David Zeanah

Sexual division of labor and central place foraging: a model for the Carson Desert of western Nevada

Abstract Archaeological models of hunter-gatherer subsistence often imply that the influence of men’s or women’s foraging effort on settlement patterns varied over time, but fail to consider how central place foraging may reflect conflicting subsistence interests between men and women. For example, earlier studies of Carson Desert prehistory suggest a semi-sedentary, gathering strategy replaced a mobile, hunting-oriented strategy in response to diminishing densities of large game. This implies that the influence of men’s and women’s work effort on residential location and mobility changed, but assumes both genders foraged for the common good rather than striving for different goals. A new central place foraging model based on a human behavioral ecology perspective of sexual division of labor considers how men and women might reconcile conflicting foraging interests given likely resource abundance, return rates, and transport costs. Men’s hunting returns must be high enough to reliably provision children for a hunting-oriented settlement pattern to occur. Otherwise, men should logistically hunt out of bases positioned to facilitate women’s foraging. Therefore, a hunting-oriented strategy seems unlikely in the Late Holocene Carson Desert.

Central Place Foraging and Prehistoric Pinyon Utilization in the Great Basin

Great Basin archaeologists eagerly incorporated Binford’s (1980) forager-collector model into their settlement pattern analyses because Julian Steward’s (1933, 1938, 1941) work on the cultural ecology of Great Basin hunter-gatherers predisposed them to think of the influence of resource distributions on foraging and mobility strategies (Rhode 1999; Zeanah and Simms 1999). Thomas’ epistemologies for Monitor Valley and the Carson Desert of Nevada (Thomas 1983a, 1985) stood out as exemplary applications of the model (Bettinger 1991a: 70-73) because they demonstrated that ethnographic Great Basin bands that shared the same culture, language, and technology ran the gamut from pure foragers (i.e., Kawich Mountain Shoshone), through seasonally mixed foragers and collectors (i.e., Reese River Valley Shoshone and Carson Desert Paiute) to full-time collectors (i.e.,Owens Valley Paiute). The dilemma posed by Thomas was that although the forager—collector model captures adaptive diversity among Great Basin hunter-gatherers, it fails to explain why such variability occurred in a region that lacked the global-scale differences in effective temperature posed by Binford as driving the forager—collector continuum. Almost 20 years ago, Thomas noted that “we currently lack the theoretical models to explain this variability” (1983a:39), although he was optimistic that archaeological field research dedicated to development and application of “mid-range” models would eventually yield a theoretical understanding of variability among Great Basin settlement systems.

RISKY PURSUITS: MARTU HUNTING AND THE EFFECTS OF PREY MOBILITY: REPLY TO UGAN AND SIMMS

Abstract We recently demonstrated that prey size is not a reliable predictor of post-encounter return rates for resources Martu hunters regularly handle in Australia’s Western Desert (Bird et al. 2009). Ugan and Simms are skeptical of our calculations of these returns, especially in our inclusion of tracking as pursuit time. Here we review how these variables were recorded and calculated, update the analysis with more data, and clarify the importance of prey mobility and pursuit failures for understanding the contexts of hunting decisions and their archaeological implications.

Mosaics of fire and water: the co-emergence of anthropogenic landscapes and intensive seed exploitation in the Australian arid zone

Abstract In arid Australia, the antiquity, role and ecological contexts of ‘firestick’ farming in seed-based foraging economies remain unclear. We use Landsat imagery to analyse effects of contemporary Martu hunting fires on seed-bearing grasses and forbs. Today, Martu rarely harvest wild seeds but inadvertently foster patches of grass when they burn to hunt burrowing monitor lizards. Therefore, anthropogenic seed patches need only be by-products of fires set to achieve other goals rather than the intended crop of firestick farming. Nonetheless, sustained burning over the long-term creates and maintains closely juxtaposed mosaics of seed and small game patches. We use the marginal value theorem (MVT) to model how pre-contact foragers may have used seed patches within such mosaics in response to climate change and population growth. We show that seeds would have been reliably available to foragers in anthropogenic patches whenever small game hunting returns were low and travel distances to new hunting patches long. Such circumstances probably occurred during the middle to late Holocene when population growth filled better-watered habitats of arid Australia, and climatic variability associated with the El Niño/Southern Oscillation (ENSO) reduced the number of water sources that could support foraging. Prolonged occupation around the water sources that remained triggered the emergence of fine-grained, anthropogenic fire mosaics. If so, the late Holocene proliferation of formalised seed milling equipment closely followed the emergence of firestick farming and signalled the consequent development of seed-based foraging economies, further fuelling population growth and social complexity when more mesic climatic conditions returned. Earlier milling technology during the Pleistocene and early Holocene probably accommodated seed distributions created in fire regimes other than the mosaic burning conducted by Martu today.

FORAGING MODELS, NICHE CONSTRUCTION, AND THE EASTERN AGRICULTURAL COMPLEX

Some proponents of niche construction challenge the validity of optimality models for investigating agricultural origins, but offer no alternative strategy for understanding the economic context of human foraging decisions. They refer to the Eastern Agricultural Complex as an example of how seed cultivation can result from resource enhancement rather than population-induced resource depression, contradicting a prediction inferred from the prey choice model. Low-return seed cultigens were harvested in environments offering more highly ranked hickory nuts in abundance, apparently supporting their interpretation. A marginal value model demonstrates that in years of low mast yield, foragers could more profitably fill food stores from nearby seed plots than from distant hickory trees. Cultivating seeds would have been economically worthwhile when population circumscription constrained mobility, consistent with trends indicating regional population growth. Surges in walnut shell relative to small seeds are also consistent with the model, suggesting that foragers intensified their use of local, anthropogenic vegetation communities as populations grew, stimulating development of horticultural economies. This illustrates the value of foraging models used in conjunction with niche construction for investigating agricultural origins, particularly when model predictions initially fail to accord with archaeological evidence. Algunos defensores del modelo de construcción de nicho disputan la validez de los modelos de estado óptimo en la investigación de los orígenes de la agricultura; sin embargo, no ofrecen una estrategia alternativa para comprender el contexto económico de las decisiones de forrajeo humanas. Estos investigadores utilizan el Complejo Agrícola Oriental como ejemplo de la posibilidad de que el cultivo de semillas pudo haber resultado de la mejora de recursos en lugar de la depresión de recursos inducida por el crecimiento poblacional, lo cual contradice una predicción inferida del modelo de elección de presas. Las semillas de bajo retorno fueron cosechadas en ambientes que ofrecían fuentes de nutrición preferenciales tales como las nueces de nogal en abundancia, aparentemente apoyando estas interpretaciones. Un modelo de valor marginal demuestra que en años de bajo rendimiento de nueces, los recolectores pudieron haber llenado sus depósitos de los semilleros cercanos con más facilidad que si hubieran aprovechado los nogales lejanos. En consistencia con tendencias que indican un crecimiento demográfico regional, el cultivo de semillas habría adquirido valor económico cuando la circunscripción limitaba la movilidad. Los aumentos repentinos de cáscaras de nuez en relación a las semillas pequeñas también son consistentes con este modelo, el cual indica que los recolectores intensificaron la utilización de comunidades vegetales antropogénicas mientras crecía la población, estimulando así el desarrollo de economías hortícolas. Esto ilustra el valor de los modelos de forrajeo utilizados en combinación con la construcción de nicho en la investigación de los orígenes agrícolas, sobre todo cuando las predicciones del modelo no concuerdan con la evidencia arqueológica.