The use of forests for pasturing and fodder resources remains globally an important, preventing over-grazing and providing complementary fodder in times of poor pasture. Traditionally, forests in Europe were a rich source of collected forage (leafy hay) in the form of branches and leaves. At the same time, herd animals can have a negative impact on forests, where grazing is unchecked. The first herders of Central and Northern Europe experienced a landscape ‘Bristling with forests and foul swamps’ as described by Tacitus in 98AD . The impact of animals on forests has been a focus of archaeologists for over 40 years. For example, Iversen  highlighted the importance of cattle in the expansion of the initial Neolithic settlements in his landam theory. The elm decline was initial contributed to increased use of leafy hay as animal forage.
How can we study forest pasture and foddering via stable carbon isotopes?
The canopy effect is where plants growing under dense forest canopies will exhibit depleted δ13C values. This is due to a combination of carbon -13 depletion of atmospheric CO2 under the canopy caused by CO2 respired by decaying organic matter and low light intensity at the forest floor decreasing photosynthesis efficiency. Consequently, animals browsing and grazing under heavy forest canopies or being fed leafy hay from these environments will exhibit low carbon isotope values in their tissues. Using this principal, researchers such as Dorothee Drucker and Rhiannon Stevens have explored the use of forests by wild ruminants past and present.
A cautionary note
The issue of equifinality can arise with the interpretation of stable isotopic values because different growing environments can produce similar effects on the stable isotopic ratios of plants. These continue up the food chain. For example, waterlogged environments can have a similar impact on δ13C values of plant communities as a dense forest canopy. Lynch and colleagues interpreted depleted δ13C values observed in British aurochs as a reflection of animals feeding on plants from waterlogged environments. Whereas, a similar study by Noe-Nygaard and colleagues of Scandinavian aurochs suggested these animals were forest dwellers. This is why it is key prior to the interpretation of stable isotopic results that robust interpretative frameworks using paleoenvironmental are created for testing hypotheses.
Independent methods for determining forest foddering
Compound-specific stable nitrogen isotope analysis of collagen amino acids provides an independent means for identifying consumption of woody plants, such as leafy hay. Developed by researchers at University of Bristol, direct evidence of the plant composition of animal fodder (woody/herbaceous) can be uncovered using the dietary β values based on δ15N CSIA of amino acids from incremental samples of dentine from cattle molars. These values represent the Δ15NGlx-Phe values of the plants at the base of the food web, using a known trophic offset of −4.0‰ between cattle and their diet. The dietary β values are then be compared with established ranges of Δ15NGlx-Phe values expected for herbaceous (−5.4±2.1‰) and woody plants (−9.3±1.6‰), based on modern references. Combining incremental analysis of enamel bioapatite and CSIA-AA of dentine of the same tooth provides a powerful method to identify forest pasturing and seasonal use of leafy-hay.
Look out for upcoming papers by myself and colleagues from University of Bristol, and European institutions from Hungary, Poland, France and Germany, discussing the role of forests in LBK cattle husbandry uncovered during the NeoMilk project (ERC-advance awarded to Prof. Richard Evershed).
1. Bogucki, P., 1988. Forest farmers and stockholders. Early agriculture and its consequences in North-Central Europe. Cambridge: Cambridge press.
2. Iversen, J., 1969. The influence of prehistoric man on vegetation, in The Neolithisation of Denmark: 150 years of debate., A. Fischer and K. Kristiansen, Editors. Sheffield Archaeological Monographs: Sheffield. p. 105-16.
Emily Lena Jones is an assistant professor of Anthropology at the University of New Mexico, Cyler Conrad is a Ph.D. graduate student in the Department of Anthropology at the University of New Mexico, and Seth Newsome is an assistant professor of Biology at the University of New Mexico. This post describes their collaborative research at the UNM Center for Stable Isotopes on prehistoric turkey husbandry in the American Southwest.
Maize Fed or Wild Diet?
Turkeys (Meleagris gallopavo) were used for a variety of economic purposes in the prehistoric American Southwest (Lang and Harris 1984). Turkeys were eaten; their feathers were used for blanket production; and their eggs were both consumed for food and used as binders in paint tempera formation. Ancient DNA evidence indicates prehistoric Southwesterners made use of both the wild Merrriam’s turkey (Meleagris gallopavomerriami) and a domestic turkey, which was genetically distinct from both Merriam’s and the Mexican domestic turkey (Speller et al. 2010).
