Sex- and age-specific migratory strategies of blue whales in the northeast Pacific Ocean

• DOI: 10.3389/fmars.2022.944918
• Publication Date: 2022-09-02T10:11:41Z
• Authors: Christina Blevins; Geraldine Busquet...; Mario A. Pardo; Diane Gendron; Jeff K. Jacobsen; Francisco Gómez-Díaz; Héctor Pérez-Puig; Christian Daniel ...; Gisela Heckel; Jorge Urbán R; Lorena Viloria-Gó...; Seth D. Newsome
• Keywords: Baleen

Migration is a complex behavior that has evolved in multiple taxonomic groups as means of accessing productive foraging grounds and environmentally stable areas suitable for reproduction. For migratory whales forage throughout the year because their high energetic demands, changes abundance prey different along route(s) can have serious implications individual fitness population viability. Thus, identifying regions these species use to breed while evaluating plasticity at level provide key information management conservation. Serial isotope analysis whale baleen, continuously growing but metabolically inert tissue, proven useful generating records over several years prior death. We measured carbon ( δ 13 C) nitrogen 15 N) values length baleen plates collected from thirteen blue sex age classes, representing largest collection analyzed date northeast Pacific Ocean. Adult females exhibited relatively seasonal movements between temperate latitude subtropical breeding grounds, although two skipped migration one subsequently moved same ground near Costa Rica Dome, potentially give birth. males movement strategies with most remaining latitudes 3-4 before death, migrated grounds. In contrast, patterns juveniles were erratic. These results are driven by requirements during pregnancy nursing adult females, intra-specific competition among males, inexperience locating juveniles. also describe N recently weaned (<16.5m) reflect switching consumption milk solid food (krill). addition, C data suggest continue stored nutrients (blubber) acquired period long after they weaned. broaden our understanding habitat selection this species, highlight importance critical weaning, indicate Dome an important calving region endangered population.