Table 1.

Comparisons between the median flock virtual vanishing bearings for each stage and their corresponding null expectation. Null expectation was calculated as a track with a mean deviation of 0, and a standard deviation exactly equal to that of each flock for the different stages. We compared a linear mixed model (LMM) with stage, and distance as fixed effects and flock as a random effect to a LMM without stage (maximum-likelihood test: χ2 = 130.8, p < 0.001), then used post hoc Tukey tests for pairwise comparisons between combinations of interest.

stage comparisonestimatez-valueBonferroni corrected p-value
stage 1, null−3.40−0.9291
stage 2, null−1.63−0.4461
stage 4, null−13.5−3.680.0024
stage 6, null24.66.71<0.001
stage 3 release 1, null1.170.3201
stage 3 release 2, null−4.05−1.101
stage 5, null1.880.3641
stage 4, stage 3 release 1−16.8−4.59<0.0001
stage 4, stage 3 release 2−17.3−4.73<0.0001
stage 6, stage 522.75.01<0.0001