Figure 2. Postreproductively Aged Female Killer Whales Are More Likely to Lead Group Movement Compared to Reproductively Aged Females in Times of Low Salmon Abundance As in Figure 1, leader score is used for visualization (N = 48 females, 307 whale years). Analyses were based on permutation-based binomial regression models that account for repeated measures on individuals, sampling biases, and the impact of group size (see Figure S3). Inset: abundance of Chinook salmon in the study area per year of study, measured as the number of fish caught divided by the total catch for the reference period from 1979 to 1982.