Fig 1.
Map representing the location of the colony (black dot), all the annual birds’ trips kept in the analysis as dots (color code per year), the limits of the annually prospected areas (same color code as annual birds’ trips) and of the whole study area (black).
Note that the color code for each year will be kept in other figures.
Table 1.
Annual number of individuals (Nind) tracked during a given number of trips (Ntrip), total number of individuals (Nind total) and trips (Ntrip total) per year, and total number of individuals tracked and trips used for that study after removing incomplete tracks.
Table 2.
Annual mean (± SD) of each foraging parameters: Distances in kilometers, durations in hours, bearing angle between -90° (East) and 90° (West) of the colony.
Fig 2.
Mean sea-ice concentrations over each trip duration in the whole study area (2.1) and in the annually prospected area (2.2), according to the interaction between the time elapsed since the annual peak hatching date and the year (color code per year).
Fig 3.
Results of the repeatability (R ± SE) analysis on the total trip duration (hours), cumulative distance (km), the maximal distance (km), the bearing angle (transformed between 0 and 180°) between the colony and the most distal point of the trip, and the mean sea-ice concentration in the central phase of trip (%).
The large black dots correspond to the results of the adjusted repeatability (models with fixed-effects structure and individual ID as random effect; details of models are given in S3.1-S3.5 Tables in S3 Table in S2 File); the grey squares correspond to the results of the non-adjusted repeatability models using only ID as random effect with no fixed-effect.
Fig 4.
Results of the GLM testing the annual effect of the time elapsed between each trip starting date and the annual peak hatching date (in days) on the NND (log-transformed) in the central phase of trip (mean ± CI, log-scale, Fig 4.1); and GAMM results of the effect of the mean sea-ice concentration on the annually prospected area during two compared trip (%) on the NND in the central phase of trip (back transformed into real scale, Fig 4.2), and effect of the mean sea-ice concentration difference in the annually prospected area between two compared trip (%) on the NND in the central phase of trip (back transformed into real scale, Fig 4.3). On the Fig 4.1, each point corresponds to one trip (see Figs 1 and 2 for annual color code). On the Figs 4.2 and 4.3, one point corresponds to the combination of two trips. A low NND value indicates a high foraging-site fidelity, and inversely a high NND value highlights a low site fidelity.
Table 3.
Linear model results of the effect of the year on the NND in the central phase of trip (log-transformed).