Abandoned penguin colonies and environmental change in the Palmer Station area, Anvers Island, Antarctic Peninsula

Six abandoned colonies of Adélie penguin (Pygoscelis adeliae) were excavated near Palmer Station, Anvers Island, Antarctic Peninsula, to investigate the occupation history of this species. Sediments from each site yielded abundant fish bones and otoliths and squid beaks that represent prey remains d...

Full description

Bibliographic Details
Published in:Antarctic Science
Main Authors: Emslie, Steven D., Fraser, William, Smith, Raymond C., Walker, William
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1998
Subjects:
Antarctic
Antarctic Peninsula
Anvers
Anvers Island
Palmer Station
Palmer-Station
Antarc*
Antarctic Science
Antarctica
Pygoscelis adeliae
Pygoscelis papua
Online Access:http://dx.doi.org/10.1017/s0954102098000352
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102098000352
Description
Summary:Six abandoned colonies of Adélie penguin (Pygoscelis adeliae) were excavated near Palmer Station, Anvers Island, Antarctic Peninsula, to investigate the occupation history of this species. Sediments from each site yielded abundant fish bones and otoliths and squid beaks that represent prey remains deposited by penguins during the nesting period. Radiocarbon analyses indicate that colony occupation began prior to the Little Ice Age (LIA; 1500–1850 AD ), with the oldest site dating to 644 yrs before present ( BP average reservoir-corrected date with Is range, 603–679 yr BP ). Food remains indicate that the non-euphausiid prey of penguins consisted primarily of a mesopelagic squid (Psychroteuthis glacialis) and two species of fish (Pleuragramma antarcticun and Electrona antarctica) . The relative abundance of the first two prey taxa varied significantly among six sites (X 2 >34.6; df = 10; P <0.001) with colonies dating prior to the LIA having greater representation of squid, and less of silverfish, than those occupied during the LIA. Data from control excavations at three modern colonies indicate a diet similar to that of the pre-LIA sites. These results suggest that Adélie penguins may have changed their diet in response to warming and cooling cycles in the past. In addition, only Adélie penguins are known to have nested in the Palmer Station area prior to the l950s; gentoo (Pygoscelis papua) and chinstrap (P. antarctica) penguins now breeding in this region have expanded their ranges southward in the Peninsula within the past 50 yrs, in correlation with pronounced regional warming.

Similar Items