Yuesong Gao; Lianjiao Yang; Jianjun Wang; Zhouqing Xie; Yuhong Wang; Liguang Sun, 2018
Penguin colonization following the last glacial-interglacial transition in the Vestfold Hills, East Antarctica
Palaeogeography, Palaeoclimatology, Palaeoecology. 490: 629–639. doi:10.1016/j.palaeo.2017.11.053
• We report the oldest geological record of penguin colonization in East Antarctica.
• We deduce the deglaciation date, which is earlier than previous records, at the Vestfold Hills.
• We reconstruct local penguin population history using geochemical proxies.
• We propose that expansion of ice-free area is a driving force in penguin colony development.
The population history of the Adélie penguin (Pygoscelis adeliae) and its response to climatic and environmental changes have been widely studied in maritime Antarctica and several glacial refugia of Adélie penguins were dated back to the Last Glacial Maximum. However, the process of colony expansion during the subsequent glacial-interglacial transition was less well-documented. In this paper, we investigate an ornithogenic core from Vestfold Hills, East Antarctica, to improve knowledge of postglacial penguin colonization. Local deglaciation occurred around 15.6 kyr BP, based on a coarse-grained detrital layer, a date that is earlier than most of those reported in other studies from the same region. Geochemical analysis of the core suggests penguins started colonizing the northern Vestfold Hills around 14.6 kyr BP, the oldest geological record in East Antarctica on penguin occupation, and their population exhibited a broadly increasing trend thereafter. The population expanded at approximately 6740 yr BP, in the mid-Holocene, which corresponds to a local climatic optimum. Although this inference is based on population changes of local sub-colonies, it corresponds well to reconstructions of regional climate change, and changes in the penguin population based on genetic studies. From a consideration of the results of previous studies of the occupation history of sea birds following deglaciation in the Arctic, as well as other parts of Antarctica, we propose that sea birds colonized the emerging ice-free areas shortly after local glacier retreat. Over geological time-scales, the availability of breeding habitat is a key factor controlling the population size and activity range of Antarctic Adélie penguins.