Previous stable carbon (δ13C) and nitrogen (δ15N) isotope studies of Southwestern turkeys suggest that prehistorically, turkeys were predominately fed maize (Kellner et al. 2010; McCaffery et al. 2014; Rawlings and Driver 2010). Maize is a C4 plant, and the turkey bones so far sampled display a strong C4 signal (Figure 2).
Stable Isotope Research
Although previous studies have shown a remarkably consistent picture of turkey husbandry, the sample size from these studies is still relatively small.In addition, most of these studies have focused on sites in the Four Corners region or in Northern New Mexico. We are working to expand this sample to include turkeys from sites from the Middle Rio Grande Valley as well as more sites from high elevations or other “marginal” areas. We are analyzing both turkey bone collagen and apatite to understand the spacing and relationship between organic and inorganic isotope systems (Figure 3). Our data, from sites including Tijeras Pueblo (LA 581), Arroyo Hondo Pueblo (LA 12), and Chamisal Pueblo (LA 22765), suggests a more complex pattern of turkey husbandry practices than has been previously documented for the American Southwest. Within at least some contexts there appears to be a mix of maize-fed and wild-diet turkeys. We look forward to processing more samples and sharing our results in future publications and posts!
Kellner, Corina M., Margaret J. Schoeninger, Katherine Spielmann and Katherine Moore. 2010. Stable Isotope Data Show Temporal Stability in Diet at Pecos Pueblo and Diet Variation among Southwest Pueblos. In Morgan, Michèle E. (ed.) Pecos Pueblo Revisited: The Biological and Social Context. Cambridge, Peabody Museum of Archaeology and Ethnology.
Lang, Richard and Arthur Harris. 1984. The Faunal Remains From Arroyo Hondo Pueblo, New Mexico: A Study in Short- Term Subsistence Change. Santa Fe, School of American Research Press.
McCaffery, Harlan, Robert H. Tykot, Kathy Durand Gore and Beau R. DeBoer. 2014. Stable Isotope Analysis of Turkey (Meleagris Gallopavo) Diet from Pueblo II and Pueblo III Sties, Middle San Juan Region, Northwest New Mexico. American Antiquity 79(2): 337-352.
Rawlings, Tiffany A. and Jonathan C. Driver. 2010. Paleodiet of domestic turkey, Shields Pueblo (5MT3807), Colorado: isotopic analysis and its implications for care of a household domesticate. Journal of Archaeological Science 37: 2433-2441.
Speller, Camilla F., Brian M. Kemp, Scott D. Wyatt, Cara Monroe, William D. Lipe, Ursula M. Arndt and Dongya Y. Yang. 2010. Ancient mitochondrial DNA analysis reveals complexity of indigenous North American turkey domestication. Proceedings of the National Academy of Sciences 107(7): 2807-2812.
Christine Bassett is currently a graduate student working with Fred Andrus in the Department of Geological Sciences at the University of Alabama and holds a B.A. in Anthropology and a B.S. in Geology from the University of Georgia, US. This post is based on research for her M.S. in Geology at Alabama.
Sclerochronology and Paleoenvironmental Reconstruction in the North Pacific Ocean
The archaeological record reflects fluctuating marine conditions from the Aleutian Islands to the Northwest coast of North America during the Late Holocene (Wanner et al., 2008). Though not widely tested, recent research suggests that conditions may have cooled enough during the Late Holocene cold phase to allow sea ice to accumulate as far south as the Northern Pacific Ocean. My research is focused on establishing sclerochronological analysis of Saxidomus gigantea as a means of detecting differences in sea surface temperatures in the Northern Pacific Ocean. Sclerochronological and isotopic analysis of skeletal carbonates can provide a proxy for sea surface temperatures as well as the length of seasons during the recent geological record. My research will contribute to a larger project focusing on human and animal adaptation to climate change led by Fred Andrus (Univerisity of Alabama), Catherine West (Boston University), and Mike Etnier (Portland State University) by providing an additional proxy for reconstructing environmental conditions in the Late Holocene.
Sclerochronology is the study of the growth of invertebrate skeletons. I work exclusively with bivalves, whose distinct growth lines mark regular biologically and environmentally controlled growth intervals (Hallmann et al., 2009). Isotopic analysis of oxygen (δ18O) from growth lines can identify winter growth bands between successive growing seasons. Nadine Hallman and her colleagues (2009) examined the life history of S. giganteus and compared shell precipitation during the organism’s life with oxygen isotopic analysis. They determined that dark bands (Fig. 1) largely co-occurred with peaks in δ18O (Fig. 2). These dark bands mark the beginning and end of a season of growth and the interval between them represent the length of one growing season.
