1
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Waddle AW, Clulow S, Aquilina A, Sauer EL, Kaiser SW, Miller C, Flegg JA, Campbell PT, Gallagher H, Dimovski I, Lambreghts Y, Berger L, Skerratt LF, Shine R. Hotspot shelters stimulate frog resistance to chytridiomycosis. Nature 2024; 631:344-349. [PMID: 38926575 DOI: 10.1038/s41586-024-07582-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 05/17/2024] [Indexed: 06/28/2024]
Abstract
Many threats to biodiversity cannot be eliminated; for example, invasive pathogens may be ubiquitous. Chytridiomycosis is a fungal disease that has spread worldwide, driving at least 90 amphibian species to extinction, and severely affecting hundreds of others1-4. Once the disease spreads to a new environment, it is likely to become a permanent part of that ecosystem. To enable coexistence with chytridiomycosis in the field, we devised an intervention that exploits host defences and pathogen vulnerabilities. Here we show that sunlight-heated artificial refugia attract endangered frogs and enable body temperatures high enough to clear infections, and that having recovered in this way, frogs are subsequently resistant to chytridiomycosis even under cool conditions that are optimal for fungal growth. Our results provide a simple, inexpensive and widely applicable strategy to buffer frogs against chytridiomycosis in nature. The refugia are immediately useful for the endangered species we tested and will have broader utility for amphibian species with similar ecologies. Furthermore, our concept could be applied to other wildlife diseases in which differences in host and pathogen physiologies can be exploited. The refugia are made from cheap and readily available materials and therefore could be rapidly adopted by wildlife managers and the public. In summary, habitat protection alone cannot protect species that are affected by invasive diseases, but simple manipulations to microhabitat structure could spell the difference between the extinction and the persistence of endangered amphibians.
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Affiliation(s)
- Anthony W Waddle
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia.
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia.
- Applied BioSciences, Macquarie University, Sydney, New South Wales, Australia.
| | - Simon Clulow
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Amy Aquilina
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Erin L Sauer
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA
| | - Shannon W Kaiser
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Claire Miller
- School of Mathematics and Statistics, University of Melbourne, Parkville, Victoria, Australia
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Jennifer A Flegg
- School of Mathematics and Statistics, University of Melbourne, Parkville, Victoria, Australia
| | - Patricia T Campbell
- Department of Infectious Diseases, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Harrison Gallagher
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Ivana Dimovski
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Yorick Lambreghts
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
- School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Lee Berger
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia
| | - Lee F Skerratt
- Melbourne Veterinary School, University of Melbourne, Werribee, Victoria, Australia
| | - Richard Shine
- School of Natural Sciences, Macquarie University, Sydney, New South Wales, Australia
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2
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Holmes ML, Shine R, Waddle AW. Spontaneous reoccurrence of Batrachochytrium dendrobatidis infections in Australian green tree frogs (Litoria caerulea) following apparently successful heat therapy: Case report. Vet Res Commun 2024:10.1007/s11259-024-10449-2. [PMID: 38951465 DOI: 10.1007/s11259-024-10449-2] [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: 04/03/2024] [Accepted: 06/23/2024] [Indexed: 07/03/2024]
Abstract
Heat therapy has been reported as a safe, effective, and readily available treatment method for heat-tolerant frogs infected with Batrachochytrium dendrobatidis (Bd). We treated wild-caught Australian green tree frogs (Litoria caerulea) infected with Bd using two periods of elevated ambient room temperature (28.2-30.3 °C for 7 weeks followed by 28.9-34.1 °C for 4 weeks). Frogs exhibited persistent and even increasing infection loads in the first treatment period despite prolonged exposure to elevated temperatures, likely due to the presence of cooler microenvironments within their enclosure (25.5-27.0 °C). All frogs eventually returned negative qPCR tests for Bd at the end of the second treatment period, but detectable infections reoccurred one month after frogs were returned to standard housing temperatures (21.2-28.7 °C). Our findings suggest that elevated ambient temperature alone might not eliminate Bd in vivo but can reduce infections loads such that they are undetectable by qPCR analysis of skin swabs. Additional factors, such as cooler microenvironments within enclosures or relative humidity, may influence the success of heat therapy. We recommend further research into the combined effects of temperature and humidity during heat therapy and emphasize the importance of accurate temperature measurements as well as post-treatment monitoring at Bd-permissive temperatures to confirm successful clearance of infections.
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Affiliation(s)
- Madeleine L Holmes
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia.
| | - Richard Shine
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
| | - Anthony W Waddle
- Applied Biosciences, Macquarie University, Sydney, NSW, Australia
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3
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Sinervo B, Lara Reséndiz RA, Miles DB, Lovich JE, Rosen PC, Gadsden H, Gaytán GC, Tessaro PG, Luja VH, Huey RB, Whipple A, Cordero VS, Rohr JB, Caetano G, Santos JC, Sites JW, Méndez de la Cruz FR. Climate change and collapsing thermal niches of desert reptiles and amphibians: Assisted migration and acclimation rescue from extirpation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168431. [PMID: 37951272 DOI: 10.1016/j.scitotenv.2023.168431] [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: 05/08/2023] [Revised: 10/02/2023] [Accepted: 11/06/2023] [Indexed: 11/13/2023]
Abstract
Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins in the northern hemisphere, because of local extirpations or range shifts or both. We combined museum occurrence records from both the continental U.S. and Mexico with a new eco-physiological model of extinction developed for lizard families of the world to predict the distributions of 30 desert-endemic reptile and amphibian species under climate change scenarios. The model predicts that 38 % of local populations will go extinct in the next 50 years, across all 30 species. However, extinctions may be attenuated in forested sites and by the presence of montane environments in contemporary ranges. Of the 30 species, three were at very high risk of extinction as a result of their thermal limits being exceeded, which illustrates the predictive value of ecophysiological modeling approaches for conservation studies. In tandem with global strategies of limiting CO2 emissions, we propose urgent regional management strategies for existing and new reserves that are targeted at three species: Barred Tiger Salamander (Ambystomatidae: Ambystoma mavortium stebbinsi), Desert Short-horned Lizard (Phrynosomatidae: Phrynosoma ornatissimum), and Morafka's Desert Tortoise (Testudinidae: Gopherus morafkai), which face a high risk of extinction by 2070. These strategies focus on assisted migration and preservation within climatic refugia, such as high-elevation and forested habitats. We forecast where new reserves should be established by merging our model of extinction risk with gap analysis. We also highlight that acclimation (i.e., phenotypic plasticity) could ameliorate risk of extinction but is rarely included in ecophysiological models. We use Ambystoma salamanders to show how acclimation can be incorporated into such models of extinction risk.
