Diane Gifford-Gonzalez

The shifting baseline of northern fur seal ecology in the northeast Pacific Ocean

Historical data provide a baseline against which to judge the significance of recent ecological shifts and guide conservation strategies, especially for species decimated by pre-20th century harvesting. Northern fur seals (NFS; Callorhinus ursinus) are a common pinniped species in archaeological sites from southern California to the Aleutian Islands, yet today they breed almost exclusively on offshore islands at high latitudes. Harvest profiles from archaeological sites contain many unweaned pups, confirming the presence of temperate-latitude breeding colonies in California, the Pacific Northwest, and the eastern Aleutian Islands. Isotopic results suggest that prehistoric NFS fed offshore across their entire range, that California populations were distinct from populations to the north, and that populations breeding at temperate latitudes in the past used a different reproductive strategy than modern populations. The extinction of temperate-latitude breeding populations was asynchronous geographically. In southern California, the Pacific Northwest, and the eastern Aleutians, NFS remained abundant in the archaeological record up to the historical period ≈200 years B.P.; thus their regional collapse is plausibly attributed to historical hunting or some other anthropogenic ecosystem disturbance. In contrast, NFS populations in central and northern California collapsed at ≈800 years B.P., long before European contact. The relative roles of human hunting versus climatic factors in explaining this ecological shift are unclear, as more paleoclimate information is needed from the coastal zone.

Pastoral Neolithic sites on the southern Mbulu Plateau, Tanzania

As part of a larger project examining the introduction of herding into northern Tanzania, surveys and excavations were conducted at the southern edge of the Mbulu Plateau, documenting the presence of Narosura ceramics dating to the early third millennium BP, as well as a Later Stone Age occupation dated via ostrich eggshell to the tenth millennium BP. This marks the southernmost extent of the Pastoral Neolithic in eastern Africa. The paucity of sites attributable to early herding in this area may be due to a lack of survey in landscapes likely to have been preferred by livestock owners and to extensive contemporary cultivation in those same areas. Links can be drawn between the study area and previously documented sites with Narosura materials near Lake Eyasi, and between the study area and obsidian sources in the Lake Naivasha area of the Rift Valley, making the plateau and its surroundings a potentially promising area for further research.

Anthropogenic Burning on the Central California Coast in Late Holocene and Early Historical Times: Findings, Implications, and Future Directions

Abstract In this final paper, we summarize the results of the eco-archaeological project, address five research questions concerning anthropogenic burning on the central California coast in Late Holocene and early historical times, and outline plans for future research.

The Fauna from Quiroste: Insights into Indigenous Foodways, Culture, and Land Modification

Abstract The CA-SMA-113 archaeofauna suggests that Quiroste Valley people used varied terrestrial and marine foods, generally avoided consuming birds, and maintained more open habitats than typifies the valleys natural climax vegetation. We contextualize habitat-diagnostic rodent taxa from the site with data from a recent live trapping transect only a few kilometers south of Quiroste. California voles, an open country species, were never trapped in closed vegetation but are the second most common identifiable rodent species in the CA-SMA-113 archaeofauna, a divergence that is extremely statistically significant. Based upon the modern live-trapping data, voles should not have been present at all, if Quiroste Valley habitats were unmodified. Their robust presence implies processes favoring grassland maintenance.

Coyote ( Canis latrans ) use of marine resources in coastal California: A new behavior relative to their recent ancestors

Coyotes (Canis latrans) are known to consume marine foods, but the importance and persistence of marine subsidies to coyotes is unknown. Recent access to a marine subsidy, especially if gained following apex predator loss, may facilitate coyote expansion along coastal routes and amplify the effects of mesopredator release. Our goal was to quantify and contextualize past and present marine resource use by coyotes on the central coast of California via stable isotope analysis. We measured δ 13C and δ 15N values in coyotes, their competitors, and their food resources at two modern sites, seven archaeological sites spanning in age from ~3000 to 750 BP, and from historical (AD 1893–1992) coyote and grizzly bear hair and bone sourced from coastal counties. We found evidence for marine resource use by modern coastal California coyotes at one site, Año Nuevo, which hosts a mainland northern elephant seal (Mirounga angustirostris) breeding colony. Seals and sea lions account for ~20% of Año Nuevo coyote diet throughout the year and this marine subsidy likely positively impacts coyote population size. Isotopic data suggest that neither historic nor prehistoric coyotes consumed marine-derived foods, even at sites near ancient mainland seal rookeries. Marine resource use by some contemporary California coyotes is a novel behavior relative to their recent ancestors. We hypothesize that human alteration of the environment through extirpation of the California grizzly bear and the more recent protection of marine mammals likely enabled this behavioral shift.

