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Park JK, Do Y. Current State of Conservation Physiology for Amphibians: Major Research Topics and Physiological Parameters. Animals (Basel) 2023; 13:3162. [PMID: 37893886 PMCID: PMC10603670 DOI: 10.3390/ani13203162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/07/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Analysis of physiological responses can be used to assess population health, identify threat factors, and understand mechanisms of stress. In addition to this, conservation physiologists have sought to establish potential management strategies for environmental change and evaluate the effectiveness of conservation efforts. From past to present, the field of conservation physiology is developing in an increasingly broader context. In this review, we aim to categorize the topics covered in conservation physiology research on amphibians and present the measured physiological parameters to provide directions for future research on conservation physiology. Physiological responses of amphibians to environmental stressors are the most studied topic, but conservation physiological studies on metamorphosis, habitat loss and fragmentation, climate change, and conservation methods are relatively lacking. A number of physiological indices have been extracted to study amphibian conservation physiology, and the indices have varying strengths of correlation with each subject. Future research directions are suggested to develop a comprehensive monitoring method for amphibians, identify interactions among various stressors, establish physiological mechanisms for environmental factors, and quantify the effects of conservation activities on amphibian physiology.
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Affiliation(s)
| | - Yuno Do
- Department of Biological Sciences, Kongju National University, Gongju 32588, Republic of Korea;
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Villamizar-Gomez A, Wang HH, Peterson MR, Grant WE, Forstner MRJ. Environmental determinants of Batrachochytrium dendrobatidis and the likelihood of further dispersion in the face of climate change in Texas, USA. DISEASES OF AQUATIC ORGANISMS 2021; 146:29-39. [PMID: 34498608 DOI: 10.3354/dao03613] [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] [Indexed: 06/13/2023]
Abstract
One of the major drivers of amphibian population declines is Batrachochytrium dendrobatidis (Bd). We sought to identify the major environmental drivers of Bd prevalence in Texas, USA, by drawing results from museum specimens. We sampled one of the largest museum collections in Texas, the Biodiversity Research and Teaching Collections at Texas A&M University. Our sampling focused on the 9 amphibian species with the widest geographical distribution within the state, where we sub-sampled 30% of each species per decade from 1930 to present via skin swabs, totaling 1501 independent sampling events, and used quantitative real-time PCR (qPCR) to detect pathogen presence. We analyzed several geo-referenced variables describing climatic conditions to identify potential factors influencing the likelihood of presence of Bd using boosted regression trees. Our final model suggests the most influential variables are mean temperature of driest quarter, annual mean temperature, temperature annual range, and mean diurnal range. The most likely suitable range for Bd is currently found in the Blackland Prairie and Cross Timbers ecoregions. Results of our future (to the year 2040) projections suggest that Bd could expand its current distribution. Our model could play an important role when developing an integrated conservation plan through (1) focusing future field work on locations with a high likelihood of presence, (2) assisting in the choice of locations for restoration, and (3) developing future research plans including those necessary for projecting reactions to climate change. Our model also could integrate new presence data of Bd when they become available to enhance prediction precision.
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Hudson MA, Griffiths RA, Martin L, Fenton C, Adams SL, Blackman A, Sulton M, Perkins MW, Lopez J, Garcia G, Tapley B, Young RP, Cunningham AA. Reservoir frogs: seasonality of Batrachochytrium dendrobatidis infection in robber frogs in Dominica and Montserrat. PeerJ 2019; 7:e7021. [PMID: 31231595 PMCID: PMC6573808 DOI: 10.7717/peerj.7021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/25/2019] [Indexed: 11/20/2022] Open
Abstract
Emerging infectious diseases are an increasingly important threat to wildlife conservation, with amphibian chytridiomycosis, caused by Batrachochytrium dendrobatidis, the disease most commonly associated with species declines and extinctions. However, some amphibians can be infected with B. dendrobatidis in the absence of disease and can act as reservoirs of the pathogen. We surveyed robber frogs (Eleutherodactylus spp.), potential B. dendrobatidis reservoir species, at three sites on Montserrat, 2011-2013, and on Dominica in 2014, to identify seasonal patterns in B. dendrobatidis infection prevalence and load (B. dendrobatidis genomic equivalents). On Montserrat there was significant seasonality in B. dendrobatidis prevalence and B. dendrobatidis load, both of which were correlated with temperature but not rainfall. B. dendrobatidis prevalence reached 35% in the cooler, drier months but was repeatedly undetectable during the warmer, wetter months. Also, B. dendrobatidis prevalence significantly decreased from 53.2% when the pathogen emerged on Montserrat in 2009 to a maximum 34.8% by 2011, after which it remained stable. On Dominica, where B. dendrobatidis emerged seven years prior to Montserrat, the same seasonal pattern was recorded but at lower prevalence, possibly indicating long-term decline. Understanding the dynamics of disease threats such as chytridiomycosis is key to planning conservation measures. For example, reintroductions of chytridiomycosis-threatened species could be timed to coincide with periods of low B. dendrobatidis infection risk, increasing potential for reintroduction success.