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Affiliation(s)
- Barry Sinervo
- The Institute for the Study of the Ecological and Evolutionary Climate Impacts, Department of Ecology and Evolutionary Biology, University of California Santa Cruz, CA 95064, USA
| | - Rafael A Lara Reséndiz
- The Institute for the Study of the Ecological and Evolutionary Climate Impacts, Department of Ecology and Evolutionary Biology, University of California Santa Cruz, CA 95064, USA; Instituto Tecnológico de Sonora, Cd. Obregón, Sonora, Mexico
| | - Donald B Miles
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Jeffrey E Lovich
- U.S. Geological Survey, Southwest Biological Science Center, 2255 North Gemini Drive, MS-9394, Flagstaff, AZ 86001, USA
| | - Philip C Rosen
- School of Natural Resources & the Environment, University of Arizona, Tucson, AZ 85721, USA
| | - Héctor Gadsden
- Instituto de Ecología, A.C.-Centro Regional del Bajío, Avenida Lázaro Cárdenas N(o)253, 61600 Pátzcuaro, Michoacán, Mexico
| | - Gamaliel Casteñada Gaytán
- Facultad en Ciencias Biológicas, Universidad Juárez del Estado de Durango, Gómez Palacio, Durango, Mexico
| | | | - Víctor H Luja
- Coordinación de Investigación y Posgrado, Unidad Académica de Turismo, Universidad Autónoma de Nayarit, Ciudad de la Cultura S/N. C.P., 63000 Tepic, Nayarit, Mexico
| | - Raymond B Huey
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Amy Whipple
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Víctor Sánchez Cordero
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de Mexico, Mexico City, Mexico
| | - Jason B Rohr
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Gabriel Caetano
- The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 849900, Israel
| | - Juan C Santos
- Department of Biological Sciences, St. John's University, Queens, New York, NY 11439, USA
| | - Jack W Sites
- Department of Biology, Brigham Young University, Provo, UT 84602, USA
| | - Fausto R Méndez de la Cruz
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA; Laboratorio de Herpetología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
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4
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Wu NC. Pathogen load predicts host functional disruption: A meta‐analysis of an amphibian fungal panzootic. Funct Ecol 2023. [DOI: 10.1111/1365-2435.14245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Nicholas C. Wu
- Hawkesbury Institute for the Environment Western Sydney University Richmond New South Wales Australia
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5
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Kásler A, Ujszegi J, Holly D, Jaloveczki B, Gál Z, Hettyey A. In vitro thermal tolerance of a hypervirulent lineage of Batrachochytrium dendrobatidis: Growth arrestment by elevated temperature and recovery following thermal treatment. Mycologia 2022; 114:661-669. [PMID: 35666647 DOI: 10.1080/00275514.2022.2065443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Chytridiomycosis, an emerging infectious disease caused by Batrachochytrium dendrobatidis (Bd), poses a serious threat to amphibians. The thermal optimum of Bd is lower than that of most amphibians, providing an opportunity to cure infected individuals with elevated temperature. However, this approach presupposes detailed knowledge about the thermal tolerance of the fungus. To determine the temperature that may effectively reduce infection burdens in vivo, detailed in vitro studies are needed to characterize thermal tolerance of the fungus without complexities introduced by the species-specific characteristics of hosts' immune systems. The aim of our study was to evaluate the thermal tolerance of a hypervirulent isolate of Bd, considering the limits of its thermal tolerance and its capacity to rebound following heat treatment. We incubated Bd cell cultures at five different temperatures (21, 25.5, 27, 29, or 30.5 C) for one of six exposure durations (3, 4, 5, 6, 7, or 8 days) and subsequently counted the number of zoospores to assess the temperature dependence of Bd growth. We observed intensive Bd growth at 21 C. At 25.5 C, the number of zoospores also increased over time, but the curve plateaued at about half of the maximum values observed in the lower temperature treatment. At temperatures of 27 C and above, the fungus showed no measurable growth. However, when we moved the cultures back to 21 C after the elevated temperature treatments, we observed recovery of Bd growth in all cultures previously treated at 27 C. At 29 C, a treatment duration of 8 days was necessary to prevent recovery of Bd growth, and at 30.5 C a treatment duration of 5 days was needed to achieve the same result, revealing that these moderately elevated temperatures applied for only a few days have merely a fungistatic rather than a fungicidal effect under in vitro conditions.
