Regional variability in diving physiology and behavior in a widely distributed air-breathing marine predator, the South American sea lion Otaria byronia
Abstract
Our understanding of how air-breathing marine predators cope with environmental variability is limited by our inadequate knowledge of their ecological and physiological parameters. Due to their wide distribution along both coasts of the sub-continent, South American sea lions (Otaria byronia) provide a valuable opportunity to study the behavioral and physiological plasticity of a marine predator in different environments. We measured the oxygen stores and diving behavior of South American sea lions throughout most of its range, allowing us to demonstrate that diving ability and behavior vary across its range. We found no significant differences in mass-specific blood volumes of sea lions among field sites and a negative relationship between mass-specific oxygen storage and size, which suggests that exposure to different habitats and geographical locations better explains oxygen storage capacities and diving capability in South American sea lions than body size alone. The largest animals in our study (individuals from Uruguay) were the most shallow and short duration divers, and had the lowest mass-specific total body oxygen stores, while the deepest and longest duration divers (individuals from Southern Chile) had significantly larger mass-specific oxygen stores, despite being much smaller animals.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2016
- Source ID
- 10.1242/jeb.138677
Entities
People
- Alastair M. M. Baylis
- Daniel P. Costa
- Federico Riet-sapriza
- Jennifer M. Burns
- John P. Y. Arnould
- Luis Huckstadt
- Macarena Santos
- Maritza Sepulveda
- Michael S Tift
- Rachael A. Orben
- Valentina Franco-trecu
Organizations
- Deakin University
- Marine Mammal Commission
- Office of Naval Research
- Oregon State University
- Rufford Foundation
- South Atlantic Environmental Research Institute
- University of Alaska Anchorage
- University of California, San Diego
- University of California, Santa Cruz
- University of Granada Faculty of Sciences
- University of Valparaíso
- University of the Republic