Martu ethnoarchaeology: Foraging ecology and the marginal value of site structure

Abstract

Archaeological investigations of hunter-gatherer site structure have remained largely descriptive, despite significant explanatory advancements by evolutionary approaches to foraging behavior and ecology. To date, calls to incorporate site structure studies within this behavioral ecological framework have largely been ignored. We suggest there is a clear explanation for this. At large spatial extents, human behavior is constrained by patterned ecological variability, as such, a general theory of behavior is likely to characterize key aspects of human decisions. At small spatial extents, human behavior is not constrained by patterned ecological variability, therefore, the human decisions that produce site structure should be driven by mechanical constraints or random variation. However, variation in site structure may be ecologically relevant inasmuch as it informs on landscape level variation in humanenvironment interactions. Drawing on ethnoarchaeological data collected in collaboration with Martu, Aboriginal foragers in Western Australia, here we test empirically-derived, mechanistic predictions on site size and material size sorting to show how these can inform theoretically-derived, adaptive predictions from the Marginal Value Theorem. Results show that site size increases with the number of occupants and hence, the amount of in-patch foraging competition, while size sorting increases with the duration of occupation and hence, in-patch residence time. Combined, these attributes of site structure can be used as proxies of foraging behavior to explain variability in overall foraging yields. With this approach, site structure can provide insights into foraging decisions that can be examined through a general theory of behavior.Ecological and evolutionary approaches 2 in hunter-gatherer archaeology continue to 3 make tremendous strides toward explain-4 ing variation in subsistence (e.g., Broughton 5 et al., 2011; Speth, 2010), settlement (e.g., 6 Byrd et al., 2015; Winterhalder et al., 2010), 7 technology (e.g., Surovell, 2012; Stevens and 8 McElreath, 2015), storage (e.g., Morgan, 9 2012; Whelan et al., 2013), and demogra-10 phy (e.g., Kelly et al., 2013; Williams et al., 11 2015). But despite this progress, studies of 12 site structure remain largely descriptive (e.g., 13 Hill et al., 2011; Speth et al., 2012).14 O'Connell (1995) made this same obser-15 vation twenty years ago, noting the dispar-16 ity between ethnoarchaeological studies of 17 faunal remains and those of site structure. 18 While the former were advancing successful 19 explanatory frameworks, the latter remained 20 stagnant. O'Connell suggested a simple, yet 21 under-appreciated reason for this difference: 22 studies of faunal remains were building on the 23 foundations of a general theory which pro-24 vided predictions a priori about how individ-25 uals are expected to behave in particular cir-26 cumstances, but studies of site structure were 27 based only on observations a posteriori with-28 out any guiding theory. Because the former 29 predic...

Hunter-gatherer residential mobility and the marginal value of rainforest patches

“…Asymptotic functions-the functional form most commonly assumed to characterize ethnographic and archaeological gain curves-performed poorly relative to sigmoidal functions for Batek foraging. One possibility is that gain curves for human foraging data derived from focal follows typically conform to asymptotic curves (20), whereas aggregated camp-level foraging data reflecting landscape-level bioenergetic constraints may evince more variation in gain curve shapes.…”

“…Depleting gain functions have been empirically measured in carcass butchery experiments and applied to the ethnoarchaeological record (16)(17)(18)(19)(20), but gain functions have proven difficult to quantify in ethnographic settings. It is unknown whether Significance Hunter-gatherers are notable for their high levels of mobility, but the ecological and social cues that determine the timing of camp movements (residential mobility) are poorly understood.…”

Spatial patterning and occupation dynamics during the Early Holocene in an archaeological site from the south coast of Tierra del Fuego: Binushmuka I

“…colluvial processes, bioturbation or use of land surface by animals), it is normally assumed that the degree of size sorting is contingent on the duration of the occupation. The longer the stay of the group at a site, the greater and denser is the dispersion of obtrusive waste (O'Connell, 1987;Bartram, Kroll & Bunn, 1991;Clark, 2016;Codding, Zeanah, Bliege Bird, Parker & Bird, 2016). On the other hand, the amount of small material remaining in situ can vary depending on the efficiency of the cleaning technology (Hitchcock, 1987;O'Connell, 1987;Stevenson, 1991).…”

“…On the other hand, the amount of small material remaining in situ can vary depending on the efficiency of the cleaning technology (Hitchcock, 1987;O'Connell, 1987;Stevenson, 1991). In this sense, it is inferred that the increase in duration or number of occupations is correlated to the development level of size sorting processes and the size of the archaeological assemblage (Clark, 2016;Codding, Zeanah, Bliege Bird, Parker & Bird, 2016).…”

Using satellite imagery to evaluate precontact Aboriginal foraging habitats in the Australian Western Desert

“…The founding ' Australian Desert Culture' model 1 , created to explain human occupation of the Western Desert, was grounded in its use of the ethnographic record to characterise traditional land use practices, and continues to influence research today. But modern research explores desert archaeology in diverse ways, using principles of biogeography, evolutionary biology and human behavioral ecology [8][9][10][11][12][13][14] . Those models have enhanced our understanding of traditional forager subsistence and settlement practices, highlighting the complex nature of the Aboriginal land use.…”