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Affiliation(s)
- Michael A Hudson
- Zoological Society of London, London, UK.,Durrell Wildlife Conservation Trust, Trinity, Jersey, Channel Islands.,Durrell Insitute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, UK
| | - Richard A Griffiths
- Durrell Insitute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, UK
| | - Lloyd Martin
- Department of Environment, Ministry of Agriculture, Housing, Lands and Environment, Brades, Montserrat, West Indies
| | - Calvin Fenton
- Department of Environment, Ministry of Agriculture, Housing, Lands and Environment, Brades, Montserrat, West Indies
| | | | | | - Machel Sulton
- Forestry, Wildlife and Parks Division, Ministry of Environment, Climate Resilience, Disaster Management and Urban Renewal, Roseau, Commonwealth of Dominica, West Indies
| | | | | | | | | | - Richard P Young
- Durrell Wildlife Conservation Trust, Trinity, Jersey, Channel Islands
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Cohen JM, McMahon TA, Ramsay C, Roznik EA, Sauer EL, Bessler S, Civitello DJ, Delius BK, Halstead N, Knutie SA, Nguyen KH, Ortega N, Sears B, Venesky MD, Young S, Rohr JR. Impacts of thermal mismatches on chytrid fungus
Batrachochytrium dendrobatidis
prevalence are moderated by life stage, body size, elevation and latitude. Ecol Lett 2019; 22:817-825. [DOI: 10.1111/ele.13239] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/04/2018] [Accepted: 12/05/2018] [Indexed: 01/11/2023]
Affiliation(s)
- Jeremy M. Cohen
- Department of Integrative Biology University of South Florida Tampa FL USA
| | | | - Chloe Ramsay
- Department of Integrative Biology University of South Florida Tampa FL USA
| | | | - Erin L. Sauer
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Scott Bessler
- Department of Integrative Biology University of South Florida Tampa FL USA
| | | | - Bryan K. Delius
- Department of Integrative Biology University of South Florida Tampa FL USA
| | | | - Sarah A. Knutie
- Department of Ecology and Evolutionary Biology University of Connecticut Storrs CT USA
| | - Karena H. Nguyen
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Nicole Ortega
- Department of Integrative Biology University of South Florida Tampa FL USA
| | - Brittany Sears
- Department of Biological Sciences University of South Florida St. Petersburg St. Petersburg FL USA
| | | | - Suzanne Young
- Ecole polytechnique fédérale de Lausanne (EPFL) Lausanne Switzerland
| | - Jason R. Rohr
- Department of Integrative Biology University of South Florida Tampa FL USA
- Department of Biological Sciences University of Notre Dame Notre Dame IN USA
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Lister BC, Garcia A. Climate-driven declines in arthropod abundance restructure a rainforest food web. Proc Natl Acad Sci U S A 2018; 115:E10397-E10406. [PMID: 30322922 PMCID: PMC6217376 DOI: 10.1073/pnas.1722477115] [Citation(s) in RCA: 269] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A number of studies indicate that tropical arthropods should be particularly vulnerable to climate warming. If these predictions are realized, climate warming may have a more profound impact on the functioning and diversity of tropical forests than currently anticipated. Although arthropods comprise over two-thirds of terrestrial species, information on their abundance and extinction rates in tropical habitats is severely limited. Here we analyze data on arthropod and insectivore abundances taken between 1976 and 2012 at two midelevation habitats in Puerto Rico's Luquillo rainforest. During this time, mean maximum temperatures have risen by 2.0 °C. Using the same study area and methods employed by Lister in the 1970s, we discovered that the dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps. Analysis of long-term data on canopy arthropods and walking sticks taken as part of the Luquillo Long-Term Ecological Research program revealed sustained declines in abundance over two decades, as well as negative regressions of abundance on mean maximum temperatures. We also document parallel decreases in Luquillo's insectivorous lizards, frogs, and birds. While El Niño/Southern Oscillation influences the abundance of forest arthropods, climate warming is the major driver of reductions in arthropod abundance, indirectly precipitating a bottom-up trophic cascade and consequent collapse of the forest food web.
