Increasing numbers of killer whale individuals use fisheries as feeding opportunities within subantarctic populations

• Main Authors: Amelot, Morgane, Tixier, Paul
• Format: Other/Unknown Material
• Language: unknown
• Published: Deakin University 2021
• Subjects: capture-mark-recapture; depredation; killer whale; Killer Whale; Killer whale
• Online Access: https://research.wur.nl/en/datasets/increasing-numbers-of-killer-whale-individuals-use-fisheries-as-f; https://doi.org/10.6084/m9.figshare.16627156

Jolly-Seber capture-mark-recapture models to estimate Crozet regular and type-D Killer whales populations. All codes are available for the simulation, the real data and the trends analysis (1) Simulation code (codesimul.R) is running alone. (2) Real data code (code_vraidata_revfin.R) makes use of three matrices that change depending on the ecotype: - The Capture History (CH_2106_m.csv, CH_2106_d.csv), rows correspond to individuals and columns to years. For regular killer whales this matrix contains 3 possible observations (observed from the coast, observed depredating, non observed) and 2 observations for Type-D killer whales (observed depredating, non observed) - The Marking status (Mk_2106_m.csv, Mk_2106_d.csv), rows correspond to individuals and columns to years. For both ecotype they contain three possible marking status as described in the ESM. - The maturity status (St_2106_m.csv, St_2106_d.csv), rows correspond to individuals and columns to years. For both ecotype they contain four different states (non identify, new-born, juvenile and adult). Two other matrices are the same for both ecotypes - The standardized effort (Effort_stand_boat.csv) contains the yearly effort divided by the maximum number of photographs taken during the study period. - The state matrix (z_init_cro2705.csv) is used to initiate the state matrix from the models. (3) The trend_test.R file presents the extraction of model outputs (regular killer whales: CrozetFinrevfinfin.Rdata, Type-D killer-whales: DFinrevfinfin.Rdata) and their analysis trough different linear and non linear models.