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Affiliation(s)
- Andrea Kásler
- Lendület Evolutionary Ecology Research Group, Centre for Agricultural Research, Plant Protection Institute, Eötvös Loránd Research Network, Nagykovácsi str. 26-30., Budapest 1029, Hungary.,Doctoral School of Biology, Institute of Biology, ELTE Eötvös Loránd University, Budapest 1117, Hungary
| | - János Ujszegi
- Lendület Evolutionary Ecology Research Group, Centre for Agricultural Research, Plant Protection Institute, Eötvös Loránd Research Network, Nagykovácsi str. 26-30., Budapest 1029, Hungary.,Department of Systematic Zoology and Ecology, Eötvös Loránd University, Budapest 1117, Hungary
| | - Dóra Holly
- Lendület Evolutionary Ecology Research Group, Centre for Agricultural Research, Plant Protection Institute, Eötvös Loránd Research Network, Nagykovácsi str. 26-30., Budapest 1029, Hungary.,Doctoral School of Biology, Institute of Biology, ELTE Eötvös Loránd University, Budapest 1117, Hungary
| | - Boglárka Jaloveczki
- Department of Zoology, Centre for Agricultural Research, Plant Protection Institute, Budapest 1029, Hungary
| | - Zoltán Gál
- Institute of Genetics and Biotechnology, Animal Biotechnology Department, Hungarian University of Agriculture and Life Sciences, Gödöllő 2100, Hungary
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Centre for Agricultural Research, Plant Protection Institute, Eötvös Loránd Research Network, Nagykovácsi str. 26-30., Budapest 1029, Hungary.,Department of Ecology, University of Veterinary Medicine, Budapest 1078, Hungary
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6
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Venesky MD, DeMarchi J, Hickerson C, Anthony CD. Does the thermal mismatch hypothesis predict disease outcomes in different morphs of a terrestrial salamander? JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:467-476. [PMID: 35167180 DOI: 10.1002/jez.2581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/23/2021] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
Many aspects of ectotherm physiology are temperature-dependent. The immune system of temperate-dwelling ectothermic host species is no exception and their immune function is often downregulated in cold temperatures. Likewise, species of ectothermic pathogens experience temperature-mediated effects on rates of transmission and/or virulence. Although seemingly straightforward, predicting the outcomes of ectothermic host-pathogen interactions is quite challenging. A recent hypothesis termed the thermal mismatch hypothesis posits that cool-adapted host species should be most susceptible to pathogen infection during warm temperature periods whereas warm-adapted host species should be most susceptible to pathogens during periods of cool temperatures. We explore this hypothesis using two ecologically and physiologically differentiated color morphs of the Eastern Red-backed Salamander (Plethodon cinereus) and a pathogenic chytrid fungus (Batrachochytrium dendrobatidis; hereafter "Bd") using a fully factorial laboratory experiment. At cool temperatures, unstriped salamanders (i.e., those that are tolerant of warm temperatures) had a significantly higher probability of Bd infection compared with cool-tolerant striped salamanders, consistent with the thermal mismatch hypothesis. However, we found no support for this hypothesis when salamanders were exposed to Bd at warm temperatures: the probability of Bd infection in the cool-tolerant striped salamanders was nearly identical in both cool and warm temperatures, opposite the predictions of the thermal mismatch hypothesis. Our results are most consistent with the fact that Bd grows poorly at warm temperatures. Alternatively, our data could indicate that the two color morphs do not differ in their tolerance to warm temperatures but that striped salamanders are more tolerant to cool temperatures than unstriped salamanders.
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Affiliation(s)
- Matthew D Venesky
- Department of Biology, Allegheny College, Meadville, Pennsylvania, USA
| | - Joseph DeMarchi
- Department of Biology, John Carroll University, University Heights, Ohio, USA
| | - Cari Hickerson
- Department of Biology, John Carroll University, University Heights, Ohio, USA
| | - Carl D Anthony
- Department of Biology, John Carroll University, University Heights, Ohio, USA
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7
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McTernan MR, Sears MW. Repeatability of Voluntary Thermal Maximum and Covariance with Water Loss Reveal Potential for Adaptation to Changing Climates. Physiol Biochem Zool 2022; 95:113-121. [PMID: 34986078 DOI: 10.1086/717938] [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] [Indexed: 11/03/2022]
Abstract
AbstractAlthough climate warming poses a grave threat to amphibians, little is known about the capacity of this group to evolve in response to warming. The capacity of key traits to evolve depends on the presence of genetic variation on which selection can act. Here, we use repeatability estimates to estimate the potential upper bounds of heritable genetic variation in voluntary and critical thermal maxima of gray-cheeked salamanders (Plethodon metcalfi). Increases in thermal tolerance may also require concordant increases in resistance to water loss because hotter temperatures incur greater evaporative risk. Therefore, we also tested for a correlation between voluntary thermal maxima and resistance to water loss and conducted an acclimation study to test for covariation between these traits in response to warming. Voluntary thermal maxima exhibited low to moderate levels of repeatability (R=0.32, P=0.045), while critical thermal maxima exhibited no statistically significant repeatability (R=0.10, P=0.57). Voluntary thermal maxima also correlated positively with resistance to water loss (R=0.31, P=0.025) but only when controlling for body mass. Voluntary thermal maxima and resistance to water loss also exhibited different acclimatory responses across control (12°C-18°C) and warm (18°C-24°C) temperature regimes, indicating a potential decoupling of traits in different thermal environments. By addressing the repeatability of thermal tolerance and the potential for covariation with resistance to water loss, we begin to address some of the key requirements of amphibians to evolve in warming climates.
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8
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Hector TE, Sgrò CM, Hall MD. Thermal limits in the face of infectious disease: How important are pathogens? GLOBAL CHANGE BIOLOGY 2021; 27:4469-4480. [PMID: 34170603 DOI: 10.1111/gcb.15761] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 06/13/2023]
Abstract
The frequency and severity of both extreme thermal events and disease outbreaks are predicted to continue to shift as a consequence of global change. As a result, species persistence will likely be increasingly dependent on the interaction between thermal stress and pathogen exposure. Missing from the intersection between studies of infectious disease and thermal ecology, however, is the capacity for pathogen exposure to directly disrupt a host's ability to cope with thermal stress. Common sources of variation in host thermal performance, which are likely to interact with infection, are also often unaccounted for when assessing either the vulnerability of species or the potential for disease spread during extreme thermal events. Here, we describe how infection can directly alter host thermal limits, to a degree that exceeds the level of variation commonly seen across species large geographic distributions and that equals the detrimental impact of other ecologically relevant stressors. We then discuss various sources of heterogeneity within and between populations that are likely to be important in mediating the impact that infection has on variation in host thermal limits. In doing so we highlight how infection is a widespread and important source of variation in host thermal performance, which will have implications for both the persistence and vulnerability of species and the dynamics and transmission of disease in a more thermally extreme world.
