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Caprine husbandry practices at the prehistoric site of Monjukli Depe in southern Turkmenistan: A Multi-Isotope Perspective

On By Roz GillisIn News, Projects, ResearchLeave a comment

Jana Eger (j.eger@fu-berlin.de)

Department of History and Cultural Studies at the Free University of Berlin

Sheep and goat predominate in the Neolithic and Aneolithic/Chalcolithic faunal assemblages in southern Central Asia and adjacent microregions, yet their husbandry is still incompletely understood. Some aspects of caprine herding practices, such as the annual timing/seasons of birth and feeding in the context of local conditions, have received little attention so far. This case study addresses these aspects by using an integrated approach combining a multi-isotope analysis (nitrogen, carbon, oxygen, and strontium) mainly on caprine teeth/bones with zooarchaeological results and archaeobotanical data from Monjukli Depe in order to explore the life histories of animals herded at the site. Monjukli Depe is in southern Turkmenistan and inhabited in the late Neolithic (ca. 6200-5650 BCE) and again in the early Aeneolithic (ca. 4800-4350 BCE). Excavations at this site have yielded a large, well-preserved animal bone assemblage.

Passing herd along the Kopet Dag behind the yurt during excavation. Photo: Monjukli Depe Project.

In the first step of the research, bone collagen was extracted from mandibles of sheep and goat and analysed for carbon and nitrogen isotopes (FIG 1). A total of 23 caprine individuals were sampled in the study. From this we can detect past environmental conditions and the range of vegetation to which the animals had continuous access during their lives, including their reliance on C3 and C4 plants. While both plant groups occur in southern Turkmenistan today, the preliminary archaeobotanical data from Monjukli Depe point to a predominance of C3 plants.

Jana sampling material for stable isotope analysis at the chemical lab of the Curt-Engelhorn–Center for Archaeometry GmbH, Mannheim (Germany). Credit: Martin Riesenberg.

The next step, was to sequentially sample lower 3rd molars from the sampled mandibles and analysed for carbon and oxygen isotopes. The δ18O and δ13C values provide insights into seasonal changes in diet and fodder composition over the annual cycle. Several second molars were sampled in addition, so that ca. 11 to 12 months of the first year of the animals’ lives were included in the analyses.

δ18O (white circles) and δ13C (black circles) values, and 87Sr/86Sr ratios (black dashes) for two sheep individuals of Monjukli Depe with both second and third molar sampled (Credit: Jana Eger)

In a third step, the δ18O sequences obtained from the teeth were used to assess strontium isotope analysis. From each tooth two sample positions of the highest and lowest δ18O values were selected to measure the strontium ratios (87Sr/86Sr) to investigate the possibility of different grazing locations on a seasonal scale. The δ18O sequences were further used to provide information about the birth seasonality in the Monjukli herd population.

The analysis reveals that a large proportion of caprine individuals received a more diverse vegetation than others with possible contribution of C4 plants in diet – both on a seasonal and long-term basis. Furthermore, the results support a scenario in which sheep and goats were kept in small flocks at ecologically different locations close to the settlement. Herding practices in the Monjukli case seemed to focus on landscape micro-variability rather than exploiting advantages of altitude differences. The study further indicates that sheep and goat were born across multiple seasons within the annual cycle, and they were raised to maintain a continuous supply of fresh milk along with tender meat, consistent with previous suggestions that husbandry was both meat- and milk-oriented.

Overall, the information gained from the investigation helps to draw a more detailed picture of sheep and goat husbandry, including a better understanding of breeding practices and controlled herd security by the people who tended the animals. The data provide evidence of a wide zootechnical knowledge in this early village society.

The results of the multi-isotope investigation, recently published and online accessible here: https://www.sidestone.com/books/mensch-tier-verhaeltnisse-in-monjukli-depe, were viewed through the lens of the interdisciplinary field of Human-Animal Studies, which direct their focus to complex and multidimensional interspecies relations . The interpretation included zooarchaeological study of over 50,000 animal remains and the analyses of zoomorphic representations in the form of miniaturized clay objects. Thus, the stable isotopic results are considered within the wider socio-cultural practices and conceptions of relations between humans and (other) animals at the settlement of Monjukli Depe.

This research derives from the Monjukli Depe Project at the Free University of Berlin (FUB) under the direction of Prof. Dr. Susan Pollock and Prof. Dr. Reinhard Bernbeck, and was undertaken as part of my PhD (2014-2020) within the frame of the Berlin Graduate School of Ancient Studies. The financial support for this study was provided by the German Research Foundation, and Frauenfördermittel of the Department of History and Cultural Studies at FUB.

Forest pasturing and foddering: stable isotope prespectives

On By Roz GillisIn News, ResearchLeave a comment

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 [1]. The impact of animals on forests has been a focus of archaeologists for over 40 years. For example, Iversen [2] 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.

Schematic of the Canopy effect on δ13C values of plants growing under different canopy densities and its relationship to different ruminant tissues (cone collagen/enamel bioapatite)

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).

References

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.