Marine Biology

, 166:83 | Cite as

High individual flexibility in the foraging behavior of a marine predator, the common murre

  • Julia GulkaEmail author
  • Gail K. Davoren
Original paper


The foraging ecology of breeding seabirds is largely influenced by prey availability and energy demands related to reproduction which, in combination with other factors, can affect resource specialization in space and time. In this study, we combined GPS tracking, dive behavior, and stable isotope ratios of carbon and nitrogen to examine behavioral and dietary flexibility within individuals in a breeding pursuit-diving seabird, the common murre (Uria aalge), on the northeast Newfoundland coast. We examined individual flexibility over 2 years (2016, 2017) during which the timing of arrival and availability of their primary prey, capelin (Mallotus villosus), varied. In both years, we found high within-individual variation in foraging trip and dive characteristics, coupled with low spatial overlap of foraging trips both within and among individuals, indicative of flexible behavior. Concurrently, the isotopic niche of breeding common murres showed a higher degree of dietary consistency, evidenced by similar amounts of variation within and among individuals in stable isotope ratios (δ13C, δ15N). Dietary reconstruction revealed that the proportion of different prey types in the diet varied across individuals, suggesting a degree of dietary flexibility. When capelin (prey) availability was low (in 2017), foraging trips were longer and farther from the colony, maximum dive duration decreased, and the proportion of capelin in the diet decreased. Behavioral flexibility, however, remained similar across both years, regardless of prey availability. Our results suggest that common murres can tolerate and respond to fluctuations in prey availability through flexible foraging strategies. Increased foraging distances during low capelin availability suggest increased energetic costs, and thus, an energetic threshold may be reached above which lower prey availability cannot be tolerated.



Principal funding was provided by Natural Sciences and Engineering Research Council of Canada Discovery (2014-06290) and Ship Time Grants (486208-2016 and 501154-2017 to GKD), along with University of Manitoba Faculty of Science Fieldwork Support Program grants (2016, 2017) to GKD. Additional funding was provided by National Geographic Young Explorers Grant (WW-075ER-17) to JG and by World Wildlife Fund-Canada (G-0618-583-00-D) to GKD. GPS tags were partially funded by Environment and Climate Change Canada. We are indebted to the captain and crew of the Lady Easton for their assistance with fieldwork. Thanks to R. Ronconi for assistance with fieldwork, equipment, data analysis and comments on the manuscript; E. Jenkins, P. Calabria Carvalho, K. Johnson, L. Maynard, and W. Ogloff for assistance with field work; and J. Roth and the rest of the University of Manitoba Stable Isotopes in Ecology Group for guidance and feedback during data analysis. We would also like to thank the reviewers.

Data availability statement

The data sets analyzed during the current study are available from the corresponding author upon reasonable request.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

All applicable international, national, and/or institutional guidelines for the care and use of animals were followed. All procedures performed in studies involving animals were in accordance with the ethical standards of the institution or practice at which studies were conducted.


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Authors and Affiliations

  1. 1.Department of Biological SciencesUniversity of ManitobaWinnipegCanada

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