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Affiliation(s)
- Tobias E Hector
- School of Biological Sciences, Monash University, Melbourne, Vic., Australia
| | - Carla M Sgrò
- School of Biological Sciences, Monash University, Melbourne, Vic., Australia
| | - Matthew D Hall
- School of Biological Sciences, Monash University, Melbourne, Vic., Australia
- Centre of Geometric Biology, Monash University, Melbourne, Vic., Australia
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9
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Bakewell L, Kelehear C, Graham S. Impacts of temperature on immune performance in a desert anuran (
Anaxyrus punctatus
). J Zool (1987) 2021. [DOI: 10.1111/jzo.12891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Zardi GI, Monsinjon JR, McQuaid CD, Seuront L, Orostica M, Want A, Firth LB, Nicastro KR. Foul-weather friends: Modelling thermal stress mitigation by symbiotic endolithic microbes in a changing environment. GLOBAL CHANGE BIOLOGY 2021; 27:2549-2560. [PMID: 33772983 DOI: 10.1111/gcb.15616] [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] [Received: 10/29/2020] [Revised: 02/17/2021] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
Temperature extremes are predicted to intensify with climate change. These extremes are rapidly emerging as a powerful driver of species distributional changes with the capacity to disrupt the functioning and provision of services of entire ecosystems, particularly when they challenge ecosystem engineers. The subsequent search for a robust framework to forecast the consequences of these changes mostly ignores within-species variation in thermal sensitivity. Such variation can be intrinsic, but can also reflect species interactions. Intertidal mussels are important ecosystem engineers that host symbiotic endoliths in their shells. These endoliths unexpectedly act as conditionally beneficial parasites that enhance the host's resistance to intense heat stress. To understand how this relationship may be altered under environmental change, we examined the conditions under which it becomes advantageous by reducing body temperature. We deployed biomimetic sensors (robomussels), built using shells of mussels (Mytilus galloprovincialis) that were or were not infested by endoliths, at nine European locations spanning a temperature gradient across 22°of latitude (Orkney, Scotland to the Algarve, Portugal). Daily wind speed and solar radiation explained the maximum variation in the difference in temperature between infested and non-infested robomussels; the largest difference occurred under low wind speed and high solar radiation. From the robomussel data, we inferred body temperature differences between infested and non-infested mussels during known heatwaves that induced mass mortality of the mussel Mytilus edulis along the coast of the English Channel in summer 2018 to quantify the thermal advantage of endolith infestation during temperature extremes. Under these conditions, endoliths provided thermal buffering of between 1.7°C and 4.8°C. Our results strongly suggest that sustainability of intertidal mussel beds will increasingly depend on the thermal buffering provided by endoliths. More generally, this work shows that biomimetic models indicate that within-species thermal sensitivity to global warming can be modulated by species interactions, using an intertidal host-symbiont relationship as an example.
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Affiliation(s)
- Gerardo I Zardi
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Jonathan R Monsinjon
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | | | - Laurent Seuront
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
- UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, Lille, France
- Department of Marine Energy and Resources, Tokyo University of Marine Science and Technology, Minato-ku, Japan
| | - Mauricio Orostica
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
| | - Andrew Want
- International Centre for Island Technology, Heriot Watt University Orkney Campus, Stromness, UK
| | - Louise B Firth
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, UK
| | - Katy R Nicastro
- Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
- CCMAR, CIMAR Associated Laboratory, University of Algarve, Faro, Portugal
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11
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Cohen JM, Sauer EL, Santiago O, Spencer S, Rohr JR. Divergent impacts of warming weather on wildlife disease risk across climates. Science 2021; 370:370/6519/eabb1702. [PMID: 33214248 DOI: 10.1126/science.abb1702] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 09/10/2020] [Indexed: 12/31/2022]
Abstract
Disease outbreaks among wildlife have surged in recent decades alongside climate change, although it remains unclear how climate change alters disease dynamics across different geographic regions. We amassed a global, spatiotemporal dataset describing parasite prevalence across 7346 wildlife populations and 2021 host-parasite combinations, compiling local weather and climate records at each location. We found that hosts from cool and warm climates experienced increased disease risk at abnormally warm and cool temperatures, respectively, as predicted by the thermal mismatch hypothesis. This effect was greatest in ectothermic hosts and similar in terrestrial and freshwater systems. Projections based on climate change models indicate that ectothermic wildlife hosts from temperate and tropical zones may experience sharp increases and moderate reductions in disease risk, respectively, though the magnitude of these changes depends on parasite identity.
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Affiliation(s)
- Jeremy M Cohen
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA. .,Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| | - Erin L Sauer
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA.,Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| | - Olivia Santiago
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Samuel Spencer
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - 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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12
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Barrile GM, Chalfoun AD, Walters AW. Infection Status as the Basis for Habitat Choices in a Wild Amphibian. Am Nat 2021; 197:128-137. [PMID: 33417518 DOI: 10.1086/711927] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractAnimals challenged with disease may select specific habitat conditions that help prevent or reduce infection. Whereas preinfection avoidance of habitats with a high risk of disease exposure has been documented in both captive and free-ranging animals, evidence of switching habitats after infection to support the clearing of the infection is limited to laboratory experiments. The extent to which wild animals proximately modify habitat choices in response to infection status thus remains unclear. We investigated preinfection behavioral avoidance and postinfection habitat switching using wild, radio-tracked boreal toads (Anaxyrus boreas boreas) in a population challenged with Batrachochytrium dendrobatidis (Bd), a pathogenic fungus responsible for a catastrophic panzootic affecting hundreds of amphibian species worldwide. Boreal toads did not preemptively avoid microhabitats with conditions conducive to Bd growth. Infected individuals, however, selected warmer, more open habitats, which were associated with elevated body temperature and the subsequent clearing of infection. Our results suggest that disease can comprise an important selective pressure on animal habitat and space use. Habitat selection models, therefore, may be greatly improved by including variables that quantify infection risk and/or the infection status of individuals through time.
