Applied Ecology". Annual Review of Ecology and Systematics 30, n.º 1 (noviembre de 1999): 133–65. http://dx.doi.org/10.1146/annurev.ecolsys.30.1.133.
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Campos, Felipe S., Ricardo Lourenço-de-Moraes, Gustavo A. Llorente y Mirco Solé. "Cost-effective conservation of amphibian ecology and evolution". Science Advances 3, n.º 6 (junio de 2017): e1602929. http://dx.doi.org/10.1126/sciadv.1602929.
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Rissmann, Melanie, Matthias Lenk, Franziska Stoek, Claudia A. Szentiks, Martin Eiden y Martin H. Groschup. "Replication of Rift Valley Fever Virus in Amphibian and Reptile-Derived Cell Lines". Pathogens 10, n.º 6 (31 de mayo de 2021): 681. http://dx.doi.org/10.3390/pathogens10060681.
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Rift Valley fever phlebovirus (RVFV) is a zoonotic arthropod-borne virus, which has led to devastating epidemics in African countries and on the Arabian Peninsula. Results of in-vivo, in-vitro and field studies suggested that amphibians and reptiles may play a role as reservoir hosts of RVFV, promoting its maintenance during inter-epidemic periods. To elucidate this hypothesis, we examined two newly established reptile-derived cell lines (Egyptian cobra and Chinese pond turtle) and five previously generated reptile- and amphibian-derived cell lines for their replicative capacity for three low- and high-pathogenic RVFV strains. At different time points after infection, viral loads (TCID50), genome loads and the presence of intracellular viral antigen (immunofluorescence) were assessed. Additionally, the influence of temperatures on the replication was examined. Except for one cell line (read-eared slider), all seven cell lines were infected by all three RVFV strains. Two different terrapin-derived cell lines (Common box turtle, Chinese pond turtle) were highly susceptible. A temperature-dependent replication of RVFV was detected for both amphibian and reptile cells. In conclusion, the results of this study indicate the general permissiveness of amphibian and reptile cell lines to RVFV and propose a potential involvement of terrapins in the virus ecology.
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Poyarkov, Nikolay A., Tan Van Nguyen, Evgeniy S. Popov, Peter Geissler, Parinya Pawangkhanant, Thy Neang, Chatmongkon Suwannapoom y Nikolai L. Orlov. "Recent Progress in Taxonomic Studies, Biogeographic Analysis, and Revised Checklist of Amphibians in Indochina". Russian Journal of Herpetology 28, n.º 3A (24 de junio de 2021): 1–110. http://dx.doi.org/10.30906/1026-2296-2021-28-3a-1-110.
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The Indochinese Peninsula is recognized as one of the key global biodiversity hotspots. The amphibian fauna of Indochina (including Vietnam, Laos, Cambodia and Thailand) is one of the richest in the world. About 60% of the known species were described within the last 20 years. We review the literature and our data to assess all recent discoveries and taxonomic changes and compile the first annotated checklist of the amphibian fauna of Indochina since the middle of the 20th century, including updated faunal lists for Vietnam and Thailand. Amphibian checklists for Laos and Cambodia are published for the first time. For each species we provide the following information: scientific name; recommended common name in English; information on type specimens; type locality; data on its distribution within Indochina and beyond; IUCN conservation status; taxonomic comment and the most important references. We review the distribution of each species across the 23 biogeographic subregions of Indochina, estimate the similarity among the regional faunas and evaluate their species richness and endemism. In total we record 423 amphibian species belonging to three orders, 11 families and 71 genera; 199 species (47%) are endemic to Indochina. Comprising 270 known species, the amphibian fauna of Vietnam is the richest (98 endemics, 36.3%), followed by Thailand with 194 species (29 endemics, 14.9%), Laos with 121 species (13 endemics, 10.7%), and Cambodia with 72 species (6 endemics, 8.3%). A cluster analysis of faunal similarity between the subregions shows two major assemblages, divided by the Isthmus of Kra. Within the northern mainland portion of Indochina three clusters can be distinguished: (1) northeastern and northwestern uplands of Vietnam and northern Laos; (2) Northern, Central, and Southern Annamites, the Bolaven Plateau, and central-south Vietnam lowlands; (3) western Indochinese subregions. We identify the Northeast and Northwest Uplands of Vietnam, the Northern, Central and Southern Annamites, the Cardamom Mountains, the mountains of Northeast Thailand, Northern Tenasserim and southern Peninsular Thailand as nine major centers of diversity and endemism of Indochinese amphibians. The analysis of amphibian distribution patterns across Indochina suggests the presence of 14 chorotypes grouped in five major range types. Our results underline the role of Indochina as a key area for amphibian diversity and conservation. Among 423 species of Indochinese amphibians, 152 species (35.9%) were considered as data deficient (DD) or were not evaluated (NE) according to the IUCN Red List criteria; while 76 species (18.0%) were considered vulnerable (VU), endangered (EN) or critically endangered (CR), 20 species (4.7%) were considered to be near threatened (NT), and 175 species (41.4%) to be of the least concern (LC). Our study thus has implications for further conservation efforts on regional and global levels, as well as for understanding the biogeographic patterns of amphibian richness and endemism in Asia.
