Oceanographic-related variation in the bone sizes of extinct great auks

Abstract

We measured the bones of extinct great auks Pinguinis impennis that were killed during recent centuries on Funk Island off the northeast coast of Newfoundland. Comparisons of these measurements with those taken elsewhere suggest that great auks from Funk Island, which is situated in a Low Arctic oceanographic region, were larger than conspecifics from Boreal oceanographic regions. This finding is supported by extant alcid species that inhabit Boreal, Low Arctic or Boreal through High Arctic ocean regions and tend to increase in body size with increasing latitude (generally decreasing sea surface temperature). We suggest that paleoecological sea surface temperatures and food webs may have favored oceanographic-related variation in body sizes of great auks. The variances of the bone sizes of great auks from Funk Island were not less than those of a sample of great auk bones collected from Scandinavian archaeological sites that cover an extensive geographic range and that span seven millenia. This finding is inconsistent with a previously suggested latitudinal cline in body size among great auks in Scandinavia. Research techniques and studies that could address questions of great auk feeding ecology and population genetics are considered.