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13
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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: 14] [Impact Index Per Article: 4.7] [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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14
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Ohmer MEB, Costantini D, Czirják GÁ, Downs CJ, Ferguson LV, Flies A, Franklin CE, Kayigwe AN, Knutie S, Richards-Zawacki CL, Cramp RL. Applied ecoimmunology: using immunological tools to improve conservation efforts in a changing world. CONSERVATION PHYSIOLOGY 2021; 9:coab074. [PMID: 34512994 PMCID: PMC8422949 DOI: 10.1093/conphys/coab074] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/27/2021] [Accepted: 08/09/2021] [Indexed: 05/11/2023]
Abstract
Ecoimmunology is a rapidly developing field that explores how the environment shapes immune function, which in turn influences host-parasite relationships and disease outcomes. Host immune defence is a key fitness determinant because it underlies the capacity of animals to resist or tolerate potential infections. Importantly, immune function can be suppressed, depressed, reconfigured or stimulated by exposure to rapidly changing environmental drivers like temperature, pollutants and food availability. Thus, hosts may experience trade-offs resulting from altered investment in immune function under environmental stressors. As such, approaches in ecoimmunology can provide powerful tools to assist in the conservation of wildlife. Here, we provide case studies that explore the diverse ways that ecoimmunology can inform and advance conservation efforts, from understanding how Galapagos finches will fare with introduced parasites, to using methods from human oncology to design vaccines against a transmissible cancer in Tasmanian devils. In addition, we discuss the future of ecoimmunology and present 10 questions that can help guide this emerging field to better inform conservation decisions and biodiversity protection. From better linking changes in immune function to disease outcomes under different environmental conditions, to understanding how individual variation contributes to disease dynamics in wild populations, there is immense potential for ecoimmunology to inform the conservation of imperilled hosts in the face of new and re-emerging pathogens, in addition to improving the detection and management of emerging potential zoonoses.
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Affiliation(s)
- Michel E B Ohmer
- Living Earth Collaborative, Washington University in St. Louis, MO 63130, USA
| | - David Costantini
- Unité Physiologie Moléculaire et Adaptation (PhyMA), Muséum National d’Histoire Naturelle, CNRS, 57 Rue Cuvier, CP32, 75005, Paris, France
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Cynthia J Downs
- Department of Environmental Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210, USA
| | - Laura V Ferguson
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Andy Flies
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
| | - Ahab N Kayigwe
- Menzies Institute for Medical Research, University of Tasmania, Tasmania 7001, Australia
| | - Sarah Knutie
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06268, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06268, USA
| | | | - Rebecca L Cramp
- School of Biological Sciences, The University of Queensland, Queensland 4072, Australia
- Corresponding author: School of Biological Sciences, The University of Queensland, Queensland 4072, Australia.
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15
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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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16
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Abstract
Climate change is expected to have complex effects on infectious diseases, causing some to increase, others to decrease, and many to shift their distributions. There have been several important advances in understanding the role of climate and climate change on wildlife and human infectious disease dynamics over the past several years. This essay examines 3 major areas of advancement, which include improvements to mechanistic disease models, investigations into the importance of climate variability to disease dynamics, and understanding the consequences of thermal mismatches between host and parasites. Applying the new information derived from these advances to climate-disease models and addressing the pressing knowledge gaps that we identify should improve the capacity to predict how climate change will affect disease risk for both wildlife and humans.
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Affiliation(s)
- Jason R. Rohr
- Department of Biological Sciences, Environmental Change Initiative, Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Jeremy M. Cohen
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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17
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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: 31] [Impact Index Per Article: 7.8] [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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18
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Beukema W, Pasmans F, Van Praet S, Ferri-Yáñez F, Kelly M, Laking AE, Erens J, Speybroeck J, Verheyen K, Lens L, Martel A. Microclimate limits thermal behaviour favourable to disease control in a nocturnal amphibian. Ecol Lett 2020; 24:27-37. [PMID: 33022129 DOI: 10.1111/ele.13616] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/15/2020] [Accepted: 09/07/2020] [Indexed: 11/28/2022]
Abstract
While epizootics increasingly affect wildlife, it remains poorly understood how the environment shapes most host-pathogen systems. Here, we employ a three-step framework to study microclimate influence on ectotherm host thermal behaviour, focusing on amphibian chytridiomycosis in fire salamanders (Salamandra salamandra) infected with the fungal pathogen Batrachochytrium salamandrivorans (Bsal). Laboratory trials reveal that innate variation in thermal preference, rather than behavioural fever, can inhibit infection and facilitate salamander recovery under humidity-saturated conditions. Yet, a 3-year field study and a mesocosm experiment close to the invasive Bsal range show that microclimate constraints suppress host thermal behaviour favourable to disease control. A final mechanistic model, that estimates range-wide, year-round host body temperature relative to microclimate, suggests that these constraints are rule rather than exception. Our results demonstrate how innate host defences against epizootics may remain constrained in the wild, which predisposes to range-wide disease outbreaks and population declines.
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Affiliation(s)
- Wouter Beukema
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Sarah Van Praet
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Francisco Ferri-Yáñez
- Department of Community Ecology, Helmholtz Centre for Environmental Research (UFZ), Theodor-Lieser-Strasse 4, Halle, 06120, Germany
| | - Moira Kelly
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Alexandra E Laking
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Jesse Erens
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
| | - Jeroen Speybroeck
- Research Institute for Nature and Forest - INBO, Havenlaan 88 bus 73, Brussels, 1000, Belgium
| | - Kris Verheyen
- Forest & Nature Lab, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, Gontrode, 9090, Belgium
| | - Luc Lens
- Terrestrial Ecology Unit, Ghent University, K. L, Ledeganckstraat 35, Ghent, 9000, Belgium
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology and Avian Diseases, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium
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19
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Komaki S, Sutoh Y, Kobayashi K, Saito S, Saito CT, Igawa T, Lau Q. Hot spring frogs ( Buergeria japonica) prefer cooler water to hot water. Ecol Evol 2020; 10:9466-9473. [PMID: 32953075 PMCID: PMC7487256 DOI: 10.1002/ece3.6637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/11/2020] [Accepted: 07/16/2020] [Indexed: 11/06/2022] Open
Abstract
"Hot spring frog" is an informal name used for the Japanese stream tree frog (Buergeria japonica), which is widely distributed in Taiwan and the Ryukyu Archipelago in Japan. Some populations of the species are known to inhabit hot springs. However, water temperature can be extremely high around the sources of hot springs. Thus, it is questionable whether B. japonica selectively inhabits such dangerous environments. To address this question, we conducted a series of observations of water temperature preferences of a hot spring population of B. japonica in Kuchinoshima Island in Japan: (a) a field observation of tadpole density in water pools of different temperatures, (b) a field observation of water temperatures where adult males appear for breeding, and (c) an indoor observation of water temperatures selected by adult females for oviposition. As a result, tadpoles showed a higher density in cooler water. Adult males avoided water pools hotter than 37°C, and adult females selected cooler pools for oviposition. Camera records also showed that adult individuals tend to appear around cooler pools. Thus, we did not find any support for the hypothesis that hot spring frogs prefer hot water. Conversely, they apparently tended to prefer cooler water if it was available. Water temperatures around the sources of the hot spring exceed thermal tolerances of the species and could be a strong selective pressure on the population. Thus, the ability to sense and avoid lethal temperatures may be a key ecological and physiological characteristic for the species that inhabit hot springs.
