FIGURES
Fig. 1. Map of the study area located in the South-West Indian Ocean. Panel (b) refers to Mauritius and Reunion Islands with the whales’ locations in orange. Panel (c) to the tagging deployment locations along the west coast of Mauritius. The black dotted lines refer to the Exclusive Economic Zone.
Fig. 2. Locations of the sperm whales during the (a) wet and (b) dry seasons. (c,d) Maps of the bathymetry (expressed in m) and (e,f) the slope (expressed in degrees) over the study area. The utilisation distribution (50% and 90% contours) were superimposed for the wet (left panel) and dry (right panel) seasons. MUS refers to Mauritius Island, REU to Reunion Island and RDG to Rodrigues Island.
Fig. 3 . (a,b) Distance to the tagging site over time for the eight migrant whales tracked in 2014 and 2018. The vertical dotted lines refer to the departure date: 2014-12-25 in (a,c) and 2018-12-15 in (b,d). (c,d) SST extracted at the whale’s locations in 2014 and 2018. (e,f) Box plots of the SST extracted inside the kernel 50% during the wet season in 2014 and 2018.
Fig. 4. Box plots of the six performance metrics calculated for each of the 14 models and for each season. The values of each box plot include the performance metrics of each of the 10 simulation runs.
Fig. 5. Box plots of the six performance metrics calculated for the tuned Random Forest model (RF tuned) and the stacking method for each season. The values of each box plot include the performance metrics of each of the 10 simulation runs.
Fig. 6. Averaged prediction maps of the sperm whales’ probabilities during the (a, b) wet and (c, d) dry seasons calculated from the tuned Random Forest model (a, c) and the stacking method (b, d). 0 indicates a very low probability to see a whale, and 1 a high probability to see a whale.
Fig. 7. Kernel densities of the (a) maximum dive depth and the (b) maximum dive duration according to day (in red) and night (in blue).