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Chew A, West M, Berger L, Brannelly LA. The impacts of water quality on the amphibian chytrid fungal pathogen: A systematic review. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13274. [PMID: 38775382 PMCID: PMC11110485 DOI: 10.1111/1758-2229.13274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 04/06/2024] [Indexed: 05/25/2024]
Abstract
The pathogenic fungus Batrachochytrium dendrobatidis has caused declines of amphibians worldwide. Yet our understanding of how water quality influences fungal pathogenicity is limited. Here, we reviewed experimental studies on the effect of water quality on this pathogen to determine which parameters impacted disease dynamics consistently. The strongest evidence for protective effects is salinity which shows strong antifungal properties in hosts at natural levels. Although many fungicides had detrimental effects on the fungal pathogen in vitro, their impact on the host is variable and they can worsen infection outcomes. However, one fungicide, epoxiconazole, reduced disease effects experimentally and likely in the field. While heavy metals are frequently studied, there is weak evidence that they influence infection outcomes. Nitrogen and phosphorous do not appear to impact pathogen growth or infection in the amphibian host. The effects of other chemicals, like pesticides and disinfectants on infection were mostly unclear with mixed results or lacking an in vivo component. Our study shows that water chemistry does impact disease dynamics, but the effects of specific parameters require more investigation. Improving our understanding of how water chemistry influences disease dynamics will help predict the impact of chytridiomycosis, especially in amphibian populations affected by land use changes.
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Affiliation(s)
- Adeline Chew
- School of BiosciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Matt West
- School of BiosciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Lee Berger
- Melbourne Veterinary SchoolThe University of MelbourneWerribeeVictoriaAustralia
| | - Laura A. Brannelly
- Melbourne Veterinary SchoolThe University of MelbourneWerribeeVictoriaAustralia
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2
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Edwards AW, Harrison XA, Smith MA, Chavarría Díaz MM, Sasa M, Janzen DH, Hallwachs W, Chaves G, Fernández R, Palmer C, Wilson C, North A, Puschendorf R. Amphibian diversity across three adjacent ecosystems in Área de Conservación Guanacaste, Costa Rica. PeerJ 2023; 11:e16185. [PMID: 38034867 PMCID: PMC10688307 DOI: 10.7717/peerj.16185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 09/05/2023] [Indexed: 12/02/2023] Open
Abstract
Amphibians are the most threatened species-rich vertebrate group, with species extinctions and population declines occurring globally, even in protected and seemingly pristine habitats. These 'enigmatic declines' are generated by climate change and infectious diseases. However, the consequences of these declines are undocumented as no baseline ecological data exists for most affected areas. Like other neotropical countries, Costa Rica, including Área de Conservación Guanacaste (ACG) in north-western Costa Rica, experienced rapid amphibian population declines and apparent extinctions during the past three decades. To delineate amphibian diversity patterns within ACG, a large-scale comparison of multiple sites and habitats was conducted. Distance and time constrained visual encounter surveys characterised species richness at five sites-Murciélago (dry forest), Santa Rosa (dry forest), Maritza (mid-elevation dry-rain forest intersect), San Gerardo (rainforest) and Cacao (cloud forest). Furthermore, species-richness patterns for Cacao were compared with historic data from 1987-8, before amphibians declined in the area. Rainforests had the highest species richness, with triple the species of their dry forest counterparts. A decline of 45% (20 to 11 species) in amphibian species richness was encountered when comparing historic and contemporary data for Cacao. Conservation efforts sometimes focus on increasing the resilience of protected areas, by increasing their range of ecosystems. In this sense ACG is unique containing many tropical ecosystems compressed in a small geographic space, all protected and recognised as a UNESCO world heritage site. It thus provides an extraordinary platform to understand changes, past and present, and the resilience of tropical ecosystems and assemblages, or lack thereof, to climate change.
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Affiliation(s)
- Alex W. Edwards
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, Devon, UK
| | - Xavier A. Harrison
- Centre for Ecology & Conservation, University of Exeter, Penryn, Cornwall, UK
| | - M. Alex Smith
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | | | - Mahmood Sasa
- School of Biology, Universidad de Costa Rica, San Pedro, San Jose, Costa Rica
| | - Daniel H. Janzen
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Winnie Hallwachs
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Gerardo Chaves
- School of Biology, Universidad de Costa Rica, San Pedro, San Jose, Costa Rica
| | - Roberto Fernández
- Guanacaste Dry Forest Conservation Fund, Philadelphia, United States of America
| | - Caroline Palmer
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, Devon, UK
| | - Chloe Wilson
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, Devon, UK
| | - Alexandra North
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, Devon, UK
| | - Robert Puschendorf
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, Devon, UK
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3
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Scheele BC, Heard GW, Cardillo M, Duncan RP, Gillespie GR, Hoskin CJ, Mahony M, Newell D, Rowley JJL, Sopniewski J. An invasive pathogen drives directional niche contractions in amphibians. Nat Ecol Evol 2023; 7:1682-1692. [PMID: 37550511 DOI: 10.1038/s41559-023-02155-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 07/07/2023] [Indexed: 08/09/2023]
Abstract
Global change is causing an unprecedented restructuring of ecosystems, with the spread of invasive species being a key driver. While population declines of native species due to invasives are well documented, much less is known about whether new biotic interactions reshape niches of native species. Here we quantify geographic range and realized-niche contractions in Australian frog species following the introduction of amphibian chytrid fungus Batrachochytrium dendrobatidis, a pathogen responsible for catastrophic amphibian declines worldwide. We show that chytrid-impacted species experienced proportionately greater contractions in niche breadth than geographic distribution following chytrid emergence. Furthermore, niche contractions were directional, with contemporary distributions of chytrid-impacted species characterized by higher temperatures, lower diurnal temperature range, higher precipitation and lower elevations. Areas with these conditions may enable host persistence with chytrid through lower pathogenicity of the fungus and/or greater demographic resilience. Nevertheless, contraction to a narrower subset of environmental conditions could increase host vulnerability to other threatening processes and should be considered in assessments of extinction risk and during conservation planning. More broadly, our results emphasize that biotic interactions can strongly shape species realized niches and that large-scale niche contractions due to new species interactions-particularly emerging pathogens-could be widespread.
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Affiliation(s)
- Ben C Scheele
- Fenner School of Environment and Society, Australian National University, Canberra, Australian Capital Territory, Australia.
- Macroevolution and Macroecology Group, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia.
| | - Geoffrey W Heard
- Terrestrial Ecosystem Research Network and Centre for Biodiversity and Conservation Science, University of Queensland, Brisbane, Queensland, Australia
| | - Marcel Cardillo
- Macroevolution and Macroecology Group, Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Richard P Duncan
- Centre for Conservation Ecology and Genomics, University of Canberra, Canberra, Australian Capital Territory, Australia
| | - Graeme R Gillespie
- Science, Economics and Insights Division, Department of Planning and Environment, Parramatta, New South Wales, Australia
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Conrad J Hoskin
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | - Michael Mahony
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales, Australia
| | - David Newell
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia
| | - Jodi J L Rowley
- Australian Museum Research Institute, Australian Museum, Sydney, New South Wales, Australia
- Centre for Ecosystem Science; School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Jarrod Sopniewski
- Fenner School of Environment and Society, Australian National University, Canberra, Australian Capital Territory, Australia
- School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
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4
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Mata-Guel EO, Soh MCK, Butler CW, Morris RJ, Razgour O, Peh KSH. Impacts of anthropogenic climate change on tropical montane forests: an appraisal of the evidence. Biol Rev Camb Philos Soc 2023; 98:1200-1224. [PMID: 36990691 DOI: 10.1111/brv.12950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/31/2023]
Abstract
In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects. Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.
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Affiliation(s)
- Erik O Mata-Guel
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Malcolm C K Soh
- National Park Boards, 1 Cluny Road, Singapore, 259569, Singapore
| | - Connor W Butler
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Rebecca J Morris
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Orly Razgour
- Biosciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Kelvin S-H Peh
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
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5
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Tytar V, Nekrasova O, Pupins M, Skute A, Kirjušina M, Gravele E, Mezaraupe L, Marushchak O, Čeirāns A, Kozynenko I, Kulikova AA. Modeling the Distribution of the Chytrid Fungus Batrachochytrium dendrobatidis with Special Reference to Ukraine. J Fungi (Basel) 2023; 9:607. [PMID: 37367543 DOI: 10.3390/jof9060607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/21/2023] [Accepted: 05/22/2023] [Indexed: 06/28/2023] Open
Abstract
Amphibians are the most threatened group of vertebrates. While habitat loss poses the greatest threat to amphibians, a spreading fungal disease caused by Batrachochytrium dendrobatidis Longcore, Pessier & D.K. Nichols 1999 (Bd) is seriously affecting an increasing number of species. Although Bd is widely prevalent, there are identifiable heterogeneities in the pathogen's distribution that are linked to environmental parameters. Our objective was to identify conditions that affect the geographic distribution of this pathogen using species distribution models (SDMs) with a special focus on Eastern Europe. SDMs can help identify hotspots for future outbreaks of Bd but perhaps more importantly identify locations that may be environmental refuges ("coldspots") from infection. In general, climate is considered a major factor driving amphibian disease dynamics, but temperature in particular has received increased attention. Here, 42 environmental raster layers containing data on climate, soil, and human impact were used. The mean annual temperature range (or 'continentality') was found to have the strongest constraint on the geographic distribution of this pathogen. The modeling allowed to distinguish presumable locations that may be environmental refuges from infection and set up a framework to guide future search (sampling) of chytridiomycosis in Eastern Europe.
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Affiliation(s)
- Volodymyr Tytar
- I.I. Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, 01030 Kyiv, Ukraine
| | - Oksana Nekrasova
- I.I. Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, 01030 Kyiv, Ukraine
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Mihails Pupins
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Arturs Skute
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Muza Kirjušina
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Evita Gravele
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Ligita Mezaraupe
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Oleksii Marushchak
- I.I. Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, 01030 Kyiv, Ukraine
| | - Andris Čeirāns
- Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils University, LV5400 Daugavpils, Latvia
| | - Iryna Kozynenko
- I.I. Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, 01030 Kyiv, Ukraine
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6
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Lambertini C, Ernetti JR, Missassi AFR, Jorge RF, da Silva Leite D, Lima AP, Toledo LF. Chytrid fungus in amphibians from the lowland Brazilian Amazon. DISEASES OF AQUATIC ORGANISMS 2022; 152:115-125. [PMID: 36519683 DOI: 10.3354/dao03709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Infectious diseases are one of the main threats to biodiversity. The fungus Batrachochytrium dendrobatidis (Bd) is associated with several amphibian losses around the globe, and environmental conditions may dictate the success of pathogen spread. The Brazilian Amazon has been considered climatically unsuitable for chytrid fungus, but additional information on Bd dynamics in this ecoregion is still lacking. We sampled 462 amphibians (449 anurans, 4 caudatans and 9 caecilians), representing 57 species from the Brazilian Amazon, and quantified Bd infections using qPCR. We tested whether abiotic variables predicted the risk of Bd infections, and tested for relationships between biotic variables and Bd. Finally, we experimentally tested the effects of Bd strains CLFT 156 and CLFT 102 (from the southern and northern Atlantic Forest, respectively) on Atelopus manauensis. We detected higher Bd prevalence than those previously reported for the Brazilian Amazon, and positive individuals in all 3 orders of amphibians sampled. Both biotic and abiotic predictors were related to prevalence, and no variable explained infection load. Moreover, we detected higher Bd prevalence in forested than open areas, while the host's reproductive biology was not a factor. We detected higher mortality in the experimental group infected with CLFT 156, probably because this strain was isolated from a region characterized by discrepant climatic conditions (latitudinally more distant) when compared with the host's sampling site in Amazon. The lowland Brazilian Amazon is still underexplored and future studies targeting all amphibian orders are essential to better understand Bd infection dynamics in this region.
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Affiliation(s)
- Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo 13083-862, Brazil
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7
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Nie P, Feng J. Global niche and range shifts of Batrachochytrium dendrobatidis, a highly virulent amphibian-killing fungus. Fungal Biol 2022; 126:809-816. [PMID: 36517148 DOI: 10.1016/j.funbio.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/05/2022] [Accepted: 10/18/2022] [Indexed: 01/07/2023]
Abstract
Batrachochytrium dendrobatidis (Bd) is one of the world's most invasive species, and is responsible for chytridiomycosis, an emerging infectious disease that has caused huge losses of global amphibian biodiversity. Few studies have investigated invasive Bd's niche and range relative to those of native Bd. In the present study, we applied niche and range dynamic models to investigate global niche and range dynamics between native and invasive Bd. Invasive Bd occupied wider and different niche positions than did native Bd. Additionally, invasive Bd was observed in hotter, colder, wetter, drier, and more labile climatic conditions. Contrast to most relevant studies presuming Bd's niche remaining stable, we found that invasive Bd rejected niche conservatism hypotheses, suggesting its high lability in niche, and huge invasion potential. Bd's niche non-conservatism may result in range lability, and small niche expansions could induce large increases in range. Niche shifts may therefore be a more sensitive indicator of invasion than are range shifts. Our findings indicate that Bd is a high-risk invasive fungus not only due to its high infection and mortality rates, but also due to its high niche and range lability, which enhance its ability to adapt to novel climatic conditions. Therefore, invasive Bd should be a high-priority focus species in strategizing against biological invasions.
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Affiliation(s)
- Peixiao Nie
- Department of Life Science and Agronomy, Dali University, Dali, 671003, China
| | - Jianmeng Feng
- Department of Life Science and Agronomy, Dali University, Dali, 671003, China.
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8
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Zumbado-Ulate H, Neam K, García-Rodríguez A, Ochoa-Ochoa L, Chaves G, Kolby JE, Granados-Martínez S, Hertz A, Bolaños F, Ariano-Sánchez D, Puschendorf R, Searle CL. Ecological correlates of extinction risk and persistence of direct-developing stream-dwelling frogs in Mesoamerica. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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9
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Moubarak M, Fischhoff IR, Han BA, Castellanos AA. A spatially explicit risk assessment of salamander populations to
Batrachochytrium salamandrivorans
in the United States. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | | | - Barbara A. Han
- Cary Institute of Ecosystem Studies Millbrook New York USA
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10
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Habitat fragmentation in the Brazilian Atlantic Forest is associated with erosion of frog immunogenetic diversity and increased fungal infections. Immunogenetics 2022; 74:431-441. [PMID: 35080658 DOI: 10.1007/s00251-022-01252-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/12/2022] [Indexed: 11/05/2022]
Abstract
Habitat fragmentation and infectious diseases threaten wildlife globally, but the interactions of these threats are poorly understood. For instance, while habitat fragmentation can impact genetic diversity at neutral loci, the impacts on disease-relevant loci are less well-studied. We examined the effects of habitat fragmentation in Brazil's Atlantic Forest on amphibian genetic diversity at an immune locus related to antigen presentation and detection (MHC IIB Exon 2). We used a custom high-throughput assay to sequence a fragment of MHC IIB and quantified Batrachochytrium dendrobatidis (Bd) infections in six frog species in two Atlantic Forest regions. Habitat fragmentation was associated with genetic erosion at MHC IIB Exon 2. This erosion was most severe in forest specialists. Significant Bd infections were detected only in one Atlantic Forest region, potentially due to relatively higher elevation. In this region, forest specialists showed an increase in both Bd prevalence and infection loads in fragmented habitats. Reduced population-level MHC IIB diversity was associated with increased Bd infection risk. On the individual level, MHC IIB heterozygotes exhibited a trend toward reduced Bd infection risk, although this was marginally non-significant. Our results suggest that habitat fragmentation increases Bd infection susceptibility in amphibians, mediated at least in part through erosion of immunogenetic diversity. Our findings have implications for management of fragmented populations in the face of emerging infectious diseases.
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11
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Alvarado-Rybak M, Lepe-Lopez M, Peñafiel-Ricaurte A, Valenzuela-Sánchez A, Valdivia C, Mardones FO, Bacigalupe LD, Puschendorf R, Cunningham AA, Azat C. Bioclimatic and anthropogenic variables shape the occurrence of Batrachochytrium dendrobatidis over a large latitudinal gradient. Sci Rep 2021; 11:17383. [PMID: 34462470 PMCID: PMC8405646 DOI: 10.1038/s41598-021-96535-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 08/05/2021] [Indexed: 02/07/2023] Open
Abstract
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.
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Affiliation(s)
- Mario Alvarado-Rybak
- Sustainability Research Centre & PhD Programme in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Republica 252, Santiago, Chile
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
- Núcleo de Ciencias Aplicadas en Ciencias Veterinarias y Agronómicas, Universidad de las Américas, Echaurren 140, Santiago, Chile
| | - Manuel Lepe-Lopez
- Sustainability Research Centre & PhD Programme in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Republica 252, Santiago, Chile
| | - Alexandra Peñafiel-Ricaurte
- Sustainability Research Centre & PhD Programme in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Republica 252, Santiago, Chile
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Andrés Valenzuela-Sánchez
- Sustainability Research Centre & PhD Programme in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Republica 252, Santiago, Chile
- ONG Ranita de Darwin, Nataniel Cox 152, Santiago, Chile
- Instituto de Conservación, Biodiversidad y Territorio, Facultad de Ciencias Forestales y Recursos Naturales, Universidad Austral de Chile, 5110566, Valdivia, Chile
| | - Catalina Valdivia
- Sustainability Research Centre & PhD Programme in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Republica 252, Santiago, Chile
| | - Fernando O Mardones
- Escuela de Medicina Veterinaria, Facultad de Agronomía e Ingeniería Forestal, Facultad de Ciencias Biológicas y Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Leonardo D Bacigalupe
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Robert Puschendorf
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
| | - Andrew A Cunningham
- Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK
| | - Claudio Azat
- Sustainability Research Centre & PhD Programme in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Republica 252, Santiago, Chile.
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12
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Olson DH, Ronnenberg KL, Glidden CK, Christiansen KR, Blaustein AR. Global Patterns of the Fungal Pathogen Batrachochytrium dendrobatidis Support Conservation Urgency. Front Vet Sci 2021; 8:685877. [PMID: 34336978 PMCID: PMC8322974 DOI: 10.3389/fvets.2021.685877] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 06/15/2021] [Indexed: 12/21/2022] Open
Abstract
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a skin pathogen that can cause the emerging infectious disease chytridiomycosis in susceptible species. It has been considered one of the most severe threats to amphibian biodiversity. We aimed to provide an updated compilation of global Bd occurrences by host taxon and geography, and with the larger global Bd dataset we reanalyzed Bd associations with environmental metrics at the world and regional scales. We also compared our Bd data compilation with a recent independent assessment to provide a more comprehensive count of species and countries with Bd occurrences. Bd has been detected in 1,375 of 2,525 (55%) species sampled, more than doubling known species infections since 2013. Bd occurrence is known from 93 of 134 (69%) countries at this writing; this compares to known occurrences in 56 of 82 (68%) countries in 2013. Climate-niche space is highly associated with Bd detection, with different climate metrics emerging as key predictors of Bd occurrence at regional scales; this warrants further assessment relative to climate-change projections. The accretion of Bd occurrence reports points to the common aims of worldwide investigators to understand the conservation concerns for amphibian biodiversity in the face of potential disease threat. Renewed calls for better mitigation of amphibian disease threats resonate across continents with amphibians, especially outside Asia. As Bd appears to be able to infect about half of amphibian taxa and sites, there is considerable room for biosecurity actions to forestall its spread using both bottom-up community-run efforts and top-down national-to-international policies. Conservation safeguards for sensitive species and biodiversity refugia are continuing priorities.
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Affiliation(s)
- Deanna H Olson
- Pacific Northwest Research Station, United States Department of Agriculture (USDA) Forest Service, Corvallis, OR, United States
| | - Kathryn L Ronnenberg
- Pacific Northwest Research Station, United States Department of Agriculture (USDA) Forest Service, Corvallis, OR, United States
| | | | - Kelly R Christiansen
- Pacific Northwest Research Station, United States Department of Agriculture (USDA) Forest Service, Corvallis, OR, United States
| | - Andrew R Blaustein
- Department of Integrative Biology, Oregon State University, Corvallis, OR, United States
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13
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Beukema W, Erens J, Schulz V, Stegen G, Spitzen-van der Sluijs A, Stark T, Laudelout A, Kinet T, Kirschey T, Poulain M, Miaud C, Steinfartz S, Martel A, Pasmans F. Landscape epidemiology of Batrachochytrium salamandrivorans: reconciling data limitations and conservation urgency. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02342. [PMID: 33817953 DOI: 10.1002/eap.2342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 12/01/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Starting in 2010, rapid fire salamander (Salamandra salamandra) population declines in northwestern Europe heralded the emergence of Batrachochytrium salamandrivorans (Bsal), a salamander-pathogenic chytrid fungus. Bsal poses an imminent threat to global salamander diversity owing to its wide host range, high pathogenicity, and long-term persistence in ecosystems. While there is a pressing need to develop further research and conservation actions, data limitations inherent to recent pathogen emergence obscure necessary insights into Bsal disease ecology. Here, we use a hierarchical modeling framework to describe Bsal landscape epidemiology of outbreak sites in light of these methodological challenges. Using model selection and machine learning, we find that Bsal presence is associated with humid and relatively cool, stable climates. Outbreaks are generally located in areas characterized by low landscape heterogeneity and low steepness of slope. We further find an association between Bsal presence and high trail density, suggesting that human-mediated spread may increase risk for spillover between populations. We then use distribution modeling to show that favorable conditions occur in lowlands influenced by the North Sea, where increased survey effort is needed to determine how Bsal impacts local newt populations, but also in hill- and mountain ranges in northeastern France and the lower half of Germany. Finally, connectivity analyses suggest that these hill- and mountain ranges may act as stepping stones for further spread southward. Our results provide initial insight into regional environmental conditions underlying Bsal epizootics, present updated invasibility predictions for northwestern Europe, and lead us to discuss a wide variety of potential survey and research actions needed to advance future conservation and mitigation efforts.