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Affiliation(s)
- Shohei Komaki
- Division of Biomedical Information AnalysisIwate Tohoku Medical Megabank OrganizationDisaster Reconstruction CenterIwate Medical UniversityYahabaJapan
| | - Yoichi Sutoh
- Division of Biomedical Information AnalysisIwate Tohoku Medical Megabank OrganizationDisaster Reconstruction CenterIwate Medical UniversityYahabaJapan
| | | | - Shigeru Saito
- Division of Cell SignalingNational Institute for Physiological SciencesNational Institutes of Natural SciencesOkazakiJapan
| | - Claire T. Saito
- Division of Cell SignalingNational Institute for Physiological SciencesNational Institutes of Natural SciencesOkazakiJapan
| | - Takeshi Igawa
- Amphibian Research CenterHiroshima UniversityHigashi‐HiroshimaJapan
| | - Quintin Lau
- Department of Evolutionary Studies of BiosystemsSokendai (The Graduate University for Advanced Studies)HayamaJapan
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20
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Zamudio KR, McDonald CA, Belasen AM. High Variability in Infection Mechanisms and Host Responses: A Review of Functional Genomic Studies of Amphibian Chytridiomycosis. HERPETOLOGICA 2020. [DOI: 10.1655/0018-0831-76.2.189] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA
| | - Cait A. McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA
| | - Anat M. Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA
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21
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Pabijan M, Palomar G, Antunes B, Antoł W, Zieliński P, Babik W. Evolutionary principles guiding amphibian conservation. Evol Appl 2020; 13:857-878. [PMID: 32431739 PMCID: PMC7232768 DOI: 10.1111/eva.12940] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 02/05/2020] [Accepted: 02/18/2020] [Indexed: 12/18/2022] Open
Abstract
The Anthropocene has witnessed catastrophic amphibian declines across the globe. A multitude of new, primarily human-induced drivers of decline may lead to extinction, but can also push species onto novel evolutionary trajectories. If these are recognized by amphibian biologists, they can be engaged in conservation actions. Here, we summarize how principles stemming from evolutionary concepts have been applied for conservation purposes, and address emerging ideas at the vanguard of amphibian conservation science. In particular, we examine the consequences of increased drift and inbreeding in small populations and their implications for practical conservation. We then review studies of connectivity between populations at the landscape level, which have emphasized the limiting influence of anthropogenic structures and degraded habitat on genetic cohesion. The rapid pace of environmental changes leads to the central question of whether amphibian populations can cope either by adapting to new conditions or by shifting their ranges. We gloomily conclude that extinction seems far more likely than adaptation or range shifts for most species. That said, conservation strategies employing evolutionary principles, such as selective breeding, introduction of adaptive variants through translocations, ecosystem interventions aimed at decreasing phenotype-environment mismatch, or genetic engineering, may effectively counter amphibian decline in some areas or for some species. The spread of invasive species and infectious diseases has often had disastrous consequences, but has also provided some premier examples of rapid evolution with conservation implications. Much can be done in terms of setting aside valuable amphibian habitat that should encompass both natural and agricultural areas, as well as designing protected areas to maximize the phylogenetic and functional diversity of the amphibian community. We conclude that an explicit consideration and application of evolutionary principles, although certainly not a silver bullet, should increase effectiveness of amphibian conservation in both the short and long term.
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Affiliation(s)
- Maciej Pabijan
- Institute of Zoology and Biomedical ResearchFaculty of BiologyJagiellonian UniversityKrakówPoland
| | - Gemma Palomar
- Institute of Environmental SciencesFaculty of BiologyJagiellonian UniversityKrakówPoland
| | - Bernardo Antunes
- Institute of Environmental SciencesFaculty of BiologyJagiellonian UniversityKrakówPoland
| | - Weronika Antoł
- Institute of Environmental SciencesFaculty of BiologyJagiellonian UniversityKrakówPoland
| | - Piotr Zieliński
- Institute of Environmental SciencesFaculty of BiologyJagiellonian UniversityKrakówPoland
| | - Wiesław Babik
- Institute of Environmental SciencesFaculty of BiologyJagiellonian UniversityKrakówPoland
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22
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Sauer EL, Cohen JM, Lajeunesse MJ, McMahon TA, Civitello DJ, Knutie SA, Nguyen K, Roznik EA, Sears BF, Bessler S, Delius BK, Halstead N, Ortega N, Venesky MD, Young S, Rohr JR. A meta-analysis reveals temperature, dose, life stage, and taxonomy influence host susceptibility to a fungal parasite. Ecology 2020; 101:e02979. [PMID: 31960949 DOI: 10.1002/ecy.2979] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 10/25/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022]
Abstract
Complex ecological relationships, such as host-parasite interactions, are often modeled with laboratory experiments. However, some experimental laboratory conditions, such as temperature or infection dose, are regularly chosen based on convenience or convention, and it is unclear how these decisions systematically affect experimental outcomes. Here, we conducted a meta-analysis of 58 laboratory studies that exposed amphibians to the pathogenic fungus Batrachochytrium dendrobatidis (Bd) to understand better how laboratory temperature, host life stage, infection dose, and host species affect host mortality. We found that host mortality was driven by thermal mismatches: hosts native to cooler environments experienced greater Bd-induced mortality at relatively warm experimental temperatures and vice versa. We also found that Bd dose positively predicted Bd-induced host mortality and that the superfamilies Bufonoidea and Hyloidea were especially susceptible to Bd. Finally, the effect of Bd on host mortality varied across host life stages, with larval amphibians experiencing lower risk of Bd-induced mortality than adults or metamorphs. Metamorphs were especially susceptible and experienced mortality when inoculated with much smaller Bd doses than the average dose used by researchers. Our results suggest that when designing experiments on species interactions, researchers should carefully consider the experimental temperature, inoculum dose, and life stage, and taxonomy of the host species.
