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Polyphenisms occur when phenotypic plasticity produces morphologically distinct phenotypes from the same genotype. Plasticity is maintained through fitness tradeoffs which are conferred to different phenotypes under specific environmental contexts. Predicting the impacts of contemporary climate change on phenotypic plasticity is critical for climate sensitive animals like amphibians, but elucidating the selective pressures maintaining polyphenisms requires a framework to control for all mechanistic drivers of plasticity. Using a 32-year dataset documenting the larval and adult histories of 717 Arizona tiger salamanders (Ambystoma mavortium nebulosum), we determined how annual variation in climate and density-dependence explained the maintenance of two distinct morphs (terrestrial metamorph vs. aquatic paedomorph) in a high-elevation polyphenism. The effects of climate and conspecific density on morph development was evaluated with piecewise structural equation models (SEM) to tease apart the direct and indirect pathways by which these two mechanisms affect phenotypic plasticity. Climate had a direct effect on morph outcome whereby longer growing seasons favored metamorphic outcomes. Also, climate had indirect effects on morph outcome as mediated through density-dependent effects, such as long overwintering coldspells corresponding to high cannibal densities and light snowpacks corresponding to high larval densities; both of which promoted paedomorphic outcomes. Both climate and density-dependence serve as important proxies for growth and resource limitation, which are important underlying drivers of the phenotypic plasticity in animal polyphenisms. Our findings motivate new studies to determine how contemporary climate change will alter the selective pressures maintaining phenotypic plasticity and polyphenisms. See published manuscript for detailed methods. **README FOR THE CSV DATA FILE (Salamander SEM_Data)** * **Data on the adult and larval histories of 717 salamanders** Unique ID's Unique identifier of individual salamanders based on toe clips or PIT tags Pond Origin Pond of larval development Morph Adult developmental (Meta, Paedo) Morph1 Binary expression of adult morph development (1, 0) Cohort Year of birth Sex Male or Female Age First Repro Age of first known reproduction Max. Age Longevity No. Breeding Years Number of years the animal was observed in a breeding state Larval.Age Age of the larvae when captured (years) Larval.SVL SVL of the larvae when captured (mm) Pond.SVL Average SVL of all larvae in a pond (mm) Relative.SVL SVL of the larvae when captured relative to the SVL of all other larvae in the pond (mm) Larval.Cond Body condition (mass/SVL) of the larvae when captured Larval.Year Year that the larvae was captured * **Environmental conditions experienced by the 717 salamanders during their larval lifetime development** Average.Coldspell.Corrected Average annual coldspell conditions experienced by a salamander during it's larval development Average.Cannibal.Density Average annual cannibal densities experienced by a salamander during it's larval development Average.Larval.Density Average annual larval densities experienced by a salamander during its's larval development Average.GDD.Corrected Average annual number of growing degree days during the summer season experienced by a salamander during it's larval development Average.CumSnow.Corrected Average annual snowpack levels experienced by a salamander during its's larval development
Knowledge graph centered on Data from: Climate mediates the tradeoffs associat with 10 nodes and 42 connections. Top connected: climate change, Ambystoma, phenotypic plasticity, Ambystoma tigrinum, Ambystoma tigrinum nebulosm.
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