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Affiliation(s)
- Wouter Beukema
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
- Naturalis Biodiversity Center, P.O. Box␣9517, Leiden, 2300RA, the Netherlands
| | - Jesse Erens
- Naturalis Biodiversity Center, P.O. Box␣9517, Leiden, 2300RA, the Netherlands
| | - Vanessa Schulz
- Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Talstrasse 33, Leipzig, 04103, Germany
- Technische Universität Braunschweig, Division of Evolutionary Biology, Zoological Institute, Mendelssohnstrasse 4, Braunschweig, 38106, Germany
| | - Gwij Stegen
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | | | - Tariq Stark
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Toernooiveld 1, Nijmegen, 6525ED, the Netherlands
| | - Arnaud Laudelout
- Reptile, Amphibian & Fish Conservation Netherlands (RAVON), Toernooiveld 1, Nijmegen, 6525ED, the Netherlands
| | - Thierry Kinet
- Natagora, Traverse des Muses 1, Namur, 5000, Belgium
| | - Tom Kirschey
- Nature and Biodiversity Conservation Union (NABU), Charitéstrasse 3, Berlin, 10117, Germany
| | - Marie Poulain
- Biogeography and Vertebrate Ecology, CEFE, EPHE-PSL, CNRS, University of Montpellier, Paul Valéry University Montpellier III, 1919 route de Mende, Montpellier, 34293, France
| | - Claude Miaud
- Biogeography and Vertebrate Ecology, CEFE, EPHE-PSL, CNRS, University of Montpellier, Paul Valéry University Montpellier III, 1919 route de Mende, Montpellier, 34293, France
| | - Sebastian Steinfartz
- Molecular Evolution and Systematics of Animals, Institute of Biology, University of Leipzig, Talstrasse 33, Leipzig, 04103, Germany
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
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14
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Rothstein AP, Byrne AQ, Knapp RA, Briggs CJ, Voyles J, Richards-Zawacki CL, Rosenblum EB. Divergent regional evolutionary histories of a devastating global amphibian pathogen. Proc Biol Sci 2021; 288:20210782. [PMID: 34157877 PMCID: PMC8220259 DOI: 10.1098/rspb.2021.0782] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Emerging infectious diseases are a pressing threat to global biological diversity. Increased incidence and severity of novel pathogens underscores the need for methodological advances to understand pathogen emergence and spread. Here, we use genetic epidemiology to test, and challenge, key hypotheses about a devastating zoonotic disease impacting amphibians globally. Using an amplicon-based sequencing method and non-invasive samples we retrospectively explore the history of the fungal pathogen Batrachochytrium dendrobatidis (Bd) in two emblematic amphibian systems: the Sierra Nevada of California and Central Panama. The hypothesis in both regions is the hypervirulent Global Panzootic Lineage of Bd (BdGPL) was recently introduced and spread rapidly in a wave-like pattern. Our data challenge this hypothesis by demonstrating similar epizootic signatures can have radically different underlying evolutionary histories. In Central Panama, our genetic data confirm a recent and rapid pathogen spread. However, BdGPL in the Sierra Nevada has remarkable spatial structuring, high genetic diversity and a relatively older history inferred from time-dated phylogenies. Thus, this deadly pathogen lineage may have a longer history in some regions than assumed, providing insights into its origin and spread. Overall, our results highlight the importance of integrating observed wildlife die-offs with genetic data to more accurately reconstruct pathogen outbreaks.
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Affiliation(s)
- Andrew P Rothstein
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, USA.,Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA
| | - Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, USA.,Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA.,Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
| | - Roland A Knapp
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, CA, USA.,Earth Research Institute, University of California, Santa Barbara, CA, USA
| | - Cheryl J Briggs
- Earth Research Institute, University of California, Santa Barbara, CA, USA.,Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV, USA
| | | | - Erica Bree Rosenblum
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, USA.,Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA
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15
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Delazeri F, Ernetti JR, De Bastiani VIM, Lingnau R, Toledo LF, Lucas EM. Forest cover influences chytrid infections in populations of Boana curupi, a threatened treefrog of south Brazil. DISEASES OF AQUATIC ORGANISMS 2021; 144:133-142. [PMID: 33955851 DOI: 10.3354/dao03585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Complex interactions among hosts, pathogens, and the environment affect the vulnerability of amphibians to the emergence of infectious diseases such as chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Boana curupi is a forest-dwelling amphibian endemic to the southern Atlantic Forest of South America, a severely fragmented region. Here, we evaluated whether abiotic factors (including air and water temperature, relative air humidity, and landscape) are correlated with chytrid infection intensity and prevalence in B. curupi. We found individuals infected with Bd in all populations sampled. Prevalence ranged from 25-86%, and the infection burden ranged from 1 to over 130000 zoospore genomic equivalents (g.e.) (mean ± SD: 4913 ± 18081 g.e.). The infection load differed among populations and was influenced by forest cover at scales of 100, 500, and 1000 m, with the highest infection rates recorded in areas with a higher proportion of forest cover. Our results suggest that the fungus is widely distributed in the populations of B. curupi in southern Brazil. Population and disease monitoring are necessary to better understand the relationships between host, pathogen, and environment, especially when, as in the case of B. curupi, threatened species are involved.
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Affiliation(s)
- Francieli Delazeri
- Programa de Pós-graduação em Ciências Ambientais, Universidade Comunitária da Região de Chapecó, Chapecó, Santa Catarina 89809-900, Brazil
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16
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Whitfield SM, Alvarado-Barboza G, Abarca JG, Zumbado-Ulate H, Jimenez RR, Kerby J. Ranavirus is widespread in Costa Rica and co-occurs with threatened amphibians. DISEASES OF AQUATIC ORGANISMS 2021; 144:89-98. [PMID: 33830072 DOI: 10.3354/dao03576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
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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17
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Granados-Martínez S, Zumbado-Ulate H, Searle CL, Oliveira BF, García-Rodríguez A. Niche Contraction of an Endangered Frog Driven by the Amphibian Chytrid Fungus. ECOHEALTH 2021; 18:134-144. [PMID: 34184170 DOI: 10.1007/s10393-021-01525-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 06/13/2023]
Abstract
Introduced pathogens can alter the geographic distribution of susceptible host species. For example, Batrachochytrium dendrobatidis (Bd) is a fungal pathogen that has been linked to the global decline and extinction of numerous amphibian species during the last four decades. A growing number of studies have described the distribution of Bd and susceptible hosts across the globe; however, knowledge on how Bd may shape the climatic niche of susceptible species is still missing. We estimated the effect of Bd on the geographic distribution and niche dynamics of the critically endangered lowland robber frog (Craugastor ranoides) in Costa Rica. We found a reduction of 98% in the geographic range of this species by 1995, following the epizootic outbreaks of Bd that affected Costa Rica in the 1980 and early 1990s. We also quantified niche contraction and found that the species is currently restricted to dry and warm environments that have been considered unsuitable for Bd. Our results contribute to the understanding of how emerging pathogens shape the climatic niches and geographic distribution of susceptible species.
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Affiliation(s)
- Sofía Granados-Martínez
- Escuela de Biología, Universidad de Costa Rica, Montes de Oca, San Pedro, San José, 11501-2060, Costa Rica.
- Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José, 11501, Costa Rica.
| | - Héctor Zumbado-Ulate
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Catherine L Searle
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - Brunno F Oliveira
- Environmental Science and Policy Department, University of California Davis, Davis, CA, USA
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, 59078-900, Brazil
| | - Adrián García-Rodríguez
- Escuela de Biología, Universidad de Costa Rica, Montes de Oca, San Pedro, San José, 11501-2060, Costa Rica
- Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, 59078-900, Brazil
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
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18
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Rahman MM, Jahan H, Rabbe MF, Chakraborty M, Salauddin M. First Detection of Batrachochytrium dendrobatidis in Wild Frogs from Bangladesh. ECOHEALTH 2021; 18:31-43. [PMID: 34028636 DOI: 10.1007/s10393-021-01522-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 02/25/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Global amphibian populations are facing a novel threat, chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), which is responsible for the severe decline of a number of species across several continents. Chytridiomycosis in Asia is a relatively recent discovery yet there have been no reports on Bd-presence in Bangladeshi amphibians. We conducted a preliminary study on 133 wild frogs from seven sites in Bangladesh between April and July 2018. Nested PCR analysis showed 20 samples (15.04%) and 50% of the tested taxa (9 species from 6 genera and 4 families) as Bd-positive. Eight of the nine species are discovered as newly infected hosts. Analysis of Bd-positive samples shows prevalence does not significantly vary among different land cover categories, although the occurrence is higher in forested areas. The prevalence rate is similar in high and low disturbed areas, but the range of occurrence is statistically higher in low disturbance areas. Maximum entropy distribution modeling indicates high probabilities of Bd occurrence in hilly and forested areas in southeast and central-north Bangladesh. The Bd-specific ITS1-5.8S-ITS2 ribosomal gene sequence from the Bd-positive samples tested is completely identical. A neighbor-joining phylogenetic tree reveals that the identified strain shares a common ancestry with strains previously discovered in different Asian regions. Our results provide the first evidence of Bd-presence in Bangladeshi amphibians, inferring that diversity is at risk. The effects of environmental and climatic factors along with quantitative PCR analysis are required to determine the infection intensity and susceptibility of amphibians in the country.
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Affiliation(s)
- Md Mokhlesur Rahman
- Department of Zoology, University of Dhaka, Dhaka, 1000, Bangladesh.