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Affiliation(s)
- Bradford C Lister
- Department of Biological Sciences, Rensselaer Polytechnic University, Troy, NY 12180;
| | - Andres Garcia
- Estación de Biología Chamela, Instituto de Biología, Universidad Nacional Autónoma de México, 47152 Chamela, Jalisco, Mexico
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Climate change-induced increases in precipitation are reducing the potential for solar ultraviolet radiation to inactivate pathogens in surface waters. Sci Rep 2017; 7:13033. [PMID: 29026153 PMCID: PMC5638896 DOI: 10.1038/s41598-017-13392-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/22/2017] [Indexed: 11/09/2022] Open
Abstract
Climate change is accelerating the release of dissolved organic matter (DOM) to inland and coastal waters through increases in precipitation, thawing of permafrost, and changes in vegetation. Our modeling approach suggests that the selective absorption of ultraviolet radiation (UV) by DOM decreases the valuable ecosystem service wherein sunlight inactivates waterborne pathogens. Here we highlight the sensitivity of waterborne pathogens of humans and wildlife to solar UV, and use the DNA action spectrum to model how differences in water transparency and incident sunlight alter the ability of UV to inactivate waterborne pathogens. A case study demonstrates how heavy precipitation events can reduce the solar inactivation potential in Lake Michigan, which provides drinking water to over 10 million people. These data suggest that widespread increases in DOM and consequent browning of surface waters reduce the potential for solar UV inactivation of pathogens, and increase exposure to infectious diseases in humans and wildlife.
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Ruano-Fajardo G, Toledo LF, Mott T. Jumping into a trap: high prevalence of chytrid fungus in the preferred microhabitats of a bromeliad-specialist frog. DISEASES OF AQUATIC ORGANISMS 2016; 121:223-232. [PMID: 27786160 DOI: 10.3354/dao03045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The chytrid fungus Batrachochytrium dendrobatidis (Bd) has been identified as a major threat to several amphibian populations in tropical forests. Amphibians that inhabit the phytotelmata (water tanks) of bromeliads may be especially at risk of Bd infection since the humid, environmentally buffered microhabitat that they prefer might also be favorable for Bd persistence on the host. To test this hypothesis, we sampled adults and tadpoles of the bromeligenous anuran Phyllodytes edelmoi (endemic to the northern Brazilian Atlantic Forest) from the bromeliad Portea leptantha for Bd, using qPCR. We also analyzed 8 bromeliad characteristics: water tank temperature and pH, canopy closure, tank diameter, number of leaves, bromeliad maximum column depth to store water, bromeliad relative volume, and season. Adult frogs preferentially selected bromeliads with a smaller diameter, more leaves and a relatively higher volume of water. We found that Bd was more prevalent in frogs inhabiting bromeliad phytotelmata with smaller diameters, suggesting that the behavioral preferences of P. edelmoi may be driving Bd infection patterns. Therefore, species such as P. edelmoi will be trapped by their own natural history traits.
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Affiliation(s)
- Gustavo Ruano-Fajardo
- Programa de Pós Graduação em Diversidade Biológica e Conservação nos Trópicos, Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Alagoas, Av. Lourival Melo Mota, s/n, Tabuleiro, 57052-970 Maceió, Alagoas, Brazil
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Holmes I, McLaren K, Wilson B. Niche modeling for management-ready information in little-studied, threatened frog species assemblages. J Nat Conserv 2015. [DOI: 10.1016/j.jnc.2015.08.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Raffel TR, Halstead NT, McMahon TA, Davis AK, Rohr JR. Temperature variability and moisture synergistically interact to exacerbate an epizootic disease. Proc Biol Sci 2015; 282:20142039. [PMID: 25567647 DOI: 10.1098/rspb.2014.2039] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Climate change is altering global patterns of precipitation and temperature variability, with implications for parasitic diseases of humans and wildlife. A recent study confirmed predictions that increased temperature variability could exacerbate disease, because of lags in host acclimation following temperature shifts. However, the generality of these host acclimation effects and the potential for them to interact with other factors have yet to be tested. Here, we report similar effects of host thermal acclimation (constant versus shifted temperatures) on chytridiomycosis in red-spotted newts (Notophthalmus viridescens). Batrachochytrium dendrobatidis (Bd) growth on newts was greater following a shift to a new temperature, relative to newts already acclimated to this temperature (15°C versus 25°C). However, these acclimation effects depended on soil moisture (10, 16 and 21% water) and were only observed at the highest moisture level, which induced greatly increased Bd growth and infection-induced mortality. Acclimation effects were also greater following a decrease rather than an increase in temperature. The results are consistent with previous findings that chytridiomycosis is associated with precipitation, lower temperatures and increased temperature variability. This study highlights host acclimation as a potentially general mediator of climate-disease interactions, and the need to account for context-dependencies when testing for acclimation effects on disease.
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Affiliation(s)
- Thomas R Raffel
- Department of Biology, Oakland University, Rochester, MI, USA
| | - Neal T Halstead
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | | | - Andrew K Davis
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
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