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Ovalle-Pacheco, Andrés, Claudia Camacho-Rozo y Sandy Arroyo. "Amphibians from Serrania de Las Quinchas, in the mid-Magdalena river valley, Colombia". Check List 15, n.º 3 (17 de mayo de 2019): 387–404. http://dx.doi.org/10.15560/15.3.387.
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We studied the species of amphibians from Serranía de Las Quinchas, in the mid Magdalena Valley region of Colombia, comparing the data from a recent fieldwork with museum records and literature. We present a list of 50 species of amphibians (Anura and Caudata). In our survey, we recorded 36 species, of which 6 represented new records. One of the most interesting record is that of the genus Oedipina, since this is the first time the genus is recorded for the Cordillera Oriental. The number of species is what would be expected in a humid tropical forest of the mid-Magdalena river valley, given the co-occurrence of amphibian faunas distributed in the sub-Andean, Caribbean, and Chocó biogeographic regions.
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Holden, Whitney M., Alexander R. Ebert, Peter F. Canning y Louise A. Rollins-Smith. "Evaluation of Amphotericin B and Chloramphenicol as Alternative Drugs for Treatment of Chytridiomycosis and Their Impacts on Innate Skin Defenses". Applied and Environmental Microbiology 80, n.º 13 (25 de abril de 2014): 4034–41. http://dx.doi.org/10.1128/aem.04171-13.
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ABSTRACTChytridiomycosis, an amphibian skin disease caused by the emerging fungal pathogenBatrachochytrium dendrobatidis, has been implicated in catastrophic global amphibian declines. The result is an alarming decrease in amphibian diversity that is a great concern for the scientific community. Clinical trials testing potential antifungal drugs are needed to identify alternative treatments for amphibians infected with this pathogen. In this study, we quantified the MICs of chloramphenicol (800 μg/ml), amphotericin B (0.8 to 1.6 μg/ml), and itraconazole (Sporanox) (20 ng/ml) againstB. dendrobatidis. Both chloramphenicol and amphotericin B significantly reducedB. dendrobatidisinfection in naturally infected southern leopard frogs (Rana[Lithobates]sphenocephala), although neither drug was capable of complete fungal clearance. Long-term exposure ofR. sphenocephalato these drugs did not inhibit antimicrobial peptide (AMP) synthesis, indicating that neither drug is detrimental to this important innate skin defense. However, we observed that chloramphenicol, but not amphotericin B or itraconazole, inhibited the growth of multipleR. sphenocephalaskin bacterial isolatesin vitroat concentrations below the MIC againstB. dendrobatidis. These results indicate that treatment with chloramphenicol might dramatically alter the protective natural skin microbiome when used as an antifungal agent. This study represents the first examination of the effects of alternative antifungal drug treatments on amphibian innate skin defenses, a crucial step to validating these treatments for practical applications.
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RIVERA-CORREA, MAURICIO, DIEGO BALDO, FLORENCIA VERA CANDIOTI, VICTOR GOYANNES DILL ORRICO, DAVID C. BLACKBURN, SANTIAGO CASTROVIEJO-FISHER, KIN ONN CHAN et al. "Amphibians in Zootaxa: 20 years documenting the global diversity of frogs, salamanders, and caecilians". Zootaxa 4979, n.º 1 (28 de mayo de 2021): 57–69. http://dx.doi.org/10.11646/zootaxa.4979.1.9.