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK.
| | - Hawa Jahan
- Department of Zoology, University of Dhaka, Dhaka, 1000, Bangladesh
- Division of Evolution and Genomic Sciences, FBMH, School of Biological Sciences, University of Manchester, Oxford Rd, Manchester, M13 9PT, UK
| | - Md Fazle Rabbe
- Department of Zoology, University of Dhaka, Dhaka, 1000, Bangladesh
| | | | - Md Salauddin
- Department of Geography and Environment, Jagannath University, Dhaka, 1100, Bangladesh
- Disaster Risk Management Department, Bangladesh Red Crescent Society, Red Crescent Sarak, Bara Moghbazar, Dhaka, 1217, Bangladesh
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19
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Abarca JG, Whitfield SM, Zuniga-Chaves I, Alvarado G, Kerby J, Murillo-Cruz C, Pinto-Tomás AA. Genotyping and differential bacterial inhibition of Batrachochytrium dendrobatidis in threatened amphibians in Costa Rica. MICROBIOLOGY-SGM 2021; 167. [PMID: 33529150 DOI: 10.1099/mic.0.001017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized - genetically and morphologically - several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL-2, which has been related to massive amphibian deaths worldwide; however, the isolates obtained showed genetic and morphological variation. Furthermore, we isolated epidermal bacteria from 12 amphibian species of surviving populations, some in danger of extinction, and evaluated their inhibitory activity against the collection of chytrid isolates. Through bioassays we confirmed the presence of chytrid-inhibitory bacterial genera in Costa Rican amphibians. However, we observed that the inhibition varied between different isolates of the same bacterial genus, and each bacterial isolation inhibited fungal isolation differently. In total, 14 bacterial isolates belonging to the genera Stenotrophomonas, Streptomyces, Enterobacter, Pseudomonas and Klebsiella showed inhibitory activity against all Bd isolates. Given the observed variation both in the pathogen and in the bacterial inhibition capacity, it is highly relevant to include local isolates and to consider the origin of the microorganisms when performing in vivo infection tests aimed at developing and implementing mitigation strategies for chytridiomycosis.
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Affiliation(s)
- Juan G Abarca
- Laboratorio de Recursos Naturales y Vida Silvestre (LARNAVISI), Escuela de Ciencias Biológicas, Universidad Nacional, Heredia, Costa Rica
| | - Steven M Whitfield
- Conservation and Research Department, Zoo Miami, St, Miami, FL 33177, USA
| | - Ibrahim Zuniga-Chaves
- Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica, San Pedro, Costa Rica.,Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Gilbert Alvarado
- Laboratorio de Patología Experimental y Comparada (LAPECOM), Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Jacob Kerby
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA
| | - Catalina Murillo-Cruz
- Centro de Investigación en Estructuras Microscópicas (CIEMic), Universidad de Costa Rica, San Pedro, Costa Rica.,Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica, San Pedro, Costa Rica
| | - Adrián A Pinto-Tomás
- Centro de Investigación en Estructuras Microscópicas (CIEMic), Universidad de Costa Rica, San Pedro, Costa Rica.,Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica, San Pedro, Costa Rica.,Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San Pedro, Costa Rica
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20
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Continued preference for suboptimal habitat reduces bat survival with white-nose syndrome. Nat Commun 2021; 12:166. [PMID: 33420005 PMCID: PMC7794521 DOI: 10.1038/s41467-020-20416-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 11/23/2020] [Indexed: 12/27/2022] Open
Abstract
Habitat alteration can influence suitability, creating ecological traps where habitat preference and fitness are mismatched. Despite their importance, ecological traps are notoriously difficult to identify and their impact on host–pathogen dynamics remains largely unexplored. Here we assess individual bat survival and habitat preferences in the midwestern United States before, during, and after the invasion of the fungal pathogen that causes white-nose syndrome. Despite strong selection pressures, most hosts continued to select habitats where disease severity was highest and survival was lowest, causing continued population declines. However, some individuals used refugia where survival was higher. Over time, a higher proportion of the total population used refugia than before pathogen arrival. Our results demonstrate that host preferences for habitats with high disease-induced mortality can create ecological traps that threaten populations, even in the presence of accessible refugia. Temperature-dependent host–pathogen interactions may lead species to shift their thermal preferences under pathogen pressure. However, here the authors show that bats have not altered their microclimate preferences due to temperature-mediated mortality from white-nose syndrome, finding instead a sustained preference for warmer sites with high mortality.
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21
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Willcock S, Hooftman DAP, Blanchard R, Dawson TP, Hickler T, Lindeskog M, Martinez-Lopez J, Reyers B, Watts SM, Eigenbrod F, Bullock JM. Ensembles of ecosystem service models can improve accuracy and indicate uncertainty. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 747:141006. [PMID: 32768767 DOI: 10.1016/j.scitotenv.2020.141006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/14/2020] [Accepted: 07/14/2020] [Indexed: 05/22/2023]
Abstract
Many ecosystem services (ES) models exist to support sustainable development decisions. However, most ES studies use only a single modelling framework and, because of a lack of validation data, rarely assess model accuracy for the study area. In line with other research themes which have high model uncertainty, such as climate change, ensembles of ES models may better serve decision-makers by providing more robust and accurate estimates, as well as provide indications of uncertainty when validation data are not available. To illustrate the benefits of an ensemble approach, we highlight the variation between alternative models, demonstrating that there are large geographic regions where decisions based on individual models are not robust. We test if ensembles are more accurate by comparing the ensemble accuracy of multiple models for six ES against validation data across sub-Saharan Africa with the accuracy of individual models. We find that ensembles are better predictors of ES, being 5.0-6.1% more accurate than individual models. We also find that the uncertainty (i.e. variation among constituent models) of the model ensemble is negatively correlated with accuracy and so can be used as a proxy for accuracy when validation is not possible (e.g. in data-deficient areas or when developing scenarios). Since ensembles are more robust, accurate and convey uncertainty, we recommend that ensemble modelling should be more widely implemented within ES science to better support policy choices and implementation.
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Affiliation(s)
- Simon Willcock
- School of Natural Sciences, Bangor University, United Kingdom; Biological Sciences, University of Southampton, United Kingdom.
| | - Danny A P Hooftman
- Lactuca: Environmental Data Analyses and Modelling, the Netherlands; UK Centre for Ecology and Hydrology, Wallingford OX10 8BB, United Kingdom.
| | - Ryan Blanchard
- Council for Scientific and Industrial Research, South Africa.
| | | | - Thomas Hickler
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Germany; Department of Physical Geography, Goethe University, Frankfurt, Germany.
| | - Mats Lindeskog
- Department of Physical Geography and Ecosystem Science, Lund University, Sweden.
| | - Javier Martinez-Lopez
- Soil Erosion and Conservation Research Group, CEBAS-CSIC, Spanish Research Council, Campus de Espinardo, Murcia E-30100, PO Box 164, Spain; BC3 - Basque Centre for Climate Change, 48940 Leioa, Spain.
| | - Belinda Reyers
- Future Africa, University of Pretoria, Private bag X20, Hatfield 0028, South Africa; Stockholm Resilience Centre, Stockholm University, Stockholm SE-10691, Sweden.
| | - Sophie M Watts
- Biological Sciences, University of Southampton, United Kingdom
| | - Felix Eigenbrod
- Biological Sciences, University of Southampton, United Kingdom; Geography and Environment, University of Southampton, United Kingdom.
| | - James M Bullock
- UK Centre for Ecology and Hydrology, Wallingford OX10 8BB, United Kingdom.
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22
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Sonn JM, Porter WP, Mathewson PD, Richards-Zawacki CL. Predictions of Disease Risk in Space and Time Based on the Thermal Physiology of an Amphibian Host-Pathogen Interaction. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.576065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Emerging infectious diseases have been responsible for declines and extinctions in a growing number of species. Predicting disease variables like infection prevalence and mortality and how they vary in space and time will be critical to understanding how host-pathogen dynamics play out in natural environments and will help to inform management actions. The pandemic disease chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd), has been implicated in declines in hundreds of amphibian species worldwide. We used field-collected measurements of host body temperatures and other physiological parameters to develop a mechanistic model of disease risk in a declining amphibian, the Northern cricket frog (Acris crepitans). We first used a biophysical model to predict host body temperatures across the species range in the eastern United States. We then used empirically derived relationships between host body temperature, infection prevalence and survival to predict where and when the risk of Bd-related declines is greatest. Our model predicts that pathogen prevalence is greatest, and survival of infected A. crepitans frogs is lowest, just prior to breeding when host body temperatures are low. Taken together, these results suggest that Bd poses the greatest threat to short-lived A. crepitans populations in the northern part of this host’s range and that disease-related recruitment failure may be common. Furthermore, our study demonstrates the utility of mechanistic modeling approaches for predicting disease outbreaks and dynamics in animal hosts.
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23
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Brannelly LA, McCallum HI, Grogan LF, Briggs CJ, Ribas MP, Hollanders M, Sasso T, Familiar López M, Newell DA, Kilpatrick AM. Mechanisms underlying host persistence following amphibian disease emergence determine appropriate management strategies. Ecol Lett 2020; 24:130-148. [PMID: 33067922 DOI: 10.1111/ele.13621] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/18/2020] [Accepted: 09/08/2020] [Indexed: 12/19/2022]
Abstract
Emerging infectious diseases have caused many species declines, changes in communities and even extinctions. There are also many species that persist following devastating declines due to disease. The broad mechanisms that enable host persistence following declines include evolution of resistance or tolerance, changes in immunity and behaviour, compensatory recruitment, pathogen attenuation, environmental refugia, density-dependent transmission and changes in community composition. Here we examine the case of chytridiomycosis, the most important wildlife disease of the past century. We review the full breadth of mechanisms allowing host persistence, and synthesise research on host, pathogen, environmental and community factors driving persistence following chytridiomycosis-related declines and overview the current evidence and the information required to support each mechanism. We found that for most species the mechanisms facilitating persistence have not been identified. We illustrate how the mechanisms that drive long-term host population dynamics determine the most effective conservation management strategies. Therefore, understanding mechanisms of host persistence is important because many species continue to be threatened by disease, some of which will require intervention. The conceptual framework we describe is broadly applicable to other novel disease systems.
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Affiliation(s)
- Laura A Brannelly
- Veterinary BioSciences, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic, 3030, Australia
| | - Hamish I McCallum
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia
| | - Laura F Grogan
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia.,Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Cheryl J Briggs
- Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Maria P Ribas
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia.,Wildlife Conservation Medicine Research Group, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain
| | - Matthijs Hollanders
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Thais Sasso
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia
| | - Mariel Familiar López
- School of Environment and Sciences, Griffith University, Gold Coast, Qld., 4215, Australia
| | - David A Newell
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Auston M Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
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24
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Zumbado‐Ulate H, García‐Rodríguez A, Searle CL. Species distribution models predict the geographic expansion of an enzootic amphibian pathogen. Biotropica 2020. [DOI: 10.1111/btp.12863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Adrián García‐Rodríguez
- Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de MéxicoUNAM Ciudad de México México
- Museo de Zoología Escuela de Biología Universidad de Costa Rica San José Costa Rica
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25
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Bell SC, Heard GW, Berger L, Skerratt LF. Connectivity over a disease risk gradient enables recovery of rainforest frogs. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02152. [PMID: 32343856 DOI: 10.1002/eap.2152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Chytridiomycosis has been a key driver of global frog declines and extinctions, particularly for high-altitude populations across Australia and the Americas. While recent evidence shows some species are recovering, the extent of such recoveries and the mechanisms underpinning them remain poorly resolved. We surveyed the historical latitudinal and elevational range of four Australian rainforest frogs that disappeared from upland sites between 1989 and 1994 to establish their contemporary distribution and elevational limits, and investigate factors affecting population recovery. Five rainforest streams were surveyed from mountain-base to summit (30 sites in total), with swabs collected from the target species (Litoria dayi, L. nannotis, L. rheocola, and L. serrata) to determine their infection status, and data loggers deployed to measure microclimatic variation across the elevational gradient. Infection probability increased with elevation and canopy cover as it was tightly and inversely correlated with stream-side air temperature. Occupancy patterns suggest varying responses to this disease threat gradient. Two species, L. rheocola and L. serrata, were found over their full historical elevational range (≥1,000 m above sea level [asl]), while L. dayi was not detected above 400 m (formerly known up to 900 m asl) and L. nannotis was not detected above 800 m (formerly known up to 1,200 m asl). Site occupancy probability was negatively related to predicted infection prevalence for L. dayi, L. nannotis, and L. rheocola, but not L. serrata, which appears to now tolerate high fungal burdens. This study highlights the importance of environmental refuges and connectivity across disease risk gradients for the persistence and natural recovery of frogs susceptible to chytridiomycosis. Likewise, in documenting both interspecific variation in recovery rates and intraspecific differences between sites, this study suggests interactions between disease threats and host selection exist that could be manipulated. For example, translocations may be warranted where connectivity is poor or the increase in disease risk is too steep to allow recolonization, combined with assisted selection or use of founders from populations that have already undergone natural selection.
