Clovis-age Overkill Didn't Take Out California's Flightless Sea Duck

A team of six scientists, including Jon M. Erlandson of the University of Oregon, pronounced their verdict in the Proceedings of the National Academy of Sciences (online, March 13) after holding court on thousands of years of archaeological testimony taken from bones of the extinct sea duck uncovered from 14 sites on islands off the California Coast and 12 mainland sites from southern California northward.

Erlandson and his co-authors from California Polytechnic State University, the University of California, Los Angeles, the California Department of Parks and Recreation (CDPR) and the California Department of Forestry and Fire Protection (CAL FIRE) demonstrated that humans first hunted the flightless sea duck (Chendytes lawi) more than 10,000 years ago, but the bird persisted until about 2,400 years ago. Their findings that Chendytes survived more than 7,500 years of human predation are based on the first radiocarbon dating of Chendytes bones from six coastal archaeological sites.

Erlandson and colleagues, along with UO alum Don Grayson, now a University of Washington archaeologist, suggest that the drawn-out road to the ducks' extinction raises serious questions about the "Pleistocene over-kill theory" that the Paleoindian Clovis culture rapidly hunted numerous large mammals and other animals to extinction on their arrival in the Americas in the late Pleistocene.

The ducks' lifestyle served them well for millennia, the researchers noted. Many of the birds nested on the Channel Islands off the California Coast, where few predators existed before humans arrived. After seafaring Paleoindians colonized the islands about 13,000 years ago, however, Chendytes may have been driven to smaller and more remote islands. Human population growth, the development of increasingly sophisticated watercraft, and the introduction of dogs and foxes to the islands probably put greater pressure on the birds. Eventually, the flightless duck, like great auk in the North Atlantic, had no place to run.

The five co-authors with Erlandson, an archaeologist in the UO department of anthropology, were: Terry L. Jones (corresponding author), head of social sciences at California Polytechnic; archaeologist Judy F. Porcasi and Thomas A. Wake of UCLA's Cotsen Institute of Archaeology; H. Dallas Jr. of CAL FIRE; and Rae Schwaderer of CDPR. The paper, published online in advance of regular publication, is available on the PNAS Web site. (http://www.pnas.org/cgi/reprint/0711140105v1.pdf)