The palaeoenvironment of humans and marine birds of the Aleutian Islands:: three millennia of change

A unique window into the biological history of the Aleutian Islands is provided by the zooarchaeology of early human sites. We focus on the palaeoavifauna hunted by early Aleuts who inhabited Amchitka and Buldir islands (central Aleutians), and Shemya Island (western Aleutians) from c. 3500 yr ago to the present. Most of the seabird species recovered from these early sites varied widely in distribution and abundance through time and space. Pelagic procellariids such as short-tailed albatrosses and short-tailed shearwaters were present and abundant at most sites and at most times. During periods of increased temperatures and precipitation (e.g. 650-1100 yr BP), nearshore foragers such as cormorants and parakeet auklets increased in abundance, but during periods of cooling (e.g. 1800-2100 yr BP), piscivorous birds feeding offshore, such as murres and kittiwakes, predominated. Over three millennia, we found that marine bird populations were negatively correlated with temperature and positively correlated with precipitation. We detected hunter-related depletions of populations breeding in accessible colonies at small scales of space and time, but we did not observe widespread or long-term effects. We conclude that local oceanography and regional changes in prey bases caused by environmental and climate change in the past had a significant impact on the distribution and abundance of Aleutian marine birds.