Supplementary material from "Contrasting offspring dependence periods and diving development rates in two closely related marine mammal species" ...

• Main Authors: Jouma'a, Joffrey, Orgeret, Florian, Picard, Baptiste, Robinson, Patrick W., Weimerskirch, Henri, Guinet, Christophe, Costa, Daniel P., Beltran, Roxanne S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: The Royal Society 2023
• Subjects: Animal behaviour; Elephant Seals; Mirounga leonina; Southern Elephant Seals
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.6971891; https://rs.figshare.com/collections/Supplementary_material_from_Contrasting_offspring_dependence_periods_and_diving_development_rates_in_two_closely_related_marine_mammal_species_/6971891

Understanding the ontogeny of diving behaviour in marine megafauna is crucial due to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species—northern elephant seals ( Mirounga angustirostris, n = 4) and southern elephant seals ( Mirounga leonina, n = 9) —to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison ...