Data and code for: Field-based estimation of bone collagen trophic discrimination factors in brown bears

This record contains the data and R code used for the analyses reported in the manuscript “Field-based estimation of bone collagen trophic discrimination factors in brown bears”. The study estimates bone collagen trophic discrimination factors (TDFs) for δ13C and δ15N in free-ranging brown bears (Ursus arctos) from the Shiretoko Peninsula, Hokkaido, Japan. The analysis combines brown bear femoral bone collagen isotope ratios with isotope ratios of major dietary resources, propagates source isotope uncertainty, constructs source isotope convex hulls, estimates the two-dimensional translation between source and consumer isotope spaces, and evaluates TDF recovery using simulation analyses. Files included in this record: est_TDF.RR script used for Bayesian source-model fitting, convex-hull construction, field-based TDF estimation, simulation-based evaluation of TDF recovery, summary-table generation, and figure generation. Data_S1.csvBrown bear femoral bone collagen isotope dataset from the Shiretoko region. The file contains 205 records and 15 columns, including sample metadata, δ13C, δ15N, δ34S, analytical standard deviations, and time-corrected δ13C values used in the analysis. Data_S2.csvStomach-content data for brown bears from the Shiretoko region. The file contains 666 records and 4 columns, including sample metadata and the category for each stomach content. Data_S3.csvPotential food-resource isotope dataset for Shiretoko brown bears. The file contains 249 records and 12 columns, including dietary category, family, scientific name, sampled part, δ13C, δ15N, δ34S, elemental percentages, source publication, and DOI. To reproduce the analyses, download est_TDF.R, Data_S1.csv, Data_S2.csv, and Data_S3.csv, place all four files in the same directory, and run est_TDF.R from that directory.