Measuring and comparing the lengths of seasonal shell growth from shells collected at higher latitudes with shells collected from slightly lower latitudes could provide a means of assessing changes in the length of growth seasons, possibly indicating differential sea surfaces temperatures between latitudes. Applying this method to ancient archaeological shells would allow me to test for changes in the length of growing season and by extension, the presence of cold conditions – and possibly sea ice – in the Northern Pacific Ocean during the Late Holocene.
To accomplish this, I plan to collect samples of Saxidomus gigantea from Alaska and Northern British Columbia (Fig. 3). I will analyze δ18O profiles across the organism’s second or third year of growth, the most ontogenetically reliable period of growth, to determine that winter growth bands correspond to peaks in δ18O so that later sclerochronological analysis can be performed. For sclerochronological analysis, I will prepare acetate peels (Fig. 4) so that I can then count lunar-daily growth lines between winter growth bands to quantitatively measure the length of the growing season. Assuming I can detect a difference in the length of the growing season between samples collected at different latitudes, I will apply the same method to ancient samples from the same regions. If the method tested here is successful, sclerochronological analysis of bivalves may be able to contribute to δ18O data interpretation and comparative studies with other organisms to provide a more comprehensive view of changes in SST through recent geological history. Understanding climate in the past contributes greatly to archaeological research that seeks to understand how human behavior, particularly the exploitation of floral and faunal resources, changes as components of the environment change.
Hallmann, N., Burchell, M., Schone, B.R., Irvine, G.V., Maxwell, D., 2009, High-resolution sclerochronological analysis of the bivalve mollusk Saxidomus gigantea from Alaska and British Columbia: techniques for revealing environmental archives and archaeological seasonality. Journal of Archaeological Science, v. 36, pp. 2353-2364.
Wanner, H., Beer, J., Butikofer, J., Crowley, T.J., Cubasch, U., Fluckiger, J., Goosse, H., Grosjean, M., Joos, F., Kaplan, J.O., Kuttel, M., Muller, S.A., Prentice, C., Solomina, O., Stocker, T.F., Tarasov, P., Wagner, M., and Widmann, M., 2008, Mid- to Late Holocene climate change: an overview. Quaternary Science Reviews, v. 27, no. 19-20, pp. 1791-1828.
Planning is currently underway, and further information regarding abstract submission, registration, and travel will be available via the conference website, currently in development.
If you have any questions or would like to be involved in organization, please don’t hesitate to get in touch with the group coordinators, Suzanne Pilaar Birch (sepbirch[at]uga.edu) and Catherine West (cfwest[at]bu.edu).
The 12th International Council for Archaeozoology meeting took place just a little over a month ago in San Rafael, Argentina. I submitted a report on the results of the Stable Isotopes in Zooarchaeology Working Group meeting for the Fall 2014 edition of the ICAZ newsletter, due out shortly and reproduced below.
The meeting was a great success, with lots of interesting papers combining stable isotope methods with a variety of osteological analyses. One of the sessions I gave a paper in was “Stories Written in Teeth”, organized by Florent Rivals, which had papers ranging from serial and bulk sampling of teeth for stable isotope analysis, meso- and microwear studies, cementochronology, and oral pathology, among others. I also attended “Recent Advances in Biomolecular Archaeology”, which also had some good stable isotope papers in addition to DNA-focused ones, and was organized by Jessica Metcalf and Ross Barnett. The opening reception and banquet dinner were highlights. And of course, no conference would be complete without a stop at the local natural history museum.
For those who follow the working group but aren’t ICAZ members (recommended!) I’m reproducing that text here:
Members of the Stable Isotopes in Zooarchaeology (SIZ) Working Group came together for the first time since the group’s formation as a result of the “Integrating Zooarchaeology and Stable Isotope Analyses” conference held at Cambridge University in June 2012. We’ve grown to just about 100 members, and welcomed Catherine West (Department of Archaeology, Boston University) on board as a joint group coordinator. We discussed the development of our existing group website, including the addition of a “Project Page” that will highlight ongoing research projects integrating zooarchaeology and stable isotope analyses and will serve as a resource for students and potential research collaborators. In addition, the website already features a blog, which is always open to new content! [We’re currently looking for submissions, so please do get in touch!]
Another main point of discussion was the date and venue for the upcoming working group meeting, slated for early in 2016. Keep an eye out for an announcement in the Spring newsletter with further details! Finally, the formation of a Faunal Stable Isotope Database, to be integrated with the Neotoma Paleoecology Database (neotomadb.org), was discussed. At this point in time the discussion concerns types of data to be included, data format, and protocols surrounding submission to the database. Interested members of the working group will be involved in these larger issues, while 2-3 data stewards would be directly involved in data management as development progresses.