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Affiliation(s)
- Sara C Bell
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Geoffrey W Heard
- Institute of Land, Water and Society, Charles Sturt University, Albury, New South Wales, 2640, Australia
- Victorian Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, 3084, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
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26
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Challenges and Opportunities for Terrapene carolina carolina Under Different Climate Scenarios. REMOTE SENSING 2020. [DOI: 10.3390/rs12050836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An unprecedented rate of global climate change as a result of human impacts has affected both endotherms and ectotherms. This is of special concern for ectotherms, such as reptiles, as these species are suffering from large population declines and lack the dispersal ability of other taxa. There are many protected areas across the United States; however, these areas are fragmented, which hinders dispersal. We examined species distribution and dispersal capabilities for Terrapene carolina carolina, a relatively narrow range, low dispersal, and vulnerable species. We created climatic suitability models to predict changes in suitable habitat and identified important predictor variables. We modeled three time periods using MaxEnt and hypothesized that there would be an increase in northern habitat. We found that most of the suitable habitat changed at the northern end of the range and that mean temperature of driest quarter had the most influence on future predictions. Overall there were relatively moderate changes in suitable habitat, but where these changes occur affects accessibility. As an example, we examined these local scale movements within Oak Openings Region and found that individuals are capable of dispersing to new suitable habitats; however, other physical barriers will hinder movements. In conclusion, there is a critical need to protect this vulnerable reptilian species and our results suggest that T. c. carolina will expand their distribution northward. We suggest that land managers increase connectivity among protected areas to facilitate dispersal, but future studies should incorporate other dynamic ecological factors at finer spatial scale.
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27
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Huml JV, Harris WE, Taylor MI, Sen R, Prudhomme C, Ellis JS. Pollution control can help mitigate future climate change impact on European grayling in the UK. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- J. Vanessa Huml
- School of Science & Environment Manchester Metropolitan University Manchester UK
- School of Biological and Marine Sciences University of Plymouth Plymouth UK
| | - W. Edwin Harris
- Crop and Environment Sciences Harper Adams University Edgmond UK
| | - Martin I. Taylor
- School of Biological Sciences University of East Anglia Norwich UK
| | - Robin Sen
- School of Science & Environment Manchester Metropolitan University Manchester UK
| | | | - Jonathan S. Ellis
- School of Biological and Marine Sciences University of Plymouth Plymouth UK
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28
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McMillan KM, Lesbarrères D, Harrison XA, Garner TWJ. Spatiotemporal heterogeneity decouples infection parameters of amphibian chytridiomycosis. J Anim Ecol 2020; 89:1109-1121. [PMID: 31872434 DOI: 10.1111/1365-2656.13170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 11/01/2019] [Indexed: 11/27/2022]
Abstract
Emerging infectious diseases are responsible for declines in wildlife populations around the globe. Mass mortality events associated with emerging infectious diseases are often associated with high number of infected individuals (prevalence) and high pathogen loads within individuals (intensity). At the landscape scale, spatial and temporal variation in environmental conditions can alter the relationship between these infection parameters and blur the overall picture of disease dynamics. Quantitative estimates of how infection parameters covary with environmental heterogeneity at the landscape scale are scarce. If we are to identify wild populations at risk of disease epidemics, we must elucidate the factors that shape, and potentially decouple, the link between pathogen prevalence and intensity of infection over complex ecological landscapes. Using a network of 41 populations of the amphibian host Rana pipiens in Ontario, Canada, we present the spatial and temporal heterogeneity in pathogen prevalence and intensity of infection of the chytrid fungus Batrachochytrium dendrobatidis (Bd), across a 3-year period. We then quantify how covariation between both infection parameters measured during late summer is modified by previously experienced spatiotemporal environmental heterogeneity across 14 repeat sampled populations. Late summer Bd infection parameters are governed, at least in part, by different environmental factors operating during separate host life-history events. Our results provide evidence for a relationship between Bd prevalence and thermal regimes prior to host breeding at the site level, and a relationship between intensity of infection and aquatic conditions (precipitation, hydroshed size and river density) throughout host breeding period at the site level. This demonstrates that microclimatic variation within temporal windows can drive divergent patterns of pathogen dynamics within and across years, by effecting changes in host behaviour which interfere with the pathogen's ability to infect and re-infect hosts. A clearer understanding of the role that spatiotemporal heterogeneity has upon infection parameters will provide valuable insights into host-pathogen epidemiology, as well as more fundamental aspects of the ecology and evolution of interspecific interactions.
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Affiliation(s)
- Kirsten M McMillan
- Institute of Zoology, Zoological Society of London, London, UK.,Department of Biology, Laurentian University, Sudbury, ON, Canada
| | | | - Xavier A Harrison
- Institute of Zoology, Zoological Society of London, London, UK.,University of Exeter, Exeter, UK
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29
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De León ME, Zumbado-Ulate H, García-Rodríguez A, Alvarado G, Sulaeman H, Bolaños F, Vredenburg VT. Batrachochytrium dendrobatidis infection in amphibians predates first known epizootic in Costa Rica. PLoS One 2019; 14:e0208969. [PMID: 31821326 PMCID: PMC6903748 DOI: 10.1371/journal.pone.0208969] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 10/18/2019] [Indexed: 11/19/2022] Open
Abstract
Emerging infectious diseases are a growing threat to biodiversity worldwide. Outbreaks of the infectious disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), are implicated in the decline and extinction of numerous amphibian species. In Costa Rica, a major decline event occurred in 1987, more than two decades before this pathogen was discovered. The loss of many species in Costa Rica is assumed to be due to Bd-epizootics, but there are few studies that provide data from amphibians in the time leading up to the proposed epizootics. In this study, we provide new data on Bd infection rates of amphibians collected throughout Costa Rica, in the decades prior to the epizootics. We used a quantitative PCR assay to test for Bd presence in 1016 anuran museum specimens collected throughout Costa Rica. The earliest specimen that tested positive for Bd was collected in 1964. Across all time periods, we found an overall infection rate (defined as the proportion of Bd-positive individuals) of 4%. The number of infected individuals remained relatively low across all species tested and the range of Bd-positive specimens was shown to be geographically constrained up until the 1980s; when epizootics are hypothesized to have occurred. After that time, infection rate increased three-fold, and the range of specimens tested positive for Bd increased, with Bd-positive specimens collected across the entire country. Our results suggest that Bd dynamics in Costa Rica are more complicated than previously thought. The discovery of Bd's presence in the country preceding massive declines leads to a number of different hypotheses: 1) Bd invaded Costa Rica earlier than previously known, and spread more slowly than previously reported; 2) Bd invaded multiple times and faded out; 3) an endemic Bd lineage existed; 4) an earlier Bd lineage evolved into the current Bd lineage or hybridized with an invasive lineage; or 5) an earlier Bd lineage went extinct and a new invasion event occurred causing epizootics. To help visualize areas where future studies should take place, we provide a Bd habitat suitability model trained with local data. Studies that provide information on genetic lineages of Bd are needed to determine the most plausible spatial-temporal, host-pathogen dynamics that could best explain the epizootics resulting in amphibian declines in Costa Rica and throughout Central America.
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Affiliation(s)
- Marina E. De León
- Department of Microbiology and Molecular genetics, University of California, Davis, United States of America
| | - Héctor Zumbado-Ulate
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Adrián García-Rodríguez
- Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gilbert Alvarado
- Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
- Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Hasan Sulaeman
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Federico Bolaños
- Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
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30
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Sonn JM, Utz RM, Richards‐Zawacki CL. Effects of latitudinal, seasonal, and daily temperature variations on chytrid fungal infections in a North American frog. Ecosphere 2019. [DOI: 10.1002/ecs2.2892] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Julia M. Sonn
- Department of Ecology and Evolutionary Biology Tulane University New Orleans Louisiana USA
| | - Ryan M. Utz
- Falk School of Sustainability Chatham University Gibsonia Pennsylvania USA
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31
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Hernández-Martínez LÁ, Romero-Méndez U, González-Barrios JL, García-De la Peña MC, Amézquita-Torres A. Nuevos registros y prevalencia de Batrachochytrium dendrobatidis en anuros de la cuenca Nazas-Aguanaval en la región norte-centro de México. REV MEX BIODIVERS 2019. [DOI: 10.22201/ib.20078706e.2019.90.2934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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32
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Jiménez RR, Alvarado G, Estrella J, Sommer S. Moving Beyond the Host: Unraveling the Skin Microbiome of Endangered Costa Rican Amphibians. Front Microbiol 2019; 10:2060. [PMID: 31572313 PMCID: PMC6751270 DOI: 10.3389/fmicb.2019.02060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/21/2019] [Indexed: 01/12/2023] Open
Abstract
Some neotropical amphibians, including a few species in Costa Rica, were presumed to be "extinct" after dramatic population declines in the late 1980s but have been rediscovered in isolated populations. Such populations seem to have evolved a resistance/tolerance to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes a deadly skin disease and is considered one of the main drivers of worldwide amphibian declines. The skin microbiome is an important component of the host's innate immune system and is associated with Bd-resistance. However, the way that the bacterial diversity of the skin microbiome confers protection against Bd in surviving species remains unclear. We studied variation in the skin microbiome and the prevalence of putatively anti-Bd bacterial taxa in four co-habiting species in the highlands of the Juan Castro Blanco National Park in Costa Rica using 16S rRNA amplicon sequencing. Lithobates vibicarius, Craugastor escoces, and Isthmohyla rivularis have recently been rediscovered, whereas Isthmohyla pseudopuma has suffered population fluctuations but has never disappeared. To investigate the life stage at which the protective skin microbiome is shaped and when shifts occur in the diversity of putatively anti-Bd bacteria, we studied the skin microbiome of tadpoles, juveniles and adults of L. vibicarius. We show that the skin bacterial composition of sympatric species and hosts with distinct Bd-infection statuses differs at the phyla, family, and genus level. We detected 94 amplicon sequence variants (ASVs) with putative anti-Bd activity pertaining to distinct bacterial taxa, e.g., Pseudomonas spp., Acinetobacter johnsonii, and Stenotrophomonas maltophilia. Bd-uninfected L. vibicarius harbored 79% more putatively anti-Bd ASVs than Bd-infected individuals. Although microbiome composition and structure differed across life stages, the diversity of putative anti-Bd bacteria was similar between pre- and post-metamorphic stages of L. vibicarius. Despite low sample size, our results support the idea that the skin microbiome is dynamic and protects against ongoing Bd presence in endangered species persisting after their presumed extinction. Our study serves as a baseline to understand the microbial patterns in species of high conservation value. Identification of microbial signatures linked to variation in disease susceptibility might, therefore, inform mitigation strategies for combating the global decline of amphibians.
