Modelling southern elephant seals Mirounga leonina using an individual-based model coupled with a dynamic energy budget

PLoS One. 2018 Mar 29;13(3):e0194950. doi: 10.1371/journal.pone.0194950. eCollection 2018.

Abstract

Higher trophic-level species are an integral component of any marine ecosystem. Despite their importance, methods for representing these species in end-to-end ecosystem models often have limited representation of life histories, energetics and behaviour. We built an individual-based model coupled with a dynamic energy budget for female southern elephant seals Mirounga leonina to demonstrate a method for detailed representation of marine mammals. We aimed to develop a model which could i) simulate energy use and life histories, as well as breeding traits of southern elephant seals in an emergent manner, ii) project a stable population over time, and iii) have realistic population dynamics and structure based on emergent life history features (such as age at first breeding, lifespan, fecundity and (yearling) survival). We evaluated the model's ability to represent a stable population over long time periods (>10 generations), including the sensitivity of the emergent properties to variations in key parameters. Analyses indicated that the model is sensitive to changes in resource availability and energy requirements for the transition from pup to juvenile, and juvenile to adult stage. This was particularly the case for breeding success and yearling survival. This model is suitable for use as a standalone tool for investigating the impacts of changes to behaviour and population responses of southern elephant seals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Energy Metabolism
  • Female
  • Food
  • Male
  • Models, Statistical*
  • Population Dynamics
  • Predatory Behavior
  • Reproduction
  • Seals, Earless / metabolism*
  • Seals, Earless / physiology

Grants and funding

This study was supported by the Australian Government’s Cooperative Research Centres Programme through the Antarctic Climate & Ecosystem Cooperative Research Centre (www.acecrc.org.au), the Institute for Marine and Antarctic Studies (www.imas.utas.edu.au/home), through the Australian Antarctic Science Program (AAS 4347), and through an Australian Government Research Training Program Scholarship. The Australian Antarctic Division (www.antarctica.gov.au) through the Australian National Antarctic Research Expeditions (ANARE) supported this research. The study was carried out at Macquarie Island under ethics approval from the Australian Antarctic Animal Ethics Committee (AAS 2265 and AAS 2794) and the Tasmanian Parks and Wildlife Service. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.