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Affiliation(s)
- Erin L Sauer
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA.,Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Dr., Madison, 53706, Wisconsin, USA
| | - Jeremy M Cohen
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA.,Department of Forest and Wildlife Ecology, University of Wisconsin, 1630 Linden Dr., Madison, 53706, Wisconsin, USA
| | - Marc J Lajeunesse
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Taegan A McMahon
- Department of Biology, University of Tampa, 401 W. Kennedy Blvd., Tampa, 33606, Florida, USA
| | - David J Civitello
- Department of Biology, Emory University, 201 Dowman Dr., Atlanta, 30322, Georgia, USA
| | - Sarah A Knutie
- Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road, Storrs, 06269, Connecticut, USA
| | - Karena Nguyen
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Elizabeth A Roznik
- Department of Research and Conservation, Memphis Zoo, 2000 Prentiss Place, Memphis, 38112, Tennessee, USA
| | | | - Scott Bessler
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Bryan K Delius
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Neal Halstead
- Wildlands Conservation, 15310 Amberly Dr., Suite 250, Tampa, 33647, Florida, USA
| | - Nicole Ortega
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA
| | - Matthew D Venesky
- Department of Biology, Allegheny College, 520 N Main St., Meadville, 16335, Pennsylvania, USA
| | - Suzanne Young
- Environmental Engineering Institute, Ecole polytechnique fédérale de Lausanne (EPFL), Route Cantonale, 1015, Lausanne, Switzerland
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, 4202 East Fowler Ave, Tampa, 33620, Florida, USA.,Department of Biological Science, University of Notre Dame, 100 Galvin Life Science Center, Notre Dame, 46656, Indiana, USA
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23
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Ellison A, Zamudio K, Lips K, Muletz‐Wolz C. Temperature‐mediated shifts in salamander transcriptomic responses to the amphibian‐killing fungus. Mol Ecol 2020; 29:325-343. [DOI: 10.1111/mec.15327] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/04/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Amy Ellison
- School of Natural Sciences Bangor University Bangor UK
| | - Kelly Zamudio
- Department of Ecology & Evolutionary Biology Cornell University Ithaca NY USA
| | - Karen Lips
- Department of Biology University of Maryland College Park MD USA
| | - Carly Muletz‐Wolz
- Department of Biology University of Maryland College Park MD USA
- Center for Conservation Genomics Smithsonian Conservation Biology Institute National Zoological Park Washington DC USA
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24
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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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25
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Sauer EL, Trejo N, Hoverman JT, Rohr JR. Behavioural fever reduces ranaviral infection in toads. Funct Ecol 2019; 33:2172-2179. [PMID: 33041425 DOI: 10.1111/1365-2435.13427] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. Host behaviour is known to influence disease dynamics. Additionally, hosts often change their behaviours in response to pathogen detection to resist and avoid disease. The capacity of wildlife populations to respond to pathogens using behavioural plasticity is critical for reducing the impacts of disease outbreaks. However, there is limited information regarding the ability of ectothermic vertebrates to resist diseases via behavioural plasticity. 2. Here, we experimentally examine the effect of host behaviour on ranaviral infections, which affect at least 175 species of ectothermic vertebrates. We placed metamorphic (temporal block 1) or adult (block 2) Southern toads (Anaxyrus terrestris) in thermal gradients, tested their temperature preferences before and after oral inoculation by measuring individual-level body temperature over time, and measured ranaviral loads of viral-exposed individuals. 3. We found significant individual-level variation in temperature preference and evidence for behavioural fever in both metamorph and adult A. terrestris during the first two days after exposure. Additionally, we found that individual-level change in temperature preference was negatively correlated with ranaviral load and a better predictor of load than average temperature preference or maximum temperature reached by an individual. In other words, an increase in baseline temperature preference was more important than simply reaching an absolute temperature. 4. These results suggest that behavioural fever is an effective mechanism for resisting ranaviral infections.
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Affiliation(s)
- Erin L Sauer
- Department of Integrative Biology, University of South Florida, Tampa, FL, U.S.A
| | - Nadia Trejo
- Department of Integrative Biology, University of South Florida, Tampa, FL, U.S.A
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, U.S.A
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL, U.S.A
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26
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Price SJ, Leung WTM, Owen CJ, Puschendorf R, Sergeant C, Cunningham AA, Balloux F, Garner TWJ, Nichols RA. Effects of historic and projected climate change on the range and impacts of an emerging wildlife disease. GLOBAL CHANGE BIOLOGY 2019; 25:2648-2660. [PMID: 31074105 DOI: 10.1111/gcb.14651] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
The global trend of increasing environmental temperatures is often predicted to result in more severe disease epidemics. However, unambiguous evidence that temperature is a driver of epidemics is largely lacking, because it is demanding to demonstrate its role among the complex interactions between hosts, pathogens, and their shared environment. Here, we apply a three-pronged approach to understand the effects of temperature on ranavirus epidemics in UK common frogs, combining in vitro, in vivo, and field studies. Each approach suggests that higher temperatures drive increasing severity of epidemics. In wild populations, ranavirosis incidents were more frequent and more severe at higher temperatures, and their frequency increased through a period of historic warming in the 1990s. Laboratory experiments using cell culture and whole animal models showed that higher temperature increased ranavirus propagation, disease incidence, and mortality rate. These results, combined with climate projections, predict severe ranavirosis outbreaks will occur over wider areas and an extended season, possibly affecting larval recruitment. Since ranaviruses affect a variety of ectothermic hosts (amphibians, reptiles, and fish), wider ecological damage could occur. Our three complementary lines of evidence present a clear case for direct environmental modulation of these epidemics and suggest management options to protect species from disease.