Reasoning with Zooarchaeological Counting Units and Statistics

When zooarchaeologists work with aggregate data derived from archaeofaunas to study past human behavior, they are advised to assess whether patterns in their datasets could be products of their own decisions about quantification rather than choices of past humans. Chapter 18 revisits common zooarchaeological counting units in the context of probability theory and statistical tests based on it. It outlines the nature of zooarchaeological variables and the appropriate application of parametric and nonparametric statistical tests to them. It describes potential problems with each of the counting units described in Chap. 10 and notes methods for checking for whether these are a problem within one’s datasets, a topic that will be visited in Chap. 22. It discusses the vexing issue of which measure is best for estimating element and taxonomic abundance. An experimental blind test with large datasets suggests that NISP does not perform so well as other counting units such as MNE as a measure of element and taxonomic abundance, however, the latter is liable to aggregation effects. Chapter 18 briefly reviews a recently proposed alternative to these measures, introduced an alternative measure of element abundance: Number of Distinct Elements (NDE), a landmark-based method for skeletal element quantification that is argued to transcend many of the problems of other measures.

Identification: Sorting Decisions and Analytic Consequences

This chapter takes up a matter insufficiently discussed in zooarchaeology: how analysts make decisions about specimen identifiability, both in terms of osteological and of taxonomic identification. This chapter explores the relationship of these two planes of identifiability, citing some key discussions in the literature, and presents an overview with examples of the many factors that can affect specimen identification. Specimens with high osteological but lower taxonomic identifiability are essential to studying human carcass processing, and even nonidentifable specimens are useful in such research. Entire body segments may actually be referred to this category due human processing directed toward them, which means such “minimally identifiable” specimens must be identified, if one wishes to address selective transport systematically. This chapter cites recommendations on communicating novel taxonomic identifications and discusses an inter-analyst agreement experiment that reports good analyst concordance with highly fragmented mammal bones. The chapter offers an example from my own field experience of circumstances that may require an analyst to flexibly alter their identification practices, in effect triaging an archaeofaunal sample to attain the project’s highest priority goals.

Primary Human Effects: Cutting Edge and Percussion Effects on Bone

This chapter summarizes research on modifications inflicted on bone by hominin processors using cutting edges and percussors. It summarizes these implements’ distinctive traces, including slicing, scraping, sawing, chopping marks made by stone and metal tools, and percussion marks produced by hammerstones and stone anvils and by clubbing against anvils, as well as by metal chopping tools. It introduces a vocabulary that distinguishes different stages in tool-aided carcass processing to be used in the balance of the book. Whether and how cut marks on bone surfaces can reliably be used to infer intensity of processing or functional butchery operations is a contentious matter in zooarchaeology and is introduced here. This chapter discusses the overlap of hammerstone impact marks with static loading notches produced by large carnivores. As with the parallel case of trample and cut marks discussed in Chapter 13, many such instances can be clarified by systematic, actualistically informed approaches using multiple lines of contextual and bone surface evidence.

Bone’s Intrinsic Traits: Age Estimation from Mammalian Dentition

This chapter summarizes archaeofaunal methods for estimating age-at-death from teeth. It begins with ageing methods based on dental development features: eruption schedules, cement annuli, and radiological analysis of odontological development, from tooth bud to completely formed tooth. It then describes ageing methods that rely on attrition, or wearing away, of the teeth: occlusal wear-stage analysis and the remnant heights of enamel crowns. It considers taphonomic effects on dentitions of young animals. The chapter comparatively assesses ageing methods in terms of their precision and accuracy, stressing that some imprecision might result from flaws in a method but difficulties with precise age estimation can also arise from the variability inherent to living organisms. The chapter stresses that some research questions can reliably be pursued with age estimates of lower resolution but consistent accuracy.

Human, Animal, Geological Causes of Bone Breakage

This chapter reviews the history of bone breakage research in archaeology, from early studies that assumed spiral fractures were diagnostic traces of deliberate hominin weapon or tool making to those based upon actualistic research, which have shown that such breakage can be produced by multiple actors in a range of situations. The biomedical literature on bone as a material provides useful terms for understanding the circumstances under which bones break. This chapter describes static, dynamic, and torsional loading stresses and describes how intrinsic osteonal organization has a strong influence on overall fracture morphology. It outlines how break surfaces and fracture angles generally reflect the degree to which bone collagen fibers have deteriorated or bone mineral has been replaced in diagenesis. This chapter argues that the presence or absence of surface modifications is an independent line of evidence regarding the effector and actor of bone breakage.