Linking extreme interannual changes in prey availability to foraging behaviour and breeding investment in a marine predator, the macaroni penguin

PLoS One. 2017 Sep 14;12(9):e0184114. doi: 10.1371/journal.pone.0184114. eCollection 2017.

Abstract

Understanding the mechanisms that link prey availability to predator behaviour and population change is central to projecting how a species may respond to future environmental pressures. We documented the behavioural responses and breeding investment of macaroni penguins Eudyptes chrysolophus across five breeding seasons where local prey density changed by five-fold; from very low to highly abundant. When prey availability was low, foraging trips were significantly longer and extended overnight. Birds also foraged farther from the colony, potentially in order to reach more distant foraging grounds and allow for increased search times. These extended foraging trips were also linked to a marked decrease in fledgling weights, most likely associated with reduced rates of provisioning. Furthermore, by comparing our results with previous work on this population, it appears that lowered first-year survival rates associated, at least partially, with fledging masses were also evident for this cohort. This study integrates a unique set of prey density, predator behaviour and predator breeding investment data to highlight a possible behavioural mechanism linking perturbations in prey availability to population demography.

MeSH terms

  • Animals
  • Aquatic Organisms / physiology*
  • Food Chain*
  • Population Dynamics
  • Predatory Behavior / physiology*
  • Sexual Behavior, Animal / physiology*
  • Spheniscidae / physiology*

Grants and funding

This work was supported by National Environmental Research Council, http://www.nerc.ac.uk/, Grant No. NE/I52797/X. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.