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dc.contributor.advisorBely, Alexandra Een_US
dc.contributor.authorNovarro, Alexander Josephen_US
dc.date.accessioned2018-07-17T06:09:23Z
dc.date.available2018-07-17T06:09:23Z
dc.date.issued2018en_US
dc.identifierhttps://doi.org/10.13016/M26688N6B
dc.identifier.urihttp://hdl.handle.net/1903/20949
dc.description.abstractUnderstanding species responses to climate change has become a top priority for conservation biologists. Unfortunately, current models often treat species as a single entity, ignoring population-level variation. This approach may result in major oversights when managing widespread species, which generally exhibit physiological variation across their geographic range. The eastern red-backed salamander (Plethodon cinereus) is the most widely distributed Plethodon species, extending farther north than any other lungless salamander. This species’ geographic distribution raises two major questions: How does P. cinereus thrive across a wide range of temperatures, and does it possess thermal adaptations that will buffer the ecological consequences of climate change? To explore these questions, I first examined the effects of elevated temperature on metabolic hormone release rates and physiological performance (i.e., ingestion rate and mass gain) across a latitudinal population gradient. I found that physiological traits and populations differ in their thermal flexibility, and that salamanders from warmer localities are more resilient to elevated temperatures. Second, I performed a study to disentangle the environmental and evolutionary drivers of thermal limits across the geographic range of P. cinereus. I found strong support for evolutionary constraints on lower thermal limits, though there was some degree of plasticity in relation to local environmental temperatures. By contrast, upper thermal limits showed little variation across the species’ geographic range and among clades, and far exceeded survival requirements. Third, I combined laboratory experiments, field observations, and population models to explore the role of behavioral thermoregulation in shaping physiological performance in P. cinereus. I found that individuals are likely to exploit moist conditions at the cost of reduced performance, and that populations living in poor thermal quality habitats have greater thermoregulatory accuracy. Overall, my work demonstrates significant variation in thermal physiology across the geographic range and among lineages of P. cinereus and shows that thermal traits differ in their responsiveness to thermal variability. Together, these results highlight the importance of considering multiple physiological metrics and sampling large geographic areas to understand species’ abundance and distributions, and to assess species’ vulnerability to climate change.en_US
dc.language.isoenen_US
dc.titleThermal Physiology in a Widespread Lungless Salamanderen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentBiologyen_US
dc.subject.pqcontrolledEcologyen_US
dc.subject.pqcontrolledPhysiologyen_US
dc.subject.pqcontrolledConservation biologyen_US
dc.subject.pquncontrolledamphibianen_US
dc.subject.pquncontrolledanimal behavioren_US
dc.subject.pquncontrolledclimate changeen_US
dc.subject.pquncontrolledfield biologyen_US
dc.subject.pquncontrolledorganismal biologyen_US
dc.subject.pquncontrolledphysiological ecologyen_US


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