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Zootaxa is a mega-journal that since its inception, 20 years ago, has contributed to the documentation of the planet’s biodiversity. Its role concerning terrestrial vertebrates has been crucial especially for amphibians, which are the most threatened class of vertebrates. As current editors of the Amphibia section, we reviewed the state of knowledge of taxonomic publications on amphibians over the last two decades (from 2001 to 2020). Our review reveals that 2,533 frogs, 259 salamanders, and 55 caecilians have been named in these 20 years, mainly in the tropical regions of South America, Asia, and Africa. More than half (57%) of these species descriptions were published in only 10 journals. At least 827 species of the new amphibians (29% of the total) were described in Zootaxa. This mega-journal has served also as a place of publication for monographs and systematic reviews, in addition to short articles documenting the vocalizations of anurans and the morphology of embryos and larvae. Its efficient evaluation process, the freedom of manuscript length, including full-color figures, and free of cost for the authors, has made Zootaxa a favorite for amphibian researchers. In an era of accelerating rates of biodiversity loss, documenting, describing, naming, and proposing evolutionary scenarios for species is, more than ever, an urgent task.
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Gahl, M. K. y A. J. K. Calhoun. "The role of multiple stressors in ranavirus-caused amphibian mortalities in Acadia National Park wetlands". Canadian Journal of Zoology 88, n.º 1 (enero de 2010): 108–21. http://dx.doi.org/10.1139/z09-124.
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Recent studies suggest that multiple sublethal stressors compromise amphibian immune systems and increase susceptibility to disease. We examined two aspects of multiple stressors and incidence of ranavirus-caused amphibian mortalities in free-living amphibian populations: (1) among-pond differences in physical, chemical, and biological stressors that may exacerbate mortality events, and (2) temporal changes in within-pond stressors that coincide with mortality events. At the among-pond scale, we used principal components analysis and logistic regression followed by Akaike’s information criterion (QAICc) to identify stressors associated with disease incidence. Of the stressors we investigated, aluminum, temperature, and conductivity were most correlated with outbreaks, but it was unclear whether they increased ranavirus-caused mortality events. Sublethal stressors were difficult to isolate in the field and few were significantly associated with ranavirus across all breeding ponds. Our results suggest that each wetland, because of varied physical, biological, and chemical settings, will have its own suite of stressors that sublethally affect amphibians.
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Ruggeri, J., AGS Martins, AHR Domingos, I. Santos, IB Viroomal y LF Toledo. "Seasonal prevalence of the amphibian chytrid in a tropical pond-dwelling tadpole species". Diseases of Aquatic Organisms 142 (17 de diciembre de 2020): 171–76. http://dx.doi.org/10.3354/dao03539.
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Infection by the chytrid fungus Batrachochytrium dendrobatidis (Bd) is a major threat to amphibians and has caused catastrophic global declines of amphibian populations. Some studies have detected a seasonal pattern of infection associated with the local climate, and although most of them have focused on investigating the seasonality of Bd in relation to its impacts on amphibians, fewer have aimed to understand the chytrid persistence in the amphibian assemblage over seasons by investigating reservoir hosts. Since tadpoles are generally tolerant to Bd infection, they often play a relevant role in local disease dynamics. Thus, we hypothesized that tadpoles of Boana faber, a species that can be found in permanent ponds throughout the seasons, would function as Bd reservoirs. We therefore investigated Bd infection prevalence in tadpoles of this species over 2 yr in a nature reserve. As expected, we detected a seasonal variation of Bd infection, with a higher prevalence of Bd during the coldest months (winter) when compared to the warmer months (summer). Interestingly, our seasonal-trend decomposition analysis showed that Bd prevalence is increasing annually in the area, which could represent either a natural fluctuation of this pathogen, or an imminent threat to that anuran assemblage. With this study, we highlight the tadpole of B. faber as a potential reservoir for Bd, and we suggest that monitoring Bd in such hosts could be a powerful tool for identifying priority areas for amphibian conservation.
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Konowalik, Agnieszka, Anna Najbar, Kamil Konowalik, Łukasz Dylewski, Marzena Frydlewicz, Paweł Kisiel, Agata Starzecka, Anna Zaleśna y Krzysztof Kolenda. "Amphibians in an urban environment: a case study from a central European city (Wrocław, Poland)". Urban Ecosystems 23, n.º 2 (30 de noviembre de 2019): 235–43. http://dx.doi.org/10.1007/s11252-019-00912-3.
