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Article
Similar foraging energetics of two sympatric albatrosses despite contrasting life histories and wind-mediated foraging strategies
Journal of Experimental Biology
  • Caitlin E. Kroeger, University of California, Santa Cruz
  • Daniel E. Crocker, Sonoma State University
  • Rachael A. Orben, Oregon State University
  • David R. Thompson, National Institute of Water and Atmospheric Research
  • Leigh G. Torres, Oregon State University
  • Paul M. Sagar, National Institute of Water and Atmospheric Research
  • Lisa A. Sztukowski, University of Plymouth
  • Timothy Andriese, San Jose State University
  • Daniel P. Costa, University of California, Santa Cruz
  • Scott A. Shaffer, San Jose State University
Publication Date
12-1-2020
Document Type
Article
DOI
10.1242/jeb.228585
Abstract

Understanding the environmental and behavioral factors that influence how organisms maintain energy balance can inform us about their potential resiliency to rapid environmental changes. Flexibility in maintaining energy balance is particularly important to long-lived, central-place foraging seabirds that are constrained when locating food for offspring in a dynamic ocean environment. To understand the role of environmental interactions, behavioral flexibility and morphological constraints on energy balance, we used doubly labeled water to measure the at-sea daily energy expenditure (DEE) of two sympatrically breeding seabirds, Campbell (Thalassarche impavida) and grey-headed (Thalassarche chrysostoma) albatrosses. We found that species and sexes had similar foraging costs, but DEE varied between years for both species and sexes during early chick rearing in two consecutive seasons. For both species, greater DEE was positively associated with larger proportional mass gain, lower mean wind speeds during water take-offs, greater proportions of strong tailwinds (>12 m s-1), and younger chick age. Greater proportional mass gains were marginally more costly in male albatrosses that already have higher wing loading. DEE was higher during flights with a greater proportion of strong headwinds for grey-headed albatrosses only. Poleward winds are forecasted to intensify over the next century, which may increase DEE for grey-headed albatrosses that heavily use this region during early chick rearing. Female Campbell albatrosses may be negatively affected by forecasted slackening winds at lower latitudes due to an expected greater reliance on less energy efficient sit-and-wait foraging strategies. Behavioral plasticity associated with environmental variation may influence future population responses to climate change of both species.

Funding Number
CO1X0905
Funding Sponsor
American Ornithologists' Union
Keywords
  • Daily energy expenditure,
  • Doubly labeled water,
  • Field metabolic rate,
  • Foraging behavior,
  • GPS tracking,
  • Life history,
  • Seabirds
Citation Information
Caitlin E. Kroeger, Daniel E. Crocker, Rachael A. Orben, David R. Thompson, et al.. "Similar foraging energetics of two sympatric albatrosses despite contrasting life histories and wind-mediated foraging strategies" Journal of Experimental Biology Vol. 223 Iss. 23 (2020)
Available at: http://works.bepress.com/scott_shaffer/85/