Demographic consequences of changing body size in a terrestrial salamander

• Published in: Ecology and evolution 2021-01, Vol.11 (1), p.174-185
• Main Authors: Hernández‐Pacheco, Raisa, Plard, Floriane, Grayson, Kristine L., Steiner, Ulrich K.
• Format: Article
• Language: English
• Subjects: amphibian; Amphibians; Animal behavior; Animal reproduction; Bayesian analysis; Body size; Capture-recapture studies; Climate change; Demographics; Demography; elasticity analysis; Endangered & extinct species; Growth rate; integral projection model; Metabolism; Original Research; Parameter estimation; Parameter identification; Parameter uncertainty; Physiology; Plethodon cinereus; Population dynamics; Population growth; Population studies; Projection model; Reptiles & amphibians; Survival; Terrestrial environments
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.6988

Changes in climate can alter individual body size, and the resulting shifts in reproduction and survival are expected to impact population dynamics and viability. However, appropriate methods to account for size‐dependent demographic changes are needed, especially in understudied yet threatened groups such as amphibians. We investigated individual‐ and population‐level demographic effects of changes in body size for a terrestrial salamander using capture–mark–recapture data. For our analysis, we implemented an integral projection model parameterized with capture–recapture likelihood estimates from a Bayesian framework. Our study combines survival and growth data from a single dataset to quantify the influence of size on survival while including different sources of uncertainty around these parameters, demonstrating how selective forces can be studied in populations with limited data and incomplete recaptures. We found a strong dependency of the population growth rate on changes in individual size, mediated by potential changes in selection on mean body size and on maximum body size. Our approach of simultaneous parameter estimation can be extended across taxa to identify eco‐evolutionary mechanisms acting on size‐specific vital rates, and thus shaping population dynamics and viability. Changes in climate can alter individual body size, and the resulting shifts in reproduction and survival are expected to impact population dynamics and viability. To quantify size‐dependent demographics, we used an integral projection model with capture–recapture likelihood estimates in a Bayesian framework. We used data from red‐backed salamanders and quantified a strong dependency of the population growth rate to changes in individual size mediated by potential changes in selection on mean body size and on maximum body size.