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Proliferation of East Antarctic Adélie penguins in response to historical deglaciation

Citation

Younger, J and Emmerson, L and Southwell, C and Lelliott, P and Miller, K, Proliferation of East Antarctic Adelie penguins in response to historical deglaciation, BMC Evolutionary Biology, 15 Article 236. ISSN 1471-2148 (2015) [Refereed Article]


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Copyright Statement

© Younger et al. 2015 Licensed under Creative Commons Attribution 4.0 International (CC BY 4) http://creativecommons.org/licenses/by/4.0/

DOI: doi:10.1186/s12862-015-0502-2

Abstract

Background

Major, long-term environmental changes are projected in the Southern Ocean and these are likely to have impacts for marine predators such as the Adélie penguin (Pygoscelis adeliae). Decadal monitoring studies have provided insight into the short-term environmental sensitivities of Adélie penguin populations, particularly to sea ice changes. However, given the long-term nature of projected climate change, it is also prudent to consider the responses of populations to environmental change over longer time scales. We investigated the population trajectory of Adélie penguins during the last glacial-interglacial transition to determine how the species was affected by climate warming over millennia. We focussed our study on East Antarctica, which is home to 30 % of the global population of Adélie penguins.

Methods

Using mitochondrial DNA from extant colonies, we reconstructed the population trend of Adélie penguins in East Antarctica over the past 22,000 years using an extended Bayesian skyline plot method. To determine the relationship of East Antarctic Adélie penguins with populations elsewhere in Antarctica we constructed a phylogeny using mitochondrial DNA sequences.

Results

We found that the Adélie penguin population expanded 135-fold from approximately 14,000 years ago. The population growth was coincident with deglaciation in East Antarctica and, therefore, an increase in ice-free ground suitable for Adélie penguin nesting. Our phylogenetic analysis indicated that East Antarctic Adélie penguins share a common ancestor with Adélie penguins from the Antarctic Peninsula and Scotia Arc, with an estimated age of 29,000 years ago, in the midst of the last glacial period. This finding suggests that extant colonies in East Antarctica, the Scotia Arc and the Antarctic Peninsula were founded from a single glacial refuge.

Conclusions

While changes in sea ice conditions are a critical driver of Adélie penguin population success over decadal and yearly timescales, deglaciation appears to have been the key driver of population change over millennia. This suggests that environmental drivers of population trends over thousands of years may differ to drivers over years or decades, highlighting the need to consider millennial-scale trends alongside contemporary data for the forecasting of species’ abundance and distribution changes under future climate change scenarios.

Item Details

Item Type:Refereed Article
Keywords:climate change ecology, Bayesian skyline plot, palaeoecology, Holocene, molecular ecology, seabirds, Pygoscelis adeliae, last glacial maximum, demography
Research Division:Biological Sciences
Research Group:Evolutionary Biology
Research Field:Biogeography and Phylogeography
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Antarctic and Sub-Antarctic Flora, Fauna and Biodiversity
Author:Younger, J (Ms Jane Younger)
Author:Miller, K (Dr Karen Miller)
ID Code:105761
Year Published:2015
Web of Science® Times Cited:5
Deposited By:IMAS Research and Education Centre
Deposited On:2016-01-14
Last Modified:2016-05-19
Downloads:185 View Download Statistics

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