Isotopic Evidence for Long‐Distance Mammal Procurement, Chaco Canyon, New Mexico, USA

Abstract

Previous research on the prehistoric communities of Chaco Canyon, New Mexico (ca. A.D. 800–1250) provides evidence of an extensive procurement system of nonlocal food and economic goods. In this paper, we use oxygen and strontium isotope analyses to establish whether animal protein followed a similar pattern. We contextualized our isotopic analyses of the archaeofaunas from recent excavations at Pueblo Bonito with data on modern faunas across an area of approximately 100,000 km2 around the site. Our results show that most archaeological deer, rabbits, and prairie dogs were obtained from >40 km away from Pueblo Bonito with the latter two likely being garden hunted. The Chuska Mountains west of Chaco Canyon and more distant San Juan Mountains to the north were the main source areas. These results closely align with previous results on architectural wood, corn, and other key resources. The importation of small game animals suggests that the local supplies could not meet the needs of the community. Long‐distance meat procurement may have been embedded within a more complex network of ritual‐goods exchange or tribute that helped to offset the transport costs. Resource depletion may have contributed to the eventual abandonment of the region during the Medieval Warm Period.

Stable Oxygen Isotope Sourcing of Archaeological Fauna From Chaco Canyon, New Mexico

“…There are no significant differences between modern rodents and modern lagomorphs (mean lagomorph δ 18 O = −0.45‰; mean rodent δ 18 O = 0.98‰ [Welch two-sample t -test, t = −1.3528; df = 17.563; p > 0.1]).

Figure 2. Box plots showing the distribution of enamel δ 18 O (VPDB) of (a) modern, local Chaco Canyon fauna and fauna from three archaeological sites within Chaco Canyon: (b) the Pueblo Bonito middens (from Grimstead, Quade, and Stiner 2016), (c) Pueblo Bonito's Room 28, and (d) Bc Site 57. Values from the Pueblo Bonito middens data reflect a correction of +0.36‰ to account for different treatment protocols (see text and Pellegrini and Snoeck 2016).

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“…Using δ 18 O values from our modern small-mammal (lagomorphs and rodents) dataset, we applied the regression models proposed by Grimstead, Quade, and Stiner (2016) to calculate a predicted elevation for each specimen. These regression models consistently overestimated the elevational origins of the modern small mammals; only 17.6% of small-mammal specimens collected in Chaco Canyon were predicted to fall within their known elevational ranges (Table 1).…”

“…Surprisingly, given earlier zooarchaeological interpretations, Grimstead, Quade, and Stiner (2016) conclude that all sampled specimens, both small and large animals, produced results indicating long-distance acquisition, minimally 40 km for all specimens and 70 to 100+ km for some deer. Few specialists would likely disagree with the sourcing of large game outside Chaco Canyon, but Badenhorst, Driver, and Maxwell (2016) have challenged the conclusion that small animals were imported.…”

“…The many factors potentially contributing to δ 18 O variation in Chaco Canyon highlight the necessity of comparing archaeological remains with modern fauna before ascribing causality to observed patterns. The only published oxygen isotope dataset for archaeological Chaco fauna that has been used to identify source areas (Grimstead, Quade, and Stiner 2016; see Akins 1984; Badenhorst, Driver, and Maxwell 2016) does not include modern fauna from the canyon as a baseline. Understanding the expected variation within a local population is critical when examining potential long-distance sources for resources.…”

“…In particular, Grimstead, Quade, and Stiner (2016) argue that oxygen isotopes can distinguish local from long-distance procurement strategies and thus provide a test of the general assumption that small game were local and large game were not (and were thus expensive to obtain). As a substitute for modern comparative fauna from Chaco, Grimstead, Quade, and Stiner (2016) used δ 18 O ratios from modern small mammals around the greater San Juan Basin to develop regression models with significant trends correlating the isotopic ratios to the elevation at which each specimen was collected. This altitude effect is well established (Ambach et al 1968; Bowen and Wilkinson 2002; Gonfiantini et al 2001).…”