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Too much of a good thing: sea ice extent may have forced emperor penguins into refugia during the last glacial maximum
Author(s) -
Younger Jane L.,
Clucas Gemma V.,
Kooyman Gerald,
Wienecke Barbara,
Rogers Alex D.,
Trathan Philip N.,
Hart Tom,
Miller Karen J.
Publication year - 2015
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.12882
Subject(s) - last glacial maximum , population , glacial period , ice sheet , ecology , environmental change , sea ice , climate change , oceanography , geography , biology , geology , paleontology , demography , sociology
The relationship between population structure and demographic history is critical to understanding microevolution and for predicting the resilience of species to environmental change. Using mitochondrial DNA from extant colonies and radiocarbon‐dated subfossils, we present the first microevolutionary analysis of emperor penguins ( Aptenodytes forsteri ) and show their population trends throughout the last glacial maximum ( LGM , 19.5–16 kya) and during the subsequent period of warming and sea ice retreat. We found evidence for three mitochondrial clades within emperor penguins, suggesting that they were isolated within three glacial refugia during the LGM . One of these clades has remained largely isolated within the Ross Sea, while the two other clades have intermixed around the coast of Antarctica from Adélie Land to the Weddell Sea. The differentiation of the Ross Sea population has been preserved despite rapid population growth and opportunities for migration. Low effective population sizes during the LGM , followed by a rapid expansion around the beginning of the Holocene, suggest that an optimum set of sea ice conditions exist for emperor penguins, corresponding to available foraging area.