2.3 Data analysis
We analyse the effect of sex, season and breeding regions on the monthly home-range sizes, cumulative monthly distances travelled (normal error distribution, identity link function), and percentage of monthly overlap (beta error distribution, identity link function) using generalized linear mixed models (GLMMs; glmmTMB package, Brooks et al., 2017). Sex, season and breeding region were included as fixed factors, while individual identity and year were included as random terms in the models to avoid pseudoreplication.
Models were compared using the Akaike Information Criterion corrected for small sample sizes (AICc; Burnham & Anderson, 2002). The best model was the one with the lowest AICc value. All models with a difference of ΔAICc < 2 were considered alternatives (Burnham & Anderson, 2002). For the best model, homogeneity of variance and normality of residuals was inspected by using the “ggresid” package to check the goodness-of-fit of our best models (Goode and Rey 2019). We estimated the variance explained by the fixed and random factors by using the “performance” package (Lüdecke et al., 2021), while differences between their levels were assessed through Tukey posthoc tests using the “emmeans” package (Lenth, 2022). All tests were two-tailed, statistical significance was set at p < 0.05, and all results were shown as mean ± standard deviation. Results of the Tukey post hoc tests included the marginal means and its standard error. Spatial and statistical analyses were done in R version 4.0.3 (R Core Team 2020).