Society-funded Research

Investigating human-cetacean relationships in the Outer Hebrides

The Society funded the identification of whale bone from Cladh Hallan, South Uist.

Sperm whale bone from Cladh Hallan

Cetacean bone from Cladh Hallan, identified by the Society of Antiquaries funded work as Sperm whale

Introduction

With over 700 offshore isles, the deep human history of insular Scotland is a dynamic example of biocultural interactions. For the majority of mainland Britain the arrival of farming heralded a major decline in wild resource exploitation, but the islanders followed a different trajectory with hunting, fishing and gathering of terrestrial and marine resources remaining central to food procurement.

This project focuses on the Bronze Age to Norse human relationship with the sea as evidenced in the exceptional cetacean assemblages of the Western Isles (Mulville 2002), from the sites of Cladh Hallan, Cille Phaedair and Bornais, on South Uist. Biomolecular analysis of bone is one of the tools used to examine the material and the project is timed to capitalise on recent advances in identification techniques (Buckley et al. 2014, Evans et al. 2016) and a pilot study undertaken by the applicant.

The pilot proteomics study, conducted on previously unidentifiable cetacean bone from Bornais, supplemented the morphologically identified assemblage. This revealed a wider range of exploited cetacean species than previous demonstrated (Mulville 2002) with an increase in the known number of species present in both the Iron Age and Norse periods and a focus on sperm whale for artefact production in the latter.

The Society of Antiquaries of Scotland has funded the next phase of analysis, which focuses on the identification of cetacean material from the Middle Bronze Age to Early Iron Age occupation of Cladh Hallan, a site which has produced intriguing evidence of the treatment of human and animal remains. Already there are hints that cetacea were used in specific ways on the site: a cetacean facial bone formed part of a stone lined cist, and artefacts of whale bone were found throughout the settlement including examples of the enigmatic ‘blubber mattocks’, found on many of Scotland’s prehistoric coastal sites. The site also produced over one thousand fragments of cetacean bone. These fragments are unidentifiable using morphological methods, however, bioarchaeological analysis can provide insights into the species represented by these remains, giving new insights into Scottish human-cetacean relationships.

Research questions

The overall project combines zooarchaeological, artefact and proteomic analysis to examine the remains of cetacea and to consider:

  1. Cetacean exploitation over time, in the light of wider patterns of marine exploitation, from both the sea and the shore (via strandings);
  2. Patterns of use and deposition of cetacean material;
  3. How interactions with different species of cetacea, and their individual habitats and behaviours, affected the ways in which species were encountered, perceived, used and deposited: to determine if human-cetacean relationships affected the use of cetacean bone.

The key first step, underpinning investigations in these areas, is the identification of cetacean bone to species. This is the first, necessary, step to understanding human-cetacean relationships in Scotland’s past. The Society of Antiquaries of Scotland has funded analysis of cetacean bone samples from Cladh Hallan using peptide mass fingerprinting.

Cetacean bone samples from Cladh Hallan

Cetacean bone samples from Cladh Hallan

Cetacean identification by peptide mass fingerprinting (ZooMS)

The funded work focuses on the use of peptide mass fingerprinting to obtain species identifications of archaeological cetacean bone. This process, known as Zooarchaeology by Mass Spectrometry (ZooMS), derives identifications based on the weights of different collagen peptides surviving within the bone, which are measured using MALDI time of flight mass spectrometry. The weights of certain peptides are unique to individual species, thereby allowing species identifications.

Over 100 samples will be taken from the cetacean bone at Cladh Hallan, from both fragments and artefacts. The first batch, comprising 76 samples taken from fragments, have been processed and analysed. The results are summarised below. The second, and final, batch of samples will be taken from artefacts. This work will take place in the coming months.

 

Spectra of a Blue whale and Sperm whale

Spectra of a Blue whale (top) and Sperm whale (bottom) from Cladh Hallan showing differing peptide weights allowing species identifications

Cetacean species at Cladh Hallan and further work

Analysis of cetacean bone fragments using ZooMS has resulted in the identification of a range of species at Cladh Hallan. Following analysis of the batch 2 samples, the results from this analysis will also be combined with the results of morphological analyses to give a wider picture of cetacean exploitation and use in the prehistoric Hebrides. However, preliminary analysis of the findings from analysis of batch 1 indicates some striking patterns.

The funded work has shown that throughout the Middle Bronze Age, Late Bronze Age and Early Iron Age fragmented cetacean bone appears to have been derived primarily from the larger species of cetacea: Sperm whale, Blue whale, Fin whale, Humpback whale and Right whale. Sperm whale fragments dominate the Middle and Late Bronze Age remains, while fragments of Blue whale bones are most frequent during the Early Iron Age.

The data greatly enhances the findings of previous studies. Using morphological analysis Mulville (2002) identified Sperm whale and Bottlenose whale in the Late Bronze Age phase at Cladh Hallan. The preliminary results from the current study add considerably to this, through the identification of Sperm whale, Humpback whale, Fin whale and Blue whale from this period. Likewise, Mulville’s (2002) study identified Sperm whale, Minke whale, Bottlenose whale and Bottlenose dolphin from Iron Age deposits excavated on Hebridean sites, while this study has shown that both Blue whale and Fin whale were also exploited during the Early Iron Age at Cladh Hallan.

These species identified by this study exhibit a range of behaviours and represent a variety of different offshore habitats. Stranding frequencies also vary. These factors will be considered when interpreting what the presence of these species at Cladh Hallan may mean, in terms of exploitation strategies by prehistoric communities.

This apparent focus of larger species represented by fragmentary bone will also be further investigated to consider the possibility that the bones of large whales were being used for oil extraction, butchery or artefact production, leading to their fragmentation.

Sally Evans
Cardiff University

References

Buckley, M., S. Fraser, J. Herman, N. D. Melton, J. Mulville and A.H. Pálsdóttir (2014) Species identification of archaeological marine mammals using collagen fingerprinting. Journal of Archaeological Science 41: 631-641

Evans, S., I. B. Godino, M. Álvarez, K. Rowsell, P. Collier, R. N. Prosser de Goodall, J. Mulville, A. Lacrouts, M. J. Collins and C. Speller, 2016. Using combined biomolecular methods to explore whale exploitation and social aggregation in hunter–gatherer–fisher society in Tierra del Fuego. Journal of Archaeological Science: Reports, 6: 757-767.

Mulville J (2002) The role of cetacea in prehistoric and historic Atlantic Scotland. Inter. J. Osteoarchaeology 12(1):34-48.