2.5 Statistical analyses
To simplify the comparison of behaviour differences in shallow and deep habitat, the eight identified behaviours were group into three main classes (i.e. Fishing, searching, and resting, Table 1). As the three behaviour variables were expressed as a percentage of the total length of foraging bout, they are not independent (i.e. summed to 1), we used generalised multivariate models within Bayesian framework using the R (Team, 2019) package “brms” (Bürkner, 2017). We also we tested three error distribution families: Beta, Gamma, and Gaussian to account for the potentially non-normal distribution. Difference in energy balance was also tested using Bayesian models.