The Stable Isotopes in Zooarchaeology Working Group will be having a meeting during the upcoming ICAZ conference in San Rafael, Argentina, 22-27 September 2014. We will meet on Wednesday afternoon, from 17:50 – 19:10 (5:50 PM-7:10 PM) in Auditorio B at the Convention Center. Points to be discussed include future working group meetings, group organization, and the creation and management of a stable isotope database that will be linked to the Neotoma Paleoecology Database (Geochemistry and Isotopes Workgroup). See you there!
We’re back with new blog posts after a short summer hiatus. Our first post of the academic year (which has already begun for some of us in the US!) comes from David Orton, who is currently an Early Career Research Fellow on the EUROFARM project at University College London, where he is also a Teaching Fellow in Zooarchaeology. Here he shares research that was conducted during his previous postdoctoral fellowship at the McDonald Institute for Archaeological Research at the University of Cambridge, which was recently published in Antiquity.
A Meta-analysis of Archaeological Cod Remains as a Tool for Understanding the Growth of London’s Northern Trade
The backstory to this research comes in two parts. First, a landmark zooarchaeological study by James Barrett and colleagues (2004) demonstrated an explosion in marine fish consumption in England within a few decades of AD1000. Before this event – dubbed the ‘Fish Event Horizon’ (FEH) in tribute to Douglas Adams – sea fishing seems to have been rare and small-scale.
Second, James and his team applied stable isotope provenancing of cod bones to test whether this FEH represented a local phenomenon or the early onset of long distance trade from northern waters (full disclosure: I joined the project towards the end of this stage, in 2010). δ13C and δ15N signatures were established for six potential fishing regions using 259 samples from more than 10 countries. Applying this ‘target’ specimens from 23 (post)medieval sites around the North Sea (Barrett et al. 2011) and Baltic (Orton et al. 2011), we showed that a significant trade in northern cod existed by the 13th-14th centuries, but that the initial FEH in England primarily entailed local fishing. This raised more questions: when exactly did the trade start, how suddenly, and did the imported fish supplement or replace local catches?
Our new study, just published in Antiquity, combines a new zooarchaeological meta-analysis with the existing isotopic results to tell a clear story regarding cod imports to the city of London. Both elements rely on the same principle: that cod were traditionally decapitated before preservation for long-range trade, and that cranial elements thus normally represent relatively local catches. This allowed us to use head bones to establish regional isotopic signatures in the previous isotope work, but it also means that the cranial:postcranial ratio in consumer sites like London can be a rough index for the relative contribution of imports. We simply compiled all the raw data we could find on well-dated cod bones – almost 3000 specimens from 95 sites, including large datasets from Alison Locker and from MOLA – and plotted it using context-level date ranges.
The data show a very sudden switch to imports in the early/mid 13th C, with frequency of cranial bones dropping off just as the number of vertebrae increases sharply. This fits the isotopic results remarkably well: before about AD1250 almost all sampled specimens seem to be local; afterwards the majority are probable imports. Locally caught cod thus seem to have been substantially and rapidly replaced in Londoners’ diet by traded fish almost 800 years ago. What this meant for the local fishing industry is uncertain, but should become clearer when we look at other towns and species.
Biomolecular provenancing has a unique ability to provide direct evidence for the source of imported bones, but its cost and destructiveness ultimately limit sample sizes and hence the reliability and resolution of the stories it can tell. Integrating it with the much larger samples that can be marshalled from meta-analyses of conventional zooarchaeological data has great potential to overcome this problem.
Orton DC, Morris J, Locker A and Barrett JH (2014) Fish for the City: meta-analysis of archaeological cod remains as a tool for understanding the growth of London’s northern trade. Antiquity 88, 516-530.
Orton DC, Makowiecki D, de Roo T, Johnstone C, Harland J, Jonsson L et al. (2011) Stable Isotope Evidence for Late Medieval (14th–15th C) Origins of the Eastern Baltic Cod (Gadus morhua) Fishery. PLoS ONE6, e27568.
Barrett J, Orton D, Johnstone C, Harland J, Van Neer W, Ervynck A et al. (2011) Interpreting the expansion of sea fishing in medieval Europe using stable isotope analysis of archaeological cod bones. Journal of Archaeological Science38, 1516-24.
