Combining Data Sources to Understand Drivers of Spotted Salamander (Ambystoma maculatum) Population Abundance

Abstract

Abstract Robust methods for estimating abundance of wetland-breeding amphibian species, such as mark–recapture, are often resource intensive. This limits our ability to study the processes that influence species abundance. Alternatively, more efficient sampling methods, such as indices based on visual encounter surveys (VES) (e.g., egg masses), may be biased by variability in detection probabilities and species biology (e.g., no. of egg masses per female). We combine data sources (i.e., VES and capture–mark–recapture) to provide an efficient technique for monitoring wetland-breeding amphibians. Our study focuses on understanding factors that determine local abundance of Spotted Salamanders, Ambystoma maculatum, in Pennsylvania. We first estimated abundance for a subset of wetlands using single-season, capture–mark–recapture data and then verified egg-mass counts collected from a wider network of wetlands as an unbiased index of abundance. We found a strong correlation between estimated adult abundance and...