Thomas A. Wake

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

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 14C dates on Chendytes bones show that the duck was exploited on the southern California islands as early as ≈11,150–10,280 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 ≈2,400 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 ≈13,000 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 (≈13,300–12,900 B.P.) seems inconsistent with an overhunting event.

Archaeological Perspectives on Native American Fisheries of California, with Emphasis on Steelhead and Salmon

Abstract The archaeological record of California was surveyed to gain an understanding of Native American fisheries and to locate the prehistoric distributions of freshwater and anadromous fishes. Over 152,000 piscine elements were added to prior totals. On San Francisco Bay, important prehistoric intertidal fisheries were especially well documented for bat rays Myliobatis californica, sturgeons Acipenser spp., Chinook salmon Oncorhynchus tshawytscha, clupeids, and atherinopsids. The same sites also indicate the former presence of various freshwater species, including steelhead O. mykiss and coho salmon O. kisutch, in tributary streams from which they were extirpated prior to modern surveys. Slow-moving waters of the Central Valley were heavily exploited, with most sites dominated by Sacramento perch Archoplites interruptus, thicktail chub Gila crassicauda, Sacramento suckers Catostomus occidentalis, Sacramento blackfish Orthodon microlepidotus, hitch Lavinia exilicauda, and tule perch Hysterocarpus trask...

Chronology, Subsistence, and the Earliest Formative of Central Tlaxcala, Mexico

We propose that pottery-using villages did not appear in the upland Apizaco region of central Tlaxcala, Mexico, until after 1000 B.C., centuries after such developments in choice locations for maize agriculture. We excavated at two of the earliest known Formative sites in the region. That work revealed abundant intact refuse deposits, allowing us to evaluate an exist ing ceramic chronology with new radiocarbon dates as well as characterize Formative subsistence. Our results support a more general model of emerging sedentism in central Mexico involving population dispersions from prime agricultural areas to zones of higher elevation. The earliest pottery-using agriculturalists in Apizaco were probably migrants from adjacent regions.

Feasting in Viking Age Iceland: sustaining a chiefly political economy in a marginal environment

The authors show that the principal correlates of feasting in Viking Age Iceland were beef and barley, while feasting itself is here the primary instrument of social action. Documentary references, ethnographic analogies, archaeological excavation and biological analyses are woven together to present an exemplary procedure for the recognition of feasting more widely.

Evidence of size-selective evolution in the fighting conch from prehistoric subsistence harvesting.

Intensive size-selective harvesting can drive evolution of sexual maturity at smaller body size. Conversely, prehistoric, low-intensity subsistence harvesting is not considered an effective agent of size-selective evolution. Uniting archaeological, palaeontological and contemporary material, we show that size at sexual maturity in the edible conch Strombus pugilis declined significantly from pre-human (approx. 7 ka) to prehistoric times (approx. 1 ka) and again to the present day. Size at maturity also fell from early- to late-prehistoric periods, synchronous with an increase in harvesting intensity as other resources became depleted. A consequence of declining size at maturity is that early prehistoric harvesters would have received two-thirds more meat per conch than contemporary harvesters. After exploring the potential effects of selection biases, demographic shifts, environmental change and habitat alteration, these observations collectively implicate prehistoric subsistence harvesting as an agent of size-selective evolution with long-term detrimental consequences. We observe that contemporary populations that are protected from harvesting are slightly larger at maturity, suggesting that halting or even reversing thousands of years of size-selective evolution may be possible.

Where were the northern elephant seals? Holocene archaeology and biogeography of Mirounga angustirostris

Driven to the brink of extinction during the nineteenth century commercial fur and oil trade, northern elephant seal (NES, Mirounga angustirostris) populations now exceed 100 000 animals in the northeast Pacific from Alaska to Baja California. Because little is known about the biogeography and ecology of NES prior to the mid-nineteenth century, we synthesize and analyze the occurrence of NES remains in North American archaeological sites. Comparing these archaeological data with modern biogeographical, genetic, and behavioral data, we provide a trans-Holocene perspective on NES distribution and abundance. Compared with other pinnipeds, NES bones are relatively rare throughout the Holocene, even in California where they currently breed in large numbers. Low numbers of NES north of California match contemporary NES distribution, but extremely low occurrences in California suggest their abundance in this area was very different during the Holocene than today. We propose four hypotheses to explain this discrepancy, concluding that ancient human settlement and other activities may have displaced NES from many of their preferred modern habitats during much of the Holocene.

Prehistoric Sea Turtle Hunting on the Pacific Coast of Mexico

Archaeological sites on the west coast of Mexico provide long-term records of human predation on sea turtle populations. These large reptiles, valuable for their meat, eggs, shell, oil, and skin, are easily obtained from nesting beaches, but prolonged predation can disrupt rookeries and lead to population fragmentation and local extirpation. Our recent excavations at two sites in coastal Guerrero near Acapulco indicate that people hunted sea turtles, most likely from nesting grounds, by at least 5500 cal yrs BP and significantly reduced their local availability within a 3,000 year period. These data help provide a deeper historical and environmental framework

ARCHAEOLOGICAL SEWELLEL (APLODONTIA RUFA) REMAINS FROM DUNCAN'S POINT CAVE, SONOMA COUNTY, CALIFORNIA

Abstract Nine sewellel (Aplodontia rufa) bone specimens are identified in the Duncans Point Cave vertebrate archaeofauna. At least 3 individuals are represented and 3 specimens exhibit evidence of deposition in the cave as carnivore prey. The extralimital presence of A. rufa near the mouth of the Russian River demonstrates their occurrence over a wider area during the mid-Holocene and raises the possibility of the existence or recent extirpation of a 3rd isolated coastal Californian population of the species. Based on the presence of bones of A. rufa in the Duncans Point Cave archaeofauna and the availability of suitable habitat in the region, a detailed survey of the area surrounding the mouth of the Russian River is warranted.

Adapting the bioblitz to meet conservation needs: Bioblitz for conservation

When conservation strategies require new, field-based information, practitioners must find the best ways to rapidly deliver high-quality survey data. To address this challenge, several rapid-assessment approaches have been developed since the early 1990s. These typically involve large areas, take many months to complete, and are not appropriate when conservation-relevant survey data are urgently needed for a specific locale. In contrast, bioblitzes are designed for quick collection of site-specific survey data. Although bioblitzes are commonly used to achieve educational or public-engagement goals, conservation practitioners are increasingly using a modified bioblitz approach to generate conservation-relevant data while simultaneously enhancing research capacity and building working partnerships focused on conservation concerns. We term these modified events expert bioblitzes. Several expert bioblitzes have taken place on lands of conservation concern in Southern California and have involved collaborative efforts of government agencies, nonprofit organizations, botanic gardens, museums, and universities. The results of expert bioblitzes directly informed on-the-ground conservation and decision-making; increased capacity for rapid deployment of expert bioblitzes in the future; and fostered collaboration and communication among taxonomically and institutionally diverse experts. As research and conservation funding becomes increasingly scarce, expert bioblitzes can play an increasingly important role in biodiversity conservation.