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To date, there have been no large-scale investigations of mule deer (Odocoileus hemionus) from a single site using stable isotopes, but CA-ALA-554 provides the perfect opportunity for such research. CA-ALA-554 is an ancestral Ohlone site in modern-day Pleasanton that yielded abundant deer remains across 83 burials. AMS radiocarbon dates indicate that people lived here and deposited the deer bones between 400 and 2,000 calibrated years before present. Our goal is to document shifts in deer ecology, especially diet and migratory behaviors, across this swath of time using isotopic signals. Analysis of carbon and nitrogen isotopes reveal overall similarity in diet across the sampled population, with slight variation between individuals. Notably, an increase in variation for both δ13C and δ15N is observed between 800 and 1,000 cal BP, indicating that deer were either diversifying their diet locally or coming to CA-ALA-554 from a greater variety of places during this time than they were either before or after. We argue that the increased variation reflects the ecological stress faced by both mule deer and people during the Medieval Climatic Anomaly (650-1,220 cal BP), which forced one or both to alter their respective foraging and hunting practices. 

Stable isotope analysis has been widely used to investigate dietary and geographical information of organisms, but few studies have applied it to archaeological avian remains. Through carbon and nitrogen stable isotope analyses of bone collagen, this study examines the diet sources of several wild bird species in an attempt to discover their foraging patterns and associated human hunting behavior. These avian remains are from CA- ALA-554 in the East San Francisco Bay Area and represent a time span of 900 years, partly overlapping with the Medieval Climatic Anomaly (MCA). We compare the isotopic signatures of samples from different windows of time represented at the site to investigate the influence of droughts during the MCA and the responses of birds and humans. Our findings show that during the MCA, geese had a larger variance in δ13C and δ15N and avian fauna included a greater range of species. This suggests that birds might have migrated farther and widened their diets and ancient humans might have expanded their hunting range and diversified their prey, possibly in response to more challenging environmental conditions. 

ABSTRACT: Stable carbon and nitrogen isotope analyses of bones and teeth at the ancestral heritage Muwekma Ohlone site of Yakmuy ́Ooyákma-tka (“Place of the East Ridge Site”; CA-SCL-215) reveal significant differences in the dietary life history of males and females. Overall, isotope data indicate that site inhabitants were primarily dependent on low-trophic-level foods, likely plants, and minor amounts of marine food for their main source of dietary protein. From tooth dentin serial samples, we found that males and females were similar for δ13C in early childhood (age 1–9 years), but boys were elevated in δ15N by 0.6–1.0‰ relative to girls, indicating boys were accessing slightly greater amounts of higher-trophic-level foods, such as meat from game. The sex-biased difference in δ15N diminishes during the second decade of life, as female δ15N values increase and become equal to males. However, a difference in δ13C emerges during the second decade: female δ13C values are elevated relative to males. This could indicate that teenage females consumed higher amounts of low-trophic-level, marine-derived protein, such as shellfish. During later adult years the difference in δ13C disappears, while males again show an increase in δ15N relative to females. Although these differences are small, they reveal important sex-biased life history patterns during childhood and adulthood in this ancient community. 

We examine the role of marine food across a transect of sites in Monterey County, California, from the Pacific Coast to 70 km. inland. This study presents new stable carbon, nitrogen, sulfur, and strontium isotope data from human bone, and serial samples of teeth, as well as baseline data from a range of plant and animal remains. We estimate dietary contributions using two different mixing models. Results indicate that marine foods contributed between 65-75% of protein budgets on the coast, 30-40% in locations 10 km. from the coast, and just 1-6% 70 km. inland. Serial sampling of teeth, which estimates diet at 0.5-2.0 year intervals, shows that access to marine foods 10 km. from the coast was not marked by high-amplitude pulses, but was more continual and consistent, demonstrating the strong and persistent interconnections of coastal and near-coastal groups. By contrast, people living 70 km. inland were dependent almost entirely on terrestrial foods, consistent with consumption of resources such as pine and manzanita. Although they traded with coastal people for objects such as shell beads, the movement of marine foods themselves was minimal. 

We examine how Late Holocene people living at the ancestral Ohlone site of Yakmuy ‘Ooyákma-tka (“Place of the East Ridge Site” [CA-SCL-215]) interacted with their environment based on the foods they consumed. We examine dietary variation among 32 individuals buried at the site, located within the current city of San Jose. Radiocarbon dates indicate that Yakmuy ‘Ooyákma-tka spans the M4 phase of the Middle Period through the first half of the Middle to Late Period Transition (870 and 1170 ACE). This study examines carbon and nitrogen isotopes to provide insight into dietary variation, focusing especially on differences by sex and age. We show that Yakmuy ‘Ooyákma-tka inhabitants consumed mainly low trophic level resources, consistent with an almost entirely vegetarian based diet. Dietary variation among males and females follows a distinct life history pattern wherein dietary proteins increased markedly in females during their reproductive years and declined in their older years. 

This article reports new carbon, nitrogen, and sulfur isotope data for 10 individuals on the San Francisco Peninsula from CA-SMA-78 (Hamilton Mound 20; n = 6), CA-SMA-160 (Hiller Mound; n = 3), and a previously unrecorded site in downtown San Mateo (n = 1). We also report seven new bone collagen accelerator mass spectrometry radiocarbon dates, three from CA-SMA-78 that fall during the Early-Middle Transition and early Middle Period (ca. 2,400 and 1,700 cal BP), three from CA-SMA-160 that fall during the late Middle and Middle-Late Transition periods (ca. 1,080 and 770 cal BP), and one from the unrecorded site that falls during the Late Middle Period (ca. 1,260 cal BP). Dietary isotopes show a bimodal pattern, with most individuals (n = 8) consuming a mixed marine-terrestrial diet and two a terrestrial-dominant diet (n = 2). We propose two hypotheses to explain this variation, the first suggesting independent family-level hunting and gathering territories combined with little intra-group sharing of food, and the second suggesting exogamous marriage patterns with people migrating from regions to the south. Future isotopic research could provide support for one (or both) of these hypotheses. 

This article reports new carbon, nitrogen, and sulfur isotope data for 10 individuals on the San Francisco Peninsula from CA-SMA-78 (Hamilton Mound 20; n = 6), CA-SMA-160 (Hiller Mound; n = 3), and a previously unrecorded site in downtown San Mateo (n = 1). We also report seven new bone collagen accelerator mass spectrometry radiocarbon dates, three from CA-SMA-78 that fall during the Early-Middle Transition and early Middle Period (ca. 2,400 and 1,700 cal BP), three from CA-SMA-160 that fall during the late Middle and Middle-Late Transition periods (ca. 1,080 and 770 cal BP), and one from the unrecorded site that falls during the Late Middle Period (ca. 1,260 cal BP). Dietary isotopes show a bimodal pattern, with most individuals (n = 8) consuming a mixed marine-terrestrial diet and two a terrestrial-dominant diet (n = 2). We propose two hypotheses to explain this variation, the first suggesting independent family-level hunting and gathering territories combined with little intra-group sharing of food, and the second suggesting exogamous marriage patterns with people migrating from regions to the south. Future isotopic research could provide support for one (or both) of these hypotheses.