Foraging behaviour and habitat-use drives niche segregation in sibling seabird species: Niche segregation in giant petrels

To mediate competition, similar sympatric species are assumed to use different resources, or the same but geographically separated resources. The two giant petrels (Macronectes spp.) are intriguing in that they are morphologically similar seabirds with overlapping diets and distributions. To better understand the mechanisms allowing their coexistence, we investigated intra- and interspecific niche segregation at Marion Island (Southern Indian Ocean), one of the few localities where they breed in sympatry. We used GPS tracks from 94 individuals and remote-sensed environmental data to quantify habitat use, combined with blood carbon and nitrogen stable isotope ratios from 90 individuals to characterize their foraging habitat and trophic ecology. Females of both species made distant at-sea foraging trips and fed at a similar trophic level. However, they used distinct pelagic habitats. By contrast, males of both species mainly foraged on or near land, resulting in significant sexual segregation, but high interspecific habitat and diet overlap. However, some males showed flexible behavioural strategies, also making distant, pelagic foraging trips. Using contemporaneous tracking, environmental and stable isotope data we provide a clear example of how sympatric sibling species can be segregated along different foraging behaviour dimensions.

competition, diet, habitat selection, movement, partitioning, stable isotopes

10.1098/rsos.200649

2054-5703

Reisinger, Ryan R.

4eaf9440-48e5-41fa-853f-d46457e5444e

Carpenter-Kling, Tegan

1d35fc56-1e0f-4d27-ab94-41bd2b876a91

Connan, Maëlle

96e55fc2-588e-47ef-87d2-ae8c9a09e529

Cherel, Yves

be0d991b-2bda-418b-9753-bcd637d96f28

Pistorius, Pierre A.

5a585272-2721-45dd-9384-56a05a477b36

9 September 2020

Reisinger, Ryan R.

4eaf9440-48e5-41fa-853f-d46457e5444e

Carpenter-Kling, Tegan

1d35fc56-1e0f-4d27-ab94-41bd2b876a91

Connan, Maëlle

96e55fc2-588e-47ef-87d2-ae8c9a09e529

Cherel, Yves

be0d991b-2bda-418b-9753-bcd637d96f28

Pistorius, Pierre A.

5a585272-2721-45dd-9384-56a05a477b36

Reisinger, Ryan R., Carpenter-Kling, Tegan, Connan, Maëlle, Cherel, Yves and Pistorius, Pierre A. (2020) Foraging behaviour and habitat-use drives niche segregation in sibling seabird species: Niche segregation in giant petrels. Royal Society Open Science, 7 (9), [200649]. (doi:10.1098/rsos.200649).

Record type: Article

Abstract

Text

rsos.200649 - Version of Record

Available under License Creative Commons Attribution.

Download (3MB)

More information

Accepted/In Press date: 17 August 2020

Published date: 9 September 2020

Additional Information: Funding Information: Ethics. Ethics approval was granted by the Nelson Mandela University Research Ethics Committee (A14-SCI-ZOO-012). Fieldwork was permitted by the Prince Edward Islands Management committee. Data accessibility. Data and R scripts supporting this manuscript can be found at https://github.com/ryanreisinger/ giantPetrels (doi:10.5281/zenodo.3984174) [87] and at Dryad Digital Repository (doi:10.5061/dryad.31zcrjdj0) [88]. Authors’ contributions. Conceptualization: R.R.R. and P.A.P.; fieldwork: T.C.-K.; Laboratory work: T.C.-K. and M.C.; analyses: R.R.R., T.C.-K., M.C. and Y.C.; writing—original draft preparation: R.R.R., T.C.-K. and M.C.; writing— review and editing: R.R.R., T.C.-K., M.C., Y.C. and P.A.P. Competing interests. We have no competing interests. Funding. This work was funded by the South African National Research Foundation, under the South African National Antarctic Program (grant no. SNA93071 to P.A.P.) and the South African Network for Coastal and Oceanic Research (grant no. 94916 to R.R.R.). Acknowledgements. We thank the South African Department of Environmental Affairs for logistical support. We are grateful to John Lanham and Ian Newton (University of Cape Town) for the stable isotope analyses and to Jess Berndt and David Green for fieldwork. We appreciate the comments of several reviewers, which improved this paper. Publisher Copyright: © 2020 The Authors. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

Keywords: competition, diet, habitat selection, movement, partitioning, stable isotopes