FAS for all populations. Small transparent points represent FAS measurements for individual fish. Large filled points indicate mean ± SEM FAS at each chase temperature. Solid lines and equations represent linear models fitted to describe the relationship between FAS and temperature. Dashed lines indicate FAS = 3 (T_FAS3; Lower Deschutes: 24.4°C, John Day: 24.9°C, North Umpqua: 23.3°C, Siletz: 23.8°C).