Figure 3. Fitted relationships between δ 13C measured in brown bear hair collected in Southcentral Sweden 2006–2020 and the annual number of estimated moose calves from hunter observations after accounting for observer effort (3A) and the annual index of bilberry production (3B). Lines are the fitted relationships from the top model with 95% confidence intervals shaded around the lines. Colored points represent the raw data collected, with darker colors representing earlier years and lighter colors representing later years.
δ 15N values varied annually (Figure 2B) and was best described by the annual proportion of moose in the diet, butδ 15N values were not correlated with indices of moose availability. Instead, variation in δ 15N was best explained by the bilberry production index with a one-year time lag (berry production in t affecting stable isotope values int+1 : Table 1, Figure 4A) while accounting for sex-specific age (Figure 4B).