@article {2769,
	title = {Recent occupation by Ad{\'e}lie Penguins (Pygoscelis adeliae) at Hope Bay and Seymour Island and the {\textquoteleft}northern enigma{\textquoteright} in the Antarctic Peninsula},
	journal = {Polar Biology},
	volume = {41},
	year = {2018},
	month = {Jan-01-2018},
	pages = {71 - 77},
	abstract = {We excavated active and abandoned Ad{\'e}lie Penguin (Pygoscelis adeliae) colonies at Seymour Island and Hope Bay, Antarctic Peninsula, to determine an occupation history for this species at these sites. Previous research at Hope Bay has indicated an occupation there since the middle Holocene, based on a sediment record from Lake Boeckella. Excavations revealed only shallow and relatively fresh ornithogenic soils in the active colonies at the two localities. At least 53 abandoned pebble mounds were located at Hope Bay of which nine were excavated and four were sampled by probing to recover organic remains to determine their age. Radiocarbon dating of egg membrane, feather, and bone from both sites revealed a young occupation dating to less than ~600 years after correcting for the marine carbon reservoir effect. The mismatch in the geologic record of Ad{\'e}lie Penguin occupation in the northern Antarctic Peninsula, including Lake Boeckella sediments and geologic deposits and lake sediments on King George Island, with more direct evidence of breeding colonies from ornithogenic soils from active and abandoned colonies is hereby referred to as the {\textquoteleft}northern enigma{\textquoteright} as it does not occur in other regions of Antarctica including the southern Antarctic Peninsula, East Antarctica, or the Ross Sea, where the penguin record extends to the early to middle Holocene and matches well with the geologic record of deglaciation and penguin occupation. As yet, there is no convincing explanation for the {\textquoteleft}northern enigma{\textquoteright}.},
	issn = {0722-4060},
	doi = {10.1007/s00300-017-2170-8},
	url = {http://link.springer.com/10.1007/s00300-017-2170-8},
	author = {Emslie, Steven D. and McKenzie, Ashley and Marti, Lucas J. and Santos, Mercedes}
}
@article {2770,
	title = {The rise and fall of an ancient Ad{\'e}lie penguin {\textquoteleft}supercolony{\textquoteright} at Cape Adare, Antarctica},
	journal = {Royal Society Open Science},
	volume = {5},
	year = {2018},
	month = {Jan-04-2018},
	pages = {172032},
	abstract = {We report new discoveries and radiocarbon dates on active and abandoned Ad{\'e}lie penguin (Pygoscelis adeliae) colonies at Cape Adare, Antarctica. This colony, first established at approximately 2000 BP (calendar years before present, i.e. 1950), is currently the largest for this species with approximately 338 000 breeding pairs, most located on low-lying Ridley Beach. We hypothesize that this colony first formed after fast ice began blocking open-water access by breeding penguins to the Scott Coast in the southern Ross Sea during a cooling period also at approximately 2000 BP. Our results suggest that the new colony at Cape Adare continued to grow, expanding to a large upper terrace above Ridley Beach, until it exceeded approximately 500 000 breeding pairs (a {\textquoteleft}supercolony{\textquoteright}) by approximately 1200 BP. The high marine productivity associated with the Ross Sea polynya and continental shelf break supported this growth, but the colony collapsed to its present size for unknown reasons after approximately 1200 BP. Ridley Beach will probably be abandoned in the near future due to rising sea level in this region. We predict that penguins will retreat to higher elevations at Cape Adare and that the Scott Coast will be reoccupied by breeding penguins as fast ice continues to dissipate earlier each summer, restoring open-water access to beaches there.},
	keywords = {population movement, Pygoscelis adeliae, Ross Sea, sea level rise, Stable isotopes},
	issn = {2054-5703},
	doi = {10.1098/rsos.172032},
	url = {https://royalsocietypublishing.org/doi/10.1098/rsos.172032},
	author = {Emslie, Steven D. and McKenzie, Ashley and Patterson, William P.}
}