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AbstractIn 2016, we studied the occurrence of amphibians in 231 selected ponds in the city of Wrocław (Lower Silesia, Poland) and confirmed the occurrence of 10 species: Bombina bombina, Bufo bufo, Bufotes viridis, Hyla arborea, Pelobates fuscus, Pelophylax esculentus complex, Rana arvalis, Rana temporaria, Lissotriton vulgaris and Triturus cristatus. Among all studied sites, the most common were P. esculentus complex (146 occupied sites, 63.2%) and B. bufo (119, 51.5%), while the rarest was P. fuscus (8, 3.5%). The number of species at a single site varied from 0 (28 sites, 12.1%) to 9 (1 site, 0.4%). Frequency and mean amphibian species richness reached 87.9% and 2.7 ± 1.9, respectively. The composition of amphibian species did not change in comparison to previous studies conducted in the years 1997–2009, but declining trends in five species (B. bombina, B. viridis, H. arborea, P. esculentus complex, P. fuscus) were observed (28 compared sites). The results revealed that the permanency of ponds, their occurrence in the vicinity of river valleys, and a high ratio of watercourse length and green area around ponds are positively correlated and have a significant influence on amphibian species richness within the city. Thus, these identified factors should be considered in the course of sustainable urban planning in order to avoid potential conflicts between nature conservation and urban development.
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Alex Smith, M. y David M. Green. "Dispersal and the metapopulation paradigm in amphibian ecology and conservation: are all amphibian populations metapopulations?" Ecography 28, n.º 1 (febrero de 2005): 110–28. http://dx.doi.org/10.1111/j.0906-7590.2005.04042.x.
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Lastra González, D., V. Baláž, P. Chajma y J. Vojar. "Surveying for Batrachochytrium salamandrivorans presence in Spanish captive collections of amphibians". Diseases of Aquatic Organisms 142 (3 de diciembre de 2020): 99–103. http://dx.doi.org/10.3354/dao03535.
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Batrachochytrium salamandrivorans (Bsal), a pathogenic fungus causing the fatal disease chytridiomycosis in amphibians, was likely introduced to Europe through the trade in pet salamanders from Asia and then escaped into wild populations. Among European countries, Spain has a large number of private breeders and keepers of pet salamanders, and cases of Bsal in wild and captive populations already have been confirmed there. However, surveillance for the pathogen in Spanish collections of amphibians is sparse. Therefore, assisted by private owners and breeders, we surveyed 10 amphibian collections and analysed a total of 317 samples for presence of Bsal. All of our analyses yielded negative results. However, this apparent lack of Bsal cases in captivity should not encourage relaxation of vigilance, quarantine efforts or good practices. Because amphibian collections represent highly dynamic environments (animals are coming in and out), the pathogen could easily be introduced into a collection by new individuals. Any case of Bsal infection in captive animals could lead to its further spread to wild populations of susceptible species, potentially decimating them, and thus should be prevented.
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Jo, T., S. Tomita, Y. Kohmatsu, M. Osathanunkul, A. Ushimaru y T. Minamoto. "Seasonal monitoring of Hida salamander Hynobius kimurae using environmental DNA with a genus-specific primer set". Endangered Species Research 43 (19 de noviembre de 2020): 341–52. http://dx.doi.org/10.3354/esr01073.
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The diversity and the abundance of amphibians have dramatically declined globally over the past 30 years, and the monitoring and conservation of their habitats is essential. However, traditional methods such as bait trapping and mark-recapture are costly, and morphological identification usually requires a high level of taxonomic expertise. Here, seasonal surveillances of Hida salamander Hynobius kimurae were performed by means of environmental DNA (eDNA) analysis with Hynobius-specific primers and a species-specific TaqMan probe. Water sampling and visual surveys were conducted seasonally in a stream in Kyoto Prefecture, Japan. Detection rates of eDNA were then calculated by real-time PCR, and eDNA site occupancy probability was estimated by multi-scale occupancy modeling. The eDNA-based detection rate of Hida salamander was 76.7%, whereas the visual survey-based detection rate was 23.3%, and target eDNA was detected at almost all sites where the presence of target species was visually confirmed. Moreover, factors relating to the site- and sample-level occurrence probabilities of the target eDNA differed depending on the developmental stage of the target species. Our findings support previous studies showing that eDNA analysis enables an effective assessment of amphibian distributions without damaging the organisms or their habitat, and we compare for the first time the site occupancy probability of amphibian eDNA throughout the life cycle of an amphibian species. The present study contributes to the development of eDNA analysis as a tool for understanding the distribution and seasonal activity of amphibian species and will thus aid in the planning of conservation measures and habitat restoration for these species.