Wild Things? Developing sustainable food systems in prehistory.

Abstract

Archaeological investigations on the outer Scottish islands have revealed exceptional and early evidence for the human control and manipulation of animals used as food resources.

Detailed records of faunal introduction and interactions suggest that early settlers introduced red deer to a pristine environment across the dividing seas. On the Northern and Western Isles, red deer populations flourished and became integral to insular lives, just as farming systems spread across the UK and wild food usage declined. Deer, alongside sheep and cattle, became embedded in insular social, ritual and subsistence practices. Limited landmasses and challenging weather systems forced islanders to develop and adapt practices that allowed a wild species to thrive alongside domestic stock and crops for millennia.

Through a close examination of the introduction, management, adaptations and, for some islands, the eventual extinction of deer, this project explores these distinctive and sustainable ways of living with wild animals.

Introduction

The deep time scales and dynamic geographies within Scotland’s insular archaeological record present a unique opportunity for understanding human-animal interactions. The North Atlantic isles (Orkney, Shetland and the Western Isles), have evidence for some of the earliest and most distinctive exploitation strategies in the UK. Early settlers introduced a diverse mammalian fauna, that included livestock and wild species, such as deer, vole and fox, to what was a virtually pristine environment. A novel, mixed management system emerged and red deer, alongside domestic species, became central to sustainable food production for millennia.

These distinctive forms of interactions with wild species challenge existing definitions of a British Neolithic, and subsequent periods, as a production system dominated by domestic foods with a ubiquitous and unidirectional switch from hunting to farming.

Insular Deer

Our project focuses on a comparative analysis of red deer within the North Atlantic islands to examine the diverse ways our ancestors used this species to adapt to insular conditions. There are three main areas of enquiry: the introduction of red deer, their management, and their response to island life. The following section provides detail on each of these interlinked themes:

Deer: Introduction

The source of red deer on the relatively remote Orkney, Shetland and Western Isles remains unclear. These islands, denuded of large mammals during the last ice age, were first visited by early gatherer hunters and later by pioneering Neolithic farmers. Evidence for any extant deer population utilised by the former is scarce, but by the third millennia BC, both domestic species and red deer are being exploited in large numbers.

Our previous research into colonisation pathways employed genetic analysis of red deer ancient DNA (mitochondrial DNA)from across the islands, alongside deer from mainland Britain, Ireland, and Scandinavia. We identified that the first red deer arrivals on Orkney and the Western Isles (c. 6 KYA) had genetic diversity that was inconsistent with coming from -these tested British, Irish or Scandinavian sources, suggesting that they may have arrived from further afield (Stanton, Mulville, and Bruford 2016).To attempt to resolve these questions, we further sequenced (mitochondrial DNA) of red deer from across Britain and its northern islands, to better characterise the ancient DNA diversity of our deer. Preliminary results show that most British deer belong to a single genetic grouping, consistent with a single expansion from the Western refugial population.

However, interestingly, two red deer specimens from the Ness of Brodgar, an early (Neolithic) farming site on Orkney, show a DNA signature that is ancestral to all other ancient red deer on mainland Britain. These results point to a potential link between ancient deer on Orkney and continental Europe, to the exclusion of all of mainland Britain.

Enhanced genetic analysis of red deer from Early Neolithic sites may be the key to unlocking the hitherto unexplained appearance of wildlife in the region, with implications for our understanding of both its natural history, and human trade and diaspora in the area during prehistory.

By creating a new whole-genome dataset for Orcadian and Western Isle deer we will identify levels of relatedness in the deer (modes of introduction and management), signals of potential inbreeding (herd size), estimate how long ago the deer arrived on the islands (timing of introduction), and determine the sex of the individuals in our samples to provide supplementary information for demographic and size/shape analyses (see Bodies below). Our results will determine the extent to which the divergent evolutionary lineages that we see in our previous insular samples are characteristic of the early Neolithic (e.g. Ness of Brodgar) as a whole and facilitate comparisons of Orcadian and Western Isle deer in more detail.

In the future, we aim to add ancient red deer genomes from mainland Britain and Europe to our dataset of insular genomes generated, allowing us to specifically identify the origin of these ancient insular deer.