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Affiliation(s)
- Randall R. Jiménez
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Gilbert Alvarado
- Laboratory of Comparative Wildlife Pathology, School of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Josimar Estrella
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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33
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Scheele BC, Pasmans F, Skerratt LF, Berger L, Martel A, Beukema W, Acevedo AA, Burrowes PA, Carvalho T, Catenazzi A, De la Riva I, Fisher MC, Flechas SV, Foster CN, Frías-Álvarez P, Garner TWJ, Gratwicke B, Guayasamin JM, Hirschfeld M, Kolby JE, Kosch TA, La Marca E, Lindenmayer DB, Lips KR, Longo AV, Maneyro R, McDonald CA, Mendelson J, Palacios-Rodriguez P, Parra-Olea G, Richards-Zawacki CL, Rödel MO, Rovito SM, Soto-Azat C, Toledo LF, Voyles J, Weldon C, Whitfield SM, Wilkinson M, Zamudio KR, Canessa S. Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity. Science 2019; 363:1459-1463. [PMID: 30923224 DOI: 10.1126/science.aav0379] [Citation(s) in RCA: 537] [Impact Index Per Article: 107.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/06/2019] [Indexed: 12/18/2022]
Abstract
Anthropogenic trade and development have broken down dispersal barriers, facilitating the spread of diseases that threaten Earth's biodiversity. We present a global, quantitative assessment of the amphibian chytridiomycosis panzootic, one of the most impactful examples of disease spread, and demonstrate its role in the decline of at least 501 amphibian species over the past half-century, including 90 presumed extinctions. The effects of chytridiomycosis have been greatest in large-bodied, range-restricted anurans in wet climates in the Americas and Australia. Declines peaked in the 1980s, and only 12% of declined species show signs of recovery, whereas 39% are experiencing ongoing decline. There is risk of further chytridiomycosis outbreaks in new areas. The chytridiomycosis panzootic represents the greatest recorded loss of biodiversity attributable to a disease.
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Affiliation(s)
- Ben C Scheele
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia. .,National Environmental Science Programme, Threatened Species Recovery Hub, Canberra, ACT 2601, Australia.,One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Wouter Beukema
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Aldemar A Acevedo
- Programa de Doctorado en Ciencias Biológicas, Laboratorio de Biología Evolutiva, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago, Chile.,Grupo de Investigación en Ecología y Biogeografía, Universidad de Pamplona, Barrio El Buque, Km 1, Vía a Bucaramanga, Pamplona, Colombia
| | - Patricia A Burrowes
- Department of Biology, University of Puerto Rico, P.O. Box 23360, San Juan, Puerto Rico
| | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Alessandro Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
| | - Ignacio De la Riva
- Museo Nacional de Ciencias Naturales-CSIC, C/ José Gutiérrez Abascal 2, Madrid 28006, Spain
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia.,Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Sede Venado de Oro, Paseo Bolívar 16-20, Bogotá, Colombia
| | - Claire N Foster
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia
| | - Patricia Frías-Álvarez
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society London, Regents Park, London NW1 4RY, UK.,Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Brian Gratwicke
- Smithsonian National Zoological Park and Conservation Biology Institute, Washington, DC 20008, USA
| | - Juan M Guayasamin
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto de Investigaciones Biológicas y Ambientales BIOSFERA, Laboratorio de Biología Evolutiva, Campus Cumbayá, Quito, Ecuador.,Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb), Ingeniería en Biodiversidad y Cambio Climático, Facultad de Medio Ambiente, Universidad Tecnológica Indoamérica, Calle Machala y Sabanilla, Quito, Ecuador.,Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Mareike Hirschfeld
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, Berlin 10115, Germany
| | - Jonathan E Kolby
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia.,Honduras Amphibian Rescue and Conservation Center, Lancetilla Botanical Garden and Research Center, Tela, Honduras.,The Conservation Agency, Jamestown, RI 02835, USA
| | - Tiffany A Kosch
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia.,AL Rae Centre for Genetics and Breeding, Massey University, Palmerston North 4442, New Zealand
| | - Enrique La Marca
- School of Geography, Faculty of Forestry Engineering and Environmental Sciences, University of Los Andes, Merida, Venezuela
| | - David B Lindenmayer
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia.,National Environmental Science Programme, Threatened Species Recovery Hub, Canberra, ACT 2601, Australia
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Raúl Maneyro
- Laboratorio de Sistemática e Historia Natural de Vertebrados. Facultad de Ciencias, Universidad de la República. Igua 4225, CP 11400, Montevideo, Uruguay
| | - Cait A McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Joseph Mendelson
- Zoo Atlanta, Atlanta, GA 30315, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | | | - Gabriela Parra-Olea
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, México
| | | | - Mark-Oliver Rödel
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, Berlin 10115, Germany
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, km 9.6 Libramiento Norte Carretera Irapuato-León, Irapuato, Guanajuato CP36824, México
| | - Claudio Soto-Azat
- Centro de Investigación para la Sustentabilidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370251, Chile
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Ché Weldon
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Steven M Whitfield
- Zoo Miami, Conservation and Research Department, Miami, FL 33177, USA.,Florida International University School of Earth, Environment, and Society, 11200 SW 8th St., Miami, FL 33199, USA
| | - Mark Wilkinson
- Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Stefano Canessa
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
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34
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Endemic Infection of Batrachochytrium dendrobatidis in Costa Rica: Implications for Amphibian Conservation at Regional and Species Level. DIVERSITY 2019. [DOI: 10.3390/d11080129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
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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35
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Climate change will decrease the range size of snake species under negligible protection in the Brazilian Atlantic Forest hotspot. Sci Rep 2019; 9:8523. [PMID: 31189933 PMCID: PMC6561978 DOI: 10.1038/s41598-019-44732-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 05/23/2019] [Indexed: 11/24/2022] Open
Abstract
Reptiles are highly susceptible to climate change, responding negatively to thermal and rainfall alterations mainly in relation to their reproductive processes. Based on that, we evaluated the effects of climate change on climatically suitable areas for the occurrence of snakes in the Atlantic Forest hotspot, considering the responses of distinct reproductive groups (oviparous and viviparous). We assessed the species richness and turnover patterns affected by climate change and projected the threat status of each snake species at the end of the century. We also evaluated the effectiveness of the protected areas in safeguarding the species by estimating the mean percentage overlap between snake species distribution and protected areas (PAs) network and by assessing whether such areas will gain or lose species under climate change. Our results showed greater species richness in the eastern-central portion of the Atlantic Forest at present. In general, we evidenced a drastic range contraction of the snake species under climate change. Temporal turnover tends to be high in the western and north-eastern edges of the biome, particularly for oviparous species. Our predictions indicate that 73.6% of oviparous species and 67.6% of viviparous species could lose at least half of their original range by 2080. We also found that existing protected areas of the Atlantic Forest Hotspot have a very limited capacity to safeguard snakes at the current time, maintaining the precarious protection in the future, with the majority of them predicted to lose species at the end of this century. Although oviparous and viviparous snakes have been designated to be dramatically impacted, our study suggests a greater fragility of the former in the face of climate change. We advocated that the creation of new protected areas and/or the redesign of the existing network to harbour regions that maximize the snake species occupancy in the face of future warming scenarios are crucial measures for the conservation of this group.
