The role of allochrony in influencing interspecific differences in foraging distribution during the non-breeding season between two congeneric crested penguin species

Cara-Paige Green; Norman Ratcliffe; Thomas Mattern; David Thompson; Mary-Anne Lea; Simon Wotherspoon; Pablo Garcia Borboroglu; Ursula Ellenberg; Kyle W Morrison; Klemens Pütz; Paul M Sagar; Philip J Seddon; Leigh G Torres; Mark A Hindell

doi:10.1371/journal.pone.0262901

The role of allochrony in influencing interspecific differences in foraging distribution during the non-breeding season between two congeneric crested penguin species

PLoS One. 2022 Feb 9;17(2):e0262901. doi: 10.1371/journal.pone.0262901. eCollection 2022.

Authors

Cara-Paige Green¹, Norman Ratcliffe², Thomas Mattern^{3

4

5}, David Thompson⁶, Mary-Anne Lea^{1

7}, Simon Wotherspoon^{1

8}, Pablo Garcia Borboroglu^{3

5

9}, Ursula Ellenberg^{5

10}, Kyle W Morrison⁶, Klemens Pütz¹¹, Paul M Sagar¹², Philip J Seddon⁴, Leigh G Torres¹³, Mark A Hindell^{1

7}

Affiliations

¹ Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia.
² British Antarctic Survey, Cambridge, United Kingdom.
³ New Zealand Penguin Initiative, Dunedin, New Zealand.
⁴ Department of Zoology, University of Otago, Dunedin, New Zealand.
⁵ Global Penguin Society, Puerto Madryn, Chubut, Argentina.
⁶ National Institute of Water and Atmospheric Research Ltd., Hataitai, Wellington, New Zealand.
⁷ Australian Centre for Excellence in Antarctic Science, University of Tasmania, Hobart, Tasmania, Australia.
⁸ Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, Tasmania, Australia.
⁹ Centro para el Estudio de Sistemas Marinos (CESIMAR-CONICET), Puerto Madryn, Chubut, Argentina.
¹⁰ Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, Australia.
¹¹ Antarctic Research Trust, Bremervörde, Germany.
¹² National Institute of Water and Atmospheric Research Ltd., Christchurch, New Zealand.
¹³ Department of Fisheries and Wildlife, Marine Mammal Institute, Oregon State University, Newport, Oregon, United States of America.

Abstract

Mechanisms promoting coexistence between closely related species are fundamental for maintaining species diversity. Mechanisms of niche differentiation include allochrony which offsets the peak timing of resource utilisation between species. Many studies focus on spatial and temporal niche partitioning during the breeding season, few have investigated the role allochrony plays in influencing interspecific segregation of foraging distribution and ecology between congeneric species during the non-breeding season. We investigated the non-breeding migrations of Snares (Eudyptes robustus) and Fiordland penguins (Eudyptes pachyrhynchus), closely related species breeding between 100-350 km apart whose migration phenology differs by two months. Using light geolocation tracking, we examined the degree of overlap given the observed allochrony and a hypothetical scenario where the species commence migration simultaneously. We found that Fiordland penguins migrated to the Sub-Antarctic Frontal Zone and Polar Frontal Zone in the austral autumn whereas Snares penguins disperse westwards staying north of the Sub-Tropical Front in the austral winter. Our results suggest that allochrony is likely to be at the root of segregation because the relative profitability of the different water masses that the penguins forage in changes seasonally which results in the two species utilising different areas over their core non-breeding periods. Furthermore, allochrony reduces relatively higher levels of spatiotemporal overlap during the departure and arrival periods, when the close proximity of the two species' colonies would cause the birds to congregate in similar areas, resulting in high interspecific competition just before the breeding season. Available evidence from other studies suggests that the shift in phenology between these species has arisen from adaptive radiation and phenological matching to the seasonality of local resource availability during the breeding season and reduced competitive overlap over the non-breeding season is likely to be an incidental outcome.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Spheniscidae*

Grants and funding

This work was supported by donations from the Antarctic Research Trust, Global Penguin Society and National Geographic. The funders provided support in the form of salaries and/or by covering the costs of field work for authors KP, PGB and KWM, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the “Authors’ contributions” section. This study forms part of a PhD funded by a British Ornithologists’ Union (BOU) John & Pat Warham Studentship from a bequest left to the BOU by the late John and Pat Warham for the study of Sphenisciform and Procellariiform seabirds by a student from Commonwealth countries.