Deer: Management

Once established, insular deer herds thrived alongside domestic stock. Large numbers of deer were exploited, and they continued to be a key species as conditions on the islands changed, due to direct and indirect anthropogenic pressures(increasing population and land usage) and environmental variation, over the next 5000 years. The analysis of herd structure (age and sex) within farming systems has been used to track responses to changing conditions in domestic stock, but for red deer, the virtual absence of this species has precluded employing similar methods to examine their exploitation in later prehistory (and beyond).

Therefore the islands provide a unique opportunity to examine how a mixed farming/catching/hunting management system evolved and was sustained, particularly as the two sets of islanders (Northern and Western) developed novel, and sometimes, divergent strategies.

For example, during the Neolithic/Bronze Age, on Orkney, the hunting of red deer focused on adult specimens, whilst in the Western Isles a system of red deer calf culling was employed. This divergence of management systems may have contributed to the long-term trajectories of deer populations; they became extinct in Orkney by the late Iron Age, but persist in the Western Isles.

This project will bring together the existing demographic datasets across the island groups to highlight the changing trajectories over time and shed light on why some succeeded whilst others eventually.

Deer: Bodies

The introduction and exploitation of deer are both human-mediated activities; however, it is only through an examination of changes to the deer themselves that we can begin to understand the full impact of insular systems. Animals’ bodies change in size in response to climatic, local environmental and anthropogenic changes and our data suggests that insular deer become smaller than the populations on the British mainland. This diminution occurs at different rates on different island groups with Orcadian deer demonstrating less reduction in size than those on the Western Isles. The application of robust, nuanced biometrical and statistical techniques to our combined dataset will allow us to track how island life impacted deer size and shape.

Tracing any changes in deer body form is complicated by the dual impacts of age and sex on individual variation as well as the characteristics of the founding population. Through a combination of logscale index (LSI) techniques (and mixture modelling (Wolfhagen 2020, and Wolfhagen et al. 2021.) we will be able to introduce a priori information to our analyses and account for the dual impacts of age and sex on body size. This will provide clarity regarding the rate and nature of change in management systems.

Team

Our team is made up of experienced zooarchaeologists and ancient DNA specialists. We have already acquired the bulk of the data and samples, and our previous DNA analysis indicates good preservation with a high chance of acquiring enhanced datasets. Our project will for the first time create a regional substantive dataset that will be informative about the origin and significance of red deer. Within archaeology, identifying the origin of wildlife has implications for our understanding of the transport and management of animals in prehistory.
This project contributes to some of the highest-profile issues in European archaeology, notably the character and spread of early farming and management systems as well as later trade networks.

Ingrid Mainland

UHI Archaeology Institute, Orkney College

Zooarchaeologist with research interests and expertise in palaeodiet (dental microwear, isotope applications), ancient farming economies and the archaeology of food and consumption.

David Stanton

Bioscience, Cardiff University

Evolutionary geneticist interested in understanding how natural and anthropogenic processes are involved in biodiversity change.

Jacqui Mulville

Archaeology and Conservation, Cardiff University

Bioarchaeologist and field archaeologist whose research focuses on osteoarchaeology, human and animal identities, and island archaeologies concentrated on Britain.

Julia Cussans

UHI Archaeology Institute, Orkney

Archaeozoologist with over sixteen years of professional experience working in both the commercial and academic sectors. I have worked on a variety of large-scale projects in Northern Britain and Eastern England as well as numerous smaller projects.

Jesse Wolfhagen

Prudoe College, Department of Anthropology, West Lafayette, USA.

Archaeologist focused on understanding the complex interplay of human-environment interactions and the long-term human impacts on the landscape, driven by adaptations to hunting and herding.

Victoria Mullin

Smurfit Institute of Genetics
Trinity College Dublin

Molecular biologist with research interests in population genetics and genomics. Utilises degraded DNA from archaeological and museum collection specimens, in conjunction with modern genomes, to investigate genetic variation and demography over time.

What next?

Our ambition is to use our results as a springboard to launch a larger research project looking at how multiple species spread and intersected with humans across the Atlantic Archipelago. Insights will also extend to ecological research because cryptic differences in ancestry between different regions may influence ecological models that span these regions.


The key hypotheses examined are:

  1. Deer were introduced to the island from more than one location- addressed by a combination of genetic and size/shape
    analysis
  2. Different forms of sustainable deer stock management systems developed on both islands – addressed by variations in
    species abundance and herd demographics.
  3. A combination of natural and anthropogenic changes contributed to local extinctions – addressed by mixture modelling