Figure 1. Annual mean estimates of diet proportions for three demographic classes of brown bears in Sweden: solitary males (A & D), solitary females (B & E), and females with dependent offspring (C & F). Males are included as one demographic class rather than by age group (subadult vs adult) because sample sizes prevented us from looking at changes in male diet proportions between the two age classes. Panels A-C show proportions of all 5 food sources, whereas panels D-F only include protein rich foods (moose and ants)

Ants and moose were consumed in similar proportions across years (Figure 1 D-E) and there was evidence that the proportion of ants and moose decreased over time (\({\widehat{\beta}}_{\left(\text{Ants.Year}\right)}=\ -0.04,\ SE=0.004;\ {\widehat{\beta}}_{\left(\text{Moose.Year}\right)}=-0.02,\ SE=0.002\ \ \)), while the proportion of bilberry in the diet remained stable or slightly increased over time (\({\widehat{\beta}}_{\left(\text{Bilberry.Year}\right)}=0.01,\ SE=0.005\); Table S1). The beta estimates translate to very small changes in diet, with ants and moose proportions decreasing by a 0.25 and 0.025 of 1% each year, respectively. Meanwhile bilberry increased by 0.01 of 1% each year. Over the 25-year study, for solitary female bears, the estimated mean proportions of ants declined from 4.2% to 3.3%, moose declined from 3.9% to 2.9% and estimated mean proportions of bilberry increased from 52% to 55%.