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Bacigalupe LD, Vásquez IA, Estay SA, Valenzuela‐Sánchez A, Alvarado‐Rybak M, Peñafiel‐Ricaurte A, Cunningham AA, Soto‐Azat C. The amphibian‐killing fungus in a biodiversity hotspot: identifying and validating high‐risk areas and refugia. Ecosphere 2019. [DOI: 10.1002/ecs2.2724] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Leonardo D. Bacigalupe
- Facultad de Ciencias Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia Chile
| | - Inao A. Vásquez
- Facultad de Ciencias Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia Chile
| | - Sergio A. Estay
- Facultad de Ciencias Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia Chile
- Center of Applied Ecology and Sustainability Pontificia Universidad Católica de Chile Santiago Chile
| | - Andrés Valenzuela‐Sánchez
- Facultad de Ciencias Instituto de Ciencias Ambientales y Evolutivas Universidad Austral de Chile Valdivia Chile
- ONG Ranita de Darwin Santiago Chile
| | - Mario Alvarado‐Rybak
- Centro de Investigación para la Sustentabilidad Facultad de Ciencias de la Vida & Doctorado en Medicina de la Conservación Universidad Andrés Bello Santiago Chile
- Institute of Zoology Zoological Society of London Regent's Park London NW1 4RY UK
| | - Alexandra Peñafiel‐Ricaurte
- Centro de Investigación para la Sustentabilidad Facultad de Ciencias de la Vida & Doctorado en Medicina de la Conservación Universidad Andrés Bello Santiago Chile
- Institute of Zoology Zoological Society of London Regent's Park London NW1 4RY UK
| | - Andrew A. Cunningham
- Institute of Zoology Zoological Society of London Regent's Park London NW1 4RY UK
| | - Claudio Soto‐Azat
- Centro de Investigación para la Sustentabilidad Facultad de Ciencias de la Vida & Doctorado en Medicina de la Conservación Universidad Andrés Bello Santiago Chile
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Puschendorf R, Wallace M, Chavarría MM, Crawford AJ, Wynne F, Knight M, Janzen DH, Hallwachs W, Palmer C, Price SJ. Cryptic diversity and ranavirus infection of a critically endangered Neotropical frog before and after population collapse. Anim Conserv 2019. [DOI: 10.1111/acv.12498] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- R. Puschendorf
- School of Biological and Marine Sciences University of Plymouth Devon UK
| | - M. Wallace
- Department of Zoology University of Oxford Oxford UK
| | - M. M. Chavarría
- Programa de Investigación Área de Conservación Guanacaste Liberia Costa Rica
| | - A. J. Crawford
- Departamento de Ciencias Biológicas Universidad de los Andes Bogotá Colombia
| | - F. Wynne
- School of Biological and Marine Sciences University of Plymouth Devon UK
| | - M. Knight
- School of Biological and Marine Sciences University of Plymouth Devon UK
| | - D. H. Janzen
- Department of Biology University of Pennsylvania Philadelphia PA USA
| | - W. Hallwachs
- Department of Biology University of Pennsylvania Philadelphia PA USA
| | - C.V. Palmer
- School of Biological and Marine Sciences University of Plymouth Devon UK
| | - S. J. Price
- UCL Genetics Institute London UK
- Institute of Zoology, ZSL London UK
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Zumbado‐Ulate H, García‐Rodríguez A, Vredenburg VT, Searle C. Infection with Batrachochytrium dendrobatidis is common in tropical lowland habitats: Implications for amphibian conservation. Ecol Evol 2019; 9:4917-4930. [PMID: 31031954 PMCID: PMC6476760 DOI: 10.1002/ece3.5098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 02/25/2019] [Accepted: 02/28/2019] [Indexed: 11/24/2022] Open
Abstract
Numerous species of amphibians declined in Central America during the 1980s and 1990s. These declines mostly affected highland stream amphibians and have been primarily linked to chytridiomycosis, a deadly disease caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Since then, the majority of field studies on Bd in the Tropics have been conducted in midland and highland environments (>800 m) mainly because the environmental conditions of mountain ranges match the range of ideal abiotic conditions for Bd in the laboratory. This unbalanced sampling has led researchers to largely overlook host-pathogen dynamics in lowlands, where other amphibian species declined during the same period. We conducted a survey testing for Bd in 47 species (n = 348) in four lowland sites in Costa Rica to identify local host-pathogen dynamics and to describe the abiotic environment of these sites. We detected Bd in three sampling sites and 70% of the surveyed species. We found evidence that lowland study sites exhibit enzootic dynamics with low infection intensity and moderate to high prevalence (55% overall prevalence). Additionally, we found evidence that every study site represents an independent climatic zone, where local climatic differences may explain variations in Bd disease dynamics. We recommend more detection surveys across lowlands and other sites that have been historically considered unsuitable for Bd occurrence. These data can be used to identify sites for potential disease outbreaks and amphibian rediscoveries.
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Affiliation(s)
| | - Adrián García‐Rodríguez
- Departamento de Zoología, Instituto de BiologíaUniversidad Nacional Autónoma de México (UNAM)Ciudad de MéxicoMéxico
- Escuela de BiologíaUniversidad de Costa RicaSan JoséCosta Rica
- Departamento de EcologiaUniversidade Federal do Rio Grande do NorteNatalBrazil
| | | | - Catherine Searle
- Department of Biological SciencesPurdue UniversityWest LafayetteIndiana
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Andrew C, Diez J, James TY, Kauserud H. Fungarium specimens: a largely untapped source in global change biology and beyond. Philos Trans R Soc Lond B Biol Sci 2018; 374:20170392. [PMID: 30455210 PMCID: PMC6282084 DOI: 10.1098/rstb.2017.0392] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2018] [Indexed: 11/12/2022] Open
Abstract
For several hundred years, millions of fungal sporocarps have been collected and deposited in worldwide collections (fungaria) to support fungal taxonomy. Owing to large-scale digitization programs, metadata associated with the records are now becoming publicly available, including information on taxonomy, sampling location, collection date and habitat/substrate information. This metadata, as well as data extracted from the physical fungarium specimens themselves, such as DNA sequences and biochemical characteristics, provide a rich source of information not only for taxonomy but also for other lines of biological inquiry. Here, we highlight and discuss how this information can be used to investigate emerging topics in fungal global change biology and beyond. Fungarium data are a prime source of knowledge on fungal distributions and richness patterns, and for assessing red-listed and invasive species. Information on collection dates has been used to investigate shifts in fungal distributions as well as phenology of sporocarp emergence in response to climate change. In addition to providing material for taxonomy and systematics, DNA sequences derived from the physical specimens provide information about fungal demography, dispersal patterns, and are emerging as a source of genomic data. As DNA analysis technologies develop further, the importance of fungarium specimens as easily accessible sources of information will likely continue to grow.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.
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Affiliation(s)
- Carrie Andrew
- Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
| | - Jeffrey Diez
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Håvard Kauserud
- Section for Genetics and Evolutionary Biology (EVOGENE), Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
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Thorpe CJ, Lewis TR, Fisher MC, Wierzbicki CJ, Kulkarni S, Pryce D, Davies L, Watve A, Knight ME. Climate structuring of Batrachochytrium dendrobatidis infection in the threatened amphibians of the northern Western Ghats, India. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180211. [PMID: 30110422 PMCID: PMC6030269 DOI: 10.1098/rsos.180211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 05/04/2018] [Indexed: 05/08/2023]
Abstract
Batrachochytrium dendrobatidis (Bd) is a pathogen killing amphibians worldwide. Its impact across much of Asia is poorly characterized. This study systematically surveyed amphibians for Bd across rocky plateaus in the northern section of the Western Ghats biodiversity hotspot, India, including the first surveys of the plateaus in the coastal region. These ecosystems offer an epidemiological model system since they are characterized by differing levels of connectivity, edaphic and climatic conditions, and anthropogenic stressors. One hundred and eighteen individuals of 21 species of Anura and Apoda on 13 plateaus ranging from 67 to 1179 m above sea level and 15.89 to 17.92° North latitude were sampled. Using qPCR protocols, 79% of species and 27% of individuals tested were positive for Bd. This is the first record of Bd in caecilians in India, the Critically Endangered Xanthophryne tigerina and Endangered Fejervarya cf. sahyadris. Mean site prevalence was 28.15%. Prevalence below the escarpment was 31.2% and 25.4% above. The intensity of infection (GE) showed the reverse pattern. Infection may be related to elevational temperature changes, thermal exclusion, inter-site connectivity and anthropogenic disturbance. Coastal plateaus may be thermal refuges from Bd. Infected amphibians represented a wide range of ecological traits posing interesting questions about transmission routes.
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Affiliation(s)
- Christopher J. Thorpe
- Ecology, Behaviour and Evolution Research Group, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, UK
| | - Todd R. Lewis
- Westfield, 4 Worgret Road, Wareham, Dorset BH20 4PJ, UK
| | - Matthew C. Fisher
- Department of Infectious Disease Epidemiology, Imperial College London, London W2 1PG, UK
| | - Claudia J. Wierzbicki
- Department of Infectious Disease Epidemiology, Imperial College London, London W2 1PG, UK
| | - Siddharth Kulkarni
- Department of Biological Sciences, George Washington University, 2121 I St NW, Washington, DC 20052, USA
| | - David Pryce
- Ecology, Behaviour and Evolution Research Group, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, UK
| | - Lewis Davies
- Ecology, Behaviour and Evolution Research Group, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, UK
| | - Aparna Watve
- Tata Institute of Social Sciences, Apsinga Road, PO Box No. 09, Tuljapur 413 601, District-Osmanabad, Maharashtra, India
| | - Mairi E. Knight
- Ecology, Behaviour and Evolution Research Group, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, UK
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Affiliation(s)
- Thomas R. Raffel
- Department of Biological Sciences Oakland University Rochester MI USA
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42
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Yap TA, Koo MS, Ambrose RF, Vredenburg VT. Introduced bullfrog facilitates pathogen invasion in the western United States. PLoS One 2018; 13:e0188384. [PMID: 29659568 PMCID: PMC5901863 DOI: 10.1371/journal.pone.0188384] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 11/06/2017] [Indexed: 11/22/2022] Open
Abstract
Batrachochytrium dendrobatidis (Bd), a causal agent of the amphibian fungal skin disease chytridiomycosis, has been implicated in the decline and extinction of over 200 species worldwide since the 1970s. Despite almost two decades of research, the history of Bd and its global spread is not well understood. However, the spread of the Global Panzootic Lineage of Bd (Bd-GPL), the lineage associated with amphibian die-offs, has been linked with the American bullfrog (Rana [Aqurana] catesbeiana) and global trade. Interestingly, R. catesbeiana is native to the eastern U.S., where no Bd-related declines have been observed despite Bd’s presence since the late 1800s. In contrast Bd has been found to have emerged in California and Mexico in the 1960s and 1970s, after which epizootics (i.e., epidemics in wildlife) ensued. We hypothesize that Bd-GPL spread from the eastern U.S. with the introduction of R. catesbeiana into the western US, resulting in epizootics and declines of native host species. Using museum records, we investigated the historical relationship between R. catesbeiana and Bd invasion in the western US and found that R. catesbeiana arrived in the same year or prior to Bd in most western watersheds that had data for both species, suggesting that Bd-GPL may have originated in the eastern US and R. catesbeiana may have facilitated Bd invasion in the western US. To predict areas with greatest suitability for Bd, we created a suitability model by integrating habitat suitability and host availability. When we incorporated invasion history with high Bd suitability, we found that watersheds with non-native R. catesbeiana in the mountain ranges of the West Coast have the highest disease risk. These findings shed light on the invasion history and disease dynamics of Bd in North America. Targeted historical surveys using archived specimens in natural history collections and present-day field surveys along with more localized, community-level studies, monitoring, and surveillance are needed to further test this hypothesis and grow our understanding of the disease ecology and host-pathogen dynamics of Bd.
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Affiliation(s)
- Tiffany A. Yap
- Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Michelle S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
| | - Richard F. Ambrose
- Institute of the Environment and Sustainability, University of California, Los Angeles, California, United States of America
- Department of Environmental Health Sciences, University of California, Los Angeles, California, United States of America
| | - Vance T. Vredenburg
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- * E-mail:
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Sonn JM, Berman S, Richards-Zawacki CL. The Influence of Temperature on Chytridiomycosis In Vivo. ECOHEALTH 2017; 14:762-770. [PMID: 28879516 DOI: 10.1007/s10393-017-1269-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 06/23/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
Chytridiomycosis, an amphibian disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is an ideal system for studying the influence of temperature on host-pathogen relationships because both host and pathogen are ectothermic. Studies of Bd in culture suggest that optimal growth occurs between 17 and 23°C, and death of the fungus occurs above 29 or below 0°C. Amphibian immune systems, however, are also temperature dependent and often more effective at higher temperatures. We therefore hypothesized that pathogen load, probability of infection and mortality in Bd-exposed frogs would peak at a lower temperature than that at which Bd grows best in vitro. To test this, we conducted a study where Bd- and sham-exposed Northern cricket frogs (Acris crepitans) were incubated at six temperatures between 11 and 26°C. While probability of infection did not differ across temperatures, pathogen load and mortality were inversely related to temperature. Survival of infected hosts was greatest between 20 and 26°C, temperatures where Bd grows well in culture. These results demonstrate that the conditions under which a pathogen grows best in culture do not necessarily reflect patterns of pathogenicity, an important consideration for predicting the threat of this and other wildlife pathogens.
