“…Two specimens from the pre-1542 time bin, both from the Central Coast region, had values consistent with marine resource use (δ 15 N = 14 and 18‰, δ 13 C = −17 and −12.8‰; hereafter called 'marine bears'), but marine resource use was not apparent in any of the grizzlies collected during the post-1542 time bin, despite a larger sample size with strong coastal representation (see also electronic supplementary material, figure S2). Grizzly bivariate stable isotope signatures differed between the time bins (MRPP, p ca 0.003 and p < 0.0001 for analyses including or excluding the two marine bears), owing to an increase in grizzly δ 15 N values (Mann-Whitney U-tests with and without marine bears: δ 15 N p < 0.005 and < 0.0001, respectively; δ 13 C p > 0.30 and > 0.07), suggesting an increase in carnivory through time and a consistent reliance on terrestrial food. Similarly, we found that δ 15 N values increased through time whether marine bears were included or not (δ 15 N values versus years before present (ybp), Spearman's ρ's = + 0.41 and +0.50, p ca 0.002 and 0.0002, respectively) and that δ 13 C values (Suess corrected) and years before present were related when marine bears were excluded (ρ = +0.34, p = 0.012), but not when marine bears were included (ρ = + 0.26, p = 0.06).…”