Barrett JH, Locker AM, and Roberts CM (2004b) The origins of intensive marine fishing in medieval Europe: the English evidence. Proceedings of the Royal Society of London. Series B: Biological Sciences271, 2417-21. [DOI: 10.1098/rspb.2004.2885]
A number of new and exciting projects are focused on incorporating several techniques in zooarchaeology, including stable isotope analysis, to better understand the complex and intertwined history of humans and certain animals. In this post, Dr. Holly Miller shares some of the goals of one such ongoing research scheme: The Fallow Deer Project.
The Fallow Deer Project
The Fallow Deer Project is an AHRC-funded multi-disciplinary study looking at the cultural history of Dama dama dama, the European fallow deer. As one of two Research Fellows on the project, my role is to investigate the biogeography and management of fallow deer through time. To do this, I am using a combination of isotope analyses (C, N, Sr, S, O) to look in depth at the archaeological remains of ancient and modern fallow deer populations, investigating questions related to the importation of animals, founding herds and changing management practices. Were fallow deer domesticated? Under what circumstances were fallow deer established across Europe? How do human-Dama relationships reveal worldview?
No other species of deer has a closer relationship to people than the European fallow deer, and it is becoming clear that this has been the case for millennia. Since the Neolithic, humans have selectively transported and maintained these elegant animals, moving herds from their native, post-glaciation, range in the eastern Mediterranean, across Europe and eventually the globe. Fallow deer are now one of the world’s most widely-naturalised animals. Wherever they have been introduced they have altered the physical and psychological landscape, and their distribution is a direct record of human migration, trade, behaviour and ideology. In combination with studies of archaeology, history, geography, anthropology, genetics, and osteological research, isotope analysis is being used reveal the cultural significance of the fallow deer as they moved from the Balkans to Barbuda, and everywhere in between.
The project is led by Dr Naomi Sykes (University of Nottingham) Prof. Rus Hoelzel (University of Durham) and Prof. Jane Evans (British Geological Survey). The team are working with researchers from a number of fields and institutions up and down the UK- from archaeologists and art historians, to musicians and deer stalkers.
Our latest contributor is Georgia Roberts. Georgia is currently in the second year of her PhD at La Trobe University, Melbourne, Australia, and holds a Masters in Archaeological Science from Australian National University.
Investigations of Seasonality in the Archaeological Record of Southwestern Tasmania, Australia
Stable isotope analysis can support a range of zooarchaeological research. One such application is investigating seasonality – assessing the season of death of individual animals. When these animals are associated with archaeological sites, we can use this data to infer season of site use.
The rugged limestone karst landscape of southwestern Tasmania, Australia, contains several archaeological cave sites with exceptional preservation. This region has been described as an archaeological ‘province’ sharing many characteristics, including distinctive faunal collections, dominated by Bennett’s wallaby (70% by Minimum Number of Individual [MNI] counts) and the Common Wombat (27% MNI). The current project focusses on two of these sites – Warreen Cave and Bone Cave.
Wombat teeth are continuously growing, capturing the isotopic signature of the surrounding environment in the enamel as it forms. The mandibular incisor is the longest tooth (6-7cm) and records approximately 18 months of isotopic data. By sequentially sampling the enamel, a high-resolution record of local climate (δ18O) and vegetation (δ13C) can be retrieved. By assessing seasonal variation in modern analogues, the data can be used to determine season of death and thus inferred season of site use.
Dr Anne Pike-Tay and colleagues (Pike-Tay et al. 2008) used odontochronological analysis to identify that Bennett’s wallabies, the primary prey species, had been killed in the same season throughout the chronology of each site – autumn/winter for Warreen Cave and summer for Bone cave. My PhD uses stable isotopic analysis of Common wombat (Vombatus ursinus) teeth to test this trend, investigating when and how wombats were being utilised by Tasmanian Aboriginal people at the end of the Pleistocene (35,000 to 11,500 years ago).
This research is supported by the La Trobe University Faculty of Humanities and Social Sciences Internal Funding Scheme, the Australian Archaeological Association Research Grant Scheme and Dr Michael Gagan of the Earth Environment Stable Isotope Laboratories (Australian National University).
Cosgrove, R., Field, J., Garvey, J., Brenner-Coltrain, J., Goede, A., Charles, B., Wroe, S., Pike-Tay, A., Grün, R., Aubert, M., Lees, W., O’Connell, J., 2010. Overdone overkill – the archaeological perspective on Tasmanian megafaunal extinctions. Journal of Archaeological Science 37, 2486–2503.
Pike-Tay, A., Cosgrove, R., Garvey, J., 2008. Systematic seasonal land use by late Pleistocene Tasmanian Aborigines. Journal of Archaeological Science 35, 2532–2544.