The protracted Holocene extinction of California's flightless sea duck ( Chendytes lawi ) and its implications for the Pleistocene overkill hypothesis

Abstract

Bones of the flightless sea duck (Chendytes lawi) from 14 archaeological sites along the California coast indicate that humans hunted the species for at least 8,000 years before it was driven to extinction. Direct 14 C dates on Chendytes bones show that the duck was exploited on the southern California islands as early as Ϸ11,150 -10,280 calendar years B.P., and on the mainland by at least 8,500 calendar years B.P. The youngest direct date of 2,720 -2,350 calendar years B.P., combined with the absence of Chendytes bones from hundreds of late Holocene sites, suggests that the species was extinct by Ϸ2,400 years ago. Although the extinction of Chendytes clearly resulted from human overhunting, its demise raises questions about the Pleistocene overkill model, which suggests that megafauna were driven to extinction in a blitzkrieg fashion by Native Americans Ϸ13,000 years ago. That the extermination of Chendytes was so protracted and archaeologically visible suggests that, if the terminal Pleistocene megafauna extinctions were primarily the result of human exploitation, there should also be a long and readily detectable archaeological record of their demise. The brief window now attributed to the Clovis culture (Ϸ13,300 -12,900 B.P.) seems inconsistent with an overhunting event.flightless birds ͉ overhunting T he late Quaternary extinction of North America's large fauna has been a topic of intense scientific interest for decades, focused primarily on the Pleistocene overkill hypothesis, which suggests that 35 genera of megafauna were driven to extinction in a blitzkrieg fashion by Native Americans Ϸ13,000 years ago (1). This hypothesis has been challenged because of the paucity of supporting archaeological evidence for human hunting of most of the extinct taxa (2), while aspects of the extinctions have also been portrayed as inconsistent with climate change explanations (3). Added to this mix is a recent suggestion that an extraterrestrial impact Ϸ12,900 calendar years B.P. contributed to the megafauna extinctions (4). Here we challenge the overkill hypothesis based on the archaeological record of one of the few North American animals** demonstrably driven to extinction by Native Americans during the Holocene (6, 7)-the often overlooked flightless sea duck (Chendytes lawi).Flightless birds are evolutionary oddities that developed almost exclusively in settings without major populations of terrestrial predators. On many Pacific islands, archaeological findings show that flightless birds were highly vulnerable to human hunting and were quickly decimated soon after humans arrived (8, 9). On the North American mainland many species of birds last disappear from the fossil record near the end of the Pleistocene, but their demise cannot be confidently attributed to human overhunting because their remains are absent from terminal Pleistocene archaeological sites (10). Indeed, a longstanding problem with the overhunting hypothesis is the fact that most genera that went extinct during the late Pleistocene have never been foun...

Relict or colonizer? Extinction and range expansion of penguins in southern New Zealand

“…None of the haplotypes of this species are found in any of the historic or modern samples analysed, indicating that M. waitaha no longer survives. The presence of its bones in archaeological context implies that its extinction was probably caused by overexploitation (Jones et al 2008). This finding is consistent with the fact that large-bodied species were particularly vulnerable to extinction by hunting in prehistoric New Zealand (Holdaway & Jacomb 2000;Duncan & Blackburn 2004).…”

Archaeology, historical ecology and anthropogenic island ecosystems

“…One clear example of prehistoric human-influenced extinction on the islands comes from a flightless duck (Chendytes lawi) that was driven to extinction on the islands and mainland by c. 2400 BP (Jones et al 2008). Impacts to ground-nesting bird species were likely caused by the human introduction of dogs and foxes (Urocyon spp.)…”

Flightless ducks, giant mice and pygmy mammoths: Late Quaternary extinctions on California's Channel Islands

“…BP was obtained from control pit 420 at a depth of *40cm (Erlandson 1991). Four bones in the upper 30-45cm at Daisy Cave in grid E-3 and D-5 (Guthrie 1978(Guthrie : 99, 1980) may also date to the Late Holocene (Erlandson et al 1996;Jones et al 2008). Because both Daisy Cave and CA-SMI-1 contain multiple components that were excavated in arbitrary 6-inch levels, direct 14 C dating is needed to determine whether C. lawi persisted on the Channel Islands as late as it did on the mainland.…”

“…Researchers have long speculated that C. lawi was driven to extinction by ancient human hunting (Grayson 2001;Guthrie 1993;Jones et al 2008;Martin and Klein 1984). These birds undoubtedly were susceptible to human hunting, but burning, butchering or other evidence of processing of C. lawi bones has been documented for only one burned bone from CA-SRI-512, a terminal Pleistocene archaeological site on Santa Rosa Island (Erlandson et al 2011;Rick et al 2008a).…”

“…Chendytes lawi was a flightless duck that had occupied the Channel Islands and mainland coast by at least 40,000 years ago (Guthrie 1993;Howard 1955Howard , 1964Miller 1925). Jones et al (2008) provided an updated synthesis and analysis of the extinction of C. lawi on the mainland and Channel Islands, including a series of direct AMS radiocarbon dates on C. lawi bones from archaeological sites. Although Pleistocene age C. lawi remains have been found as far north as Oregon, the highest concentration of C. lawi bones occurs on the Channel Islands (Jones et al 2008: 4106).…”