Late Pleistocene/Early Holocene Migratory Behavior of Ungulates Using Isotopic Analysis of Tooth Enamel and Its Effects on Forager Mobility

RESEARCH ARTICLE Late Pleistocene/Early Holocene Migratory Behavior of Ungulates Using Isotopic Analysis of Tooth Enamel and Its Effects on Forager Mobility Suzanne E. Pilaar Birch1*, Preston T. Miracle2, Rhiannon E. Stevens3, Tamsin C. O’Connell2,4 a11111 1 Department of Anthropology and Department of Geography, University of Georgia, Athens, Georgia, United States of America, 2 Department of Archaeology and Anthropology, University of Cambridge, Cambridge, United Kingdom, 3 Institute of Archaeology, University College London, London, United Kingdom, 4 McDonald Institute for Archaeological Research, University of Cambridge, Cambridge, United Kingdom * OPEN ACCESS Citation: Pilaar Birch SE, Miracle PT, Stevens RE, O’Connell TC (2016) Late Pleistocene/Early Holocene Migratory Behavior of Ungulates Using Isotopic Analysis of Tooth Enamel and Its Effects on Forager Mobility. PLoS ONE 11(6): e0155714. doi:10.1371/journal.pone.0155714 Editor: Matthew C. Mihlbachler, New York Institute of Technology, UNITED STATES Received: August 12, 2015 Accepted: May 3, 2016 Published: June 8, 2016 Copyright: © 2016 Pilaar Birch et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: The data is deposited with the Neotoma database, neotomadb.org. The direct URL is http://www.neotomadb.org/uploads/ data_subs/Pillar_Birch_et_al_Croatian_Ungulate_ Isotopes.xlsx. Funding: The Gates Cambridge Trust provided funding for SEPB's PhD, of which this research was a part, as well as substantial support for laboratory preparation and stable isotope analysis of the samples. Radiocarbon dates on samples were provided by a University of Oxford Radiocarbon Accelerator Unit/Natural Environment Research Abstract Zooarchaeological and paleoecological investigations have traditionally been unable to reconstruct the ethology of herd animals, which likely had a significant influence on the mobility and subsistence strategies of prehistoric humans. In this paper, we reconstruct the migratory behavior of red deer (Cervus elaphus) and caprids at the Pleistocene-Holocene transition in the northeastern Adriatic region using stable oxygen isotope analysis of tooth enamel. The data show a significant change in δ18O values from the Pleistocene into the Holocene, as well as isotopic variation between taxa, the case study sites, and through time. We then discuss the implications of seasonal faunal availability as determining factors in human mobility patterns. Introduction The seasonal availability of plant and animal resources was integral to the subsistence and mobility strategies of past human groups [1–6] and the migratory behavior of large herbivore species has long been used as a proxy for the mobility of late Pleistocene hunter-gatherers in Europe, relying on modern ethology as a baseline for interpretation (e.g. Paleolithic Epirus, Greece, [7–10]). Since the end of the last ice age, substantial changes in landscape, climate, and human activity have influenced habitat size, vegetation, and population levels. It is therefore likely that significant changes in herbivore mobility, including preferred pathways as well as range distance, have occurred. Seasonal predictability and reliability of these faunal resources may have been crucial for human survival at times of environmental change or climatic instability. PLOS ONE | DOI:10.1371/journal.pone.0155714 June 8, 2016 1 / 19 Stable Isotope Analysis and Prehistoric Ungulate Mobility Council Grant, #2011/2/12. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. This study investigates the mobility of herbivore prey species at the head of the Adriatic (Istria, Croatia) during the Pleistocene-Holocene transition (12,000–8,000 years ago) and spans the cultural phases of the Late Upper Paleolithic, the Mesolithic, and the early Neolithic. Zooarchaeological evidence attests to the economic importance of ungulate taxa including red deer (Cervus elaphus), ibex (Capra ibex), and chamois (Rupicapra rupicapra) at a number of cave sites in the region throughout time [11–17]. We use intra-tooth stable isotope data from archaeological specimens at three of these cave sites to test assumptions about the prehistoric migratory behavior of these prey species based on modern ethology. The present day migratory behavior of red deer is variable, with movement between habitats due to differences in seasonal forage quality, weather, pests, mating, and current wildlife management practices [18–23]. In addition, adjacent populations of red deer may have very different migration and mobility patterns [18, 24] over variable distances (e.g., from 10–140 km [23]). Migratory behavior is most often described in cold-adapted populations of North American elk (Cervus elaphus canadensis) e.g. [18, 19, 23], which offers a potential analogue for red deer populations extant during the cold climate of the terminal Pleistocene in Europe. If the mobility of this species is predominantly determined by environmental factors in the present, there must be a substantial amount of uncertainty in predicting expected mobility patterns in the past, and red deer may or may not have been migratory depending on specific local conditions. This would have had implications for the lifestyles of hunter-gatherers in the northeastern Adriatic during the late Pleistocene, whose specialized subsistence economy was based on red deer [12–17]. Though most caprids are traditionally regarded as high-altitude taxa, this may be a result of present-day distribution of steep, craggy rock faces at high altitudes rather than an altitudinal preference [25] and archaeological evidence from the study region suggests that they occupied elevations much lower than this (100m above sea level) in the late Pleistocene [26, 27]. Caprids do not migrate laterally across large distances, and most of their movement is related to mating and forage quality (R. rupicapra, [28–29]; R. pyrenaica [30–31]; C. pyrenaica [32]). This suggests that populations of chamois and ibex in the past were likely not seasonally migratory over long distances, making them a more accessible resource throughout the year. Based on the faunal data at the case study sites [15–17] there is a shift away from the late Pleistocene hunting of red deer-whose modern day behavioral ecology suggests are selective migrators-to multiple species, including chamois and ibex, which are assumed to be non-migratory, in the early Holocene. Testing whether the migratory behavior seen in modern populations occurred in the past remains a challenge using traditional zooarchaeological methods. Stable isotope analysis has (...truncated)