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.