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Affiliation(s)
- Julia M Sonn
- Department of Ecology and Evolutionary Biology, Tulane University, 400 Lindy Boggs Bldg., New Orleans, LA, 70118, USA.
| | - Scott Berman
- Department of Ecology and Evolutionary Biology, Tulane University, 400 Lindy Boggs Bldg., New Orleans, LA, 70118, USA
| | - Corinne L Richards-Zawacki
- Department of Ecology and Evolutionary Biology, Tulane University, 400 Lindy Boggs Bldg., New Orleans, LA, 70118, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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Clulow S, Gould J, James H, Stockwell M, Clulow J, Mahony M. Elevated salinity blocks pathogen transmission and improves host survival from the global amphibian chytrid pandemic: Implications for translocations. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.13030] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Simon Clulow
- School of Environmental and Life Sciences; University of Newcastle; Callaghan NSW Australia
| | - John Gould
- School of Environmental and Life Sciences; University of Newcastle; Callaghan NSW Australia
| | - Hugh James
- School of Environmental and Life Sciences; University of Newcastle; Callaghan NSW Australia
| | - Michelle Stockwell
- School of Environmental and Life Sciences; University of Newcastle; Callaghan NSW Australia
| | - John Clulow
- School of Environmental and Life Sciences; University of Newcastle; Callaghan NSW Australia
| | - Michael Mahony
- School of Environmental and Life Sciences; University of Newcastle; Callaghan NSW Australia
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Scheele BC, Skerratt LF, Hunter DA, Banks SC, Pierson JC, Driscoll DA, Byrne PG, Berger L. Disease-associated change in an amphibian life-history trait. Oecologia 2017; 184:825-833. [DOI: 10.1007/s00442-017-3911-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 07/06/2017] [Indexed: 11/30/2022]
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Flechas SV, Paz A, Crawford AJ, Sarmiento C, Acevedo AA, Arboleda A, Bolívar-García W, Echeverry-Sandoval CL, Franco R, Mojica C, Muñoz A, Palacios-Rodríguez P, Posso-Terranova AM, Quintero-Marín P, Rueda-Solano LA, Castro-Herrera F, Amézquita A. Current and predicted distribution of the pathogenic fungusBatrachochytrium dendrobatidisin Colombia, a hotspot of amphibian biodiversity. Biotropica 2017. [DOI: 10.1111/btp.12457] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Sandra V. Flechas
- Department of Biological Sciences; Universidad de los Andes; Bogotá AA 4976 Colombia
| | - Andrea Paz
- Department of Biological Sciences; Universidad de los Andes; Bogotá AA 4976 Colombia
- Department of Biology; Graduate Center; City University of New York; New York NY 10016 USA
| | - Andrew J. Crawford
- Department of Biological Sciences; Universidad de los Andes; Bogotá AA 4976 Colombia
- Smithsonian Tropical Research Institute; Apartado 0843-03092 Panama City Republic of Panama
- Círculo Herpetológico de Panamá; Apartado 0824-00122 Panama City Republic of Panama
| | - Carolina Sarmiento
- Department of Biological Sciences; Universidad de los Andes; Bogotá AA 4976 Colombia
- Smithsonian Tropical Research Institute; Apartado 0843-03092 Panama City Republic of Panama
| | - Aldemar A. Acevedo
- Grupo de Investigación en Ecología y Biogeografía (GIEB); Universidad de Pamplona; Pamplona Colombia
| | | | | | | | - Rosmery Franco
- Grupo de Investigación en Ecología y Biogeografía (GIEB); Universidad de Pamplona; Pamplona Colombia
| | - Cindy Mojica
- Grupo de Investigación en Ecología Animal; Universidad del Valle; Cali Colombia
| | | | - Pablo Palacios-Rodríguez
- Department of Biological Sciences; Universidad de los Andes; Bogotá AA 4976 Colombia
- Universidad Tecnológica del Chocó ‘Diego Luis Córdoba’; Quibdó Colombia
| | | | | | | | - Fernando Castro-Herrera
- Departamento de Ciencias Fisiológicas; Facultad de Salud; Universidad del Valle; Cali Colombia
| | - Adolfo Amézquita
- Department of Biological Sciences; Universidad de los Andes; Bogotá AA 4976 Colombia
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Jaeger JR, Waddle AW, Rivera R, Harrison DT, Ellison S, Forrest MJ, Vredenburg VT, van Breukelen F. Batrachochytrium dendrobatidis and the Decline and Survival of the Relict Leopard Frog. ECOHEALTH 2017; 14:285-295. [PMID: 28439781 DOI: 10.1007/s10393-017-1240-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 06/07/2023]
Abstract
Epizootic disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is a major driver of amphibian declines, yet many amphibians declined before the pathogen was described. The Relict Leopard Frog, Rana onca (=Lithobates onca), was nearly extinct, with the exception of populations within a few geothermal springs. Growth of Bd, however, is limited by high water temperature, and geothermal springs may have provided refuge during outbreaks of chytridiomycosis. We conducted field surveys and laboratory experiments to assess the susceptibility of R. onca to Bd. In the field, we found Bd at one of the two areas where remnant populations of R. onca still occur, but not in the other. In the laboratory, we infected juvenile frogs from these two areas with two hypervirulent Bd isolates associated with declines in other ranid species. In our experiments, these Bd isolates did not affect survivorship of R. onca and most infections (64%) were cleared by the end of the experiments. We propose that R. onca either has inherent resistance to Bd or has recently evolved such resistance. These results may be important for conservation efforts aimed at establishing new populations of R. onca across a landscape where Bd exists. Resistance, however, varies among life stages, and we also did not assess Bd from the local environment. We caution that the resistance we observed for young frogs under laboratory conditions may not translate to the situation for R. onca in the wild.
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Affiliation(s)
- Jef R Jaeger
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA.
| | - Anthony W Waddle
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
| | - Rebeca Rivera
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
| | - D Tyler Harrison
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
| | - Silas Ellison
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, USA
| | | | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, USA
| | - Frank van Breukelen
- School of Life Sciences, University of Nevada, Las Vegas, 4505 South Maryland Parkway, Box 454004, Las Vegas, NV, 89154-4004, USA
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Lampo M, Señaris C, García CZ. Population dynamics of the critically endangered toad Atelopus cruciger and the fungal disease chytridiomycosis. PLoS One 2017; 12:e0179007. [PMID: 28570689 PMCID: PMC5453621 DOI: 10.1371/journal.pone.0179007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/22/2017] [Indexed: 11/29/2022] Open
Abstract
Harlequin toads (Atelopus) are among the most severely impacted amphibians by the emergence of chytridiomycosis, a fungal disease caused by the pathogen Batrachochytrium dendrobatidis (Bd). Many species disappeared while others suffered drastic contractions of their geographic distribution to lower altitudes. A diminished virulence of Bd in warm habitats was proposed to explain the survival of lowland populations of harlequin toads (i.e. thermal refuge hypothesis). To understand the mechanisms that allow some populations to reach an endemic equilibrium with this pathogen, we estimated demographic and epidemiological parameters at one remnant population of Atelopus cruciger in Venezuela using mark-recapture data from 2007–2013. We demonstrated that Bd is highly virulent for A. cruciger, increasing the odds of dying of infected adults four times in relation to uninfected ones and reducing the life expectancy of reproductive toads to a few weeks. Despite an estimated annual loss of 18% of the reproductive population due to Bd-induced mortality, this population has persisted in an endemic equilibrium for the last decade through the large recruitment of healthy adults every year. Given the high vulnerability of harlequin toads to Bd in lowland populations, thermal refuges need to be redefined as habitats of reduced transmission rather than attenuated virulence.
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Affiliation(s)
- Margarita Lampo
- Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Kilómetro 11 Carretera Panamericana, Caracas, Venezuela
- * E-mail:
| | - Celsa Señaris
- Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Kilómetro 11 Carretera Panamericana, Caracas, Venezuela
| | - Carmen Zulay García
- Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Kilómetro 11 Carretera Panamericana, Caracas, Venezuela
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Ashiagbor G, Danquah E. Seasonal habitat use by Elephants ( Loxodonta africana) in the Mole National Park of Ghana. Ecol Evol 2017; 7:3784-3795. [PMID: 28616175 PMCID: PMC5468139 DOI: 10.1002/ece3.2962] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 03/01/2017] [Accepted: 03/07/2017] [Indexed: 11/07/2022] Open
Abstract
To avoid unnecessary waste of limited resources and to help prioritize areas for conservation efforts, this study aimed to provide information on habitat use by elephants between the wet and dry seasons in the Mole National Park (MNP) of Ghana. We compiled coordinates of 516 locations of elephants' encounters, 256 for dry season and 260 for wet season. Using nine predictor variables, we modeled the probability of elephant's distribution in MNP. We threshold the models to "suitable" and "nonsuitable" regions of habitat use using the equal training sensitivity and specificity values of 0.177 and 0.181 for the dry and wet seasons, respectively. Accuracy assessment of our models revealed a sensitivity score of 0.909 and 0.974, and a specificity of 0.579 and 0.753 for the dry and wet seasons, respectively. A TSS of 0.488 was also recorded for the dry season and 0.727 for the wet season indicating a good model agreement. Our model predicts habitat use to be confined to the southern portion of MNP due to elevation difference and a relatively steep slope that separates the northern regions of the park from the south. Regions of habitat use for the wet season were 856 km2 and reduced significantly to 547.68 km2 in the dry season. We observed significant overlap (327.24 km2) in habitat use regions between the wet and dry seasons (Schoener's D = 0.922 and Hellinger's-based I = 0.991). DEM, proximity to waterholes, and saltlicks were identified as the key variables that contributed to the prediction. We recommend construction of temporal camps in regions of habitat use that are far from the headquarters area for effective management of elephants. Also, an increase in water point's density around the headquarters areas and selected dry areas of the park will further decrease elephant's range and hence a relatively less resource use in monitoring and patrols.
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Affiliation(s)
- George Ashiagbor
- Department of Wildlife and Range ManagementKwame Nkrumah University of Science and TechnologyKumasiGhana
| | - Emmanuel Danquah
- Department of Wildlife and Range ManagementKwame Nkrumah University of Science and TechnologyKumasiGhana
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Aguilar GD, Blanchon DJ, Foote H, Pollonais CW, Mosee AN. A performance based consensus approach for predicting spatial extent of the Chinese windmill palm ( Trachycarpus fortunei ) in New Zealand under climate change. ECOL INFORM 2017. [DOI: 10.1016/j.ecoinf.2017.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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