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Affiliation(s)
- Stephen J Price
- UCL Genetics Institute, London, United Kingdom
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - William T M Leung
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | | | - Robert Puschendorf
- School of Biological and Marine Sciences, University of Plymouth, Devon, United Kingdom
| | - Chris Sergeant
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | | | | | - Trenton W J Garner
- Institute of Zoology, Zoological Society of London, London, United Kingdom
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27
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Hettyey A, Ujszegi J, Herczeg D, Holly D, Vörös J, Schmidt BR, Bosch J. Mitigating Disease Impacts in Amphibian Populations: Capitalizing on the Thermal Optimum Mismatch Between a Pathogen and Its Host. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00254] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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28
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Muletz-Wolz CR, Fleischer RC, Lips KR. Fungal disease and temperature alter skin microbiome structure in an experimental salamander system. Mol Ecol 2019; 28:2917-2931. [PMID: 31066947 DOI: 10.1111/mec.15122] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/27/2019] [Accepted: 04/25/2019] [Indexed: 12/29/2022]
Abstract
Pathogens compete with host microbiomes for space and resources. Their shared environment impacts pathogen-microbiome-host interactions, which can lead to variation in disease outcome. The skin microbiome of red-backed salamanders (Plethodon cinereus) can reduce infection by the pathogen Batrachochytrium dendrobatidis (Bd) at moderate infection loads, with high species richness and high abundance of competitors as putative mechanisms. However, it is unclear if the skin microbiome can reduce epizootic Bd loads across temperatures. We conducted a laboratory experiment to quantify skin microbiome and host responses (P. cinereus: n = 87) to Bd at mimicked epizootic loads across temperatures (13, 17 and 21°C). We quantified skin microbiomes using 16S rRNA gene metabarcoding and identified operational taxonomic units (OTUs) taxonomically similar to culturable bacteria known to kill Bd (anti-Bd OTUs). Prior to pathogen exposure, temperature changed the microbiome (OTU richness decreased by 12% and the abundance of anti-Bd OTUs increased by 18% per degree increase in temperature), but these changes were not predictive of disease outcome. After exposure, Bd changed the microbiome (OTU richness decreased by 0.1% and the abundance of anti-Bd OTUs increased by 0.2% per 1% increase in Bd load) and caused high host mortality across temperatures (35/45: 78%). Temperature indirectly impacted microbiome change and mortality through its direct effect on pathogen load. We did not find support for the microbiome impacting Bd load or host survival. Our research reveals complex host, pathogen, microbiome and environmental interactions to demonstrate that during epizootic events the microbiome will be unlikely to reduce pathogen invasion, even for putatively Bd-resistant species.
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Affiliation(s)
- Carly R Muletz-Wolz
- Department of Biology, University of Maryland, College Park, Maryland.,Center for Conservation Genomics, Smithsonian National Zoological Park and Conservation Biology Institute, Washington, District of Columbia
| | - Robert C Fleischer
- Center for Conservation Genomics, Smithsonian National Zoological Park and Conservation Biology Institute, Washington, District of Columbia
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, Maryland
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29
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Gehman AM, Harley CDG. Symbiotic endolithic microbes alter host morphology and reduce host vulnerability to high environmental temperatures. Ecosphere 2019. [DOI: 10.1002/ecs2.2683] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Alyssa‐Lois M. Gehman
- Department of Zoology University of British Columbia Vancouver British Columbia Canada
- Hakai Institute, End of Kwakshua Channel Calvert Island British Columbia Canada
| | - Christopher D. G. Harley
- Department of Zoology University of British Columbia Vancouver British Columbia Canada
- Institute for the Oceans and Fisheries University of British Columbia Vancouver British Columbia Canada
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30
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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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31
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Sauer EL, Fuller RC, Richards-Zawacki CL, Sonn J, Sperry JH, Rohr JR. Variation in individual temperature preferences, not behavioural fever, affects susceptibility to chytridiomycosis in amphibians. Proc Biol Sci 2018; 285:rspb.2018.1111. [PMID: 30135162 DOI: 10.1098/rspb.2018.1111] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/27/2018] [Indexed: 11/12/2022] Open
Abstract
The ability of wildlife populations to mount rapid responses to novel pathogens will be critical for mitigating the impacts of disease outbreaks in a changing climate. Field studies have documented that amphibians preferring warmer temperatures are less likely to be infected with the fungal pathogen Batrachochytrium dendrobatidis (Bd). However, it is unclear whether this phenomenon is driven by behavioural fever or natural variation in thermal preference. Here, we placed frogs in thermal gradients, tested for temperature preferences and measured Bd growth, prevalence, and the survival of infected animals. Although there was significant individual- and species-level variation in temperature preferences, we found no consistent evidence of behavioural fever across five frog species. Interestingly, for species that preferred warmer temperatures, the preferred temperatures of individuals were negatively correlated with Bd growth on hosts, while the opposite correlation was true for species preferring cooler temperatures. Our results suggest that variation in thermal preference, but not behavioural fever, might shape the outcomes of Bd infections for individuals and populations, potentially resulting in selection for individual hosts and host species whose temperature preferences minimize Bd growth and enhance host survival during epidemics.
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Affiliation(s)
- Erin L Sauer
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Rebecca C Fuller
- Department of Animal Biology, University of Illinois, Champaign, IL 61820, USA
| | | | - Julia Sonn
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA 70118, USA
| | - Jinelle H Sperry
- US Army Engineer Research and Development Center, Champaign, IL 61826, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
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