4.4 Vertebrate Archaeozoology

The study of vertebrate remains recovered within ancient soils and sediments enables insight into past environmental and climatic conditions (Yalden 2001; Mainland 2008), diet, farming, hunting and herding practices (Charles and Halstead 2001), trade and exchange of animals and animal products (Jones O’Day et al. 2004), and the symbolic and cosmological role of animals in society (Jones O’Day et al. 2004). It is the skeletal and dental remains of vertebrates that are most usually preserved within such deposits. Soft tissue and other non-skeletal material (hides, fur, horn, hooves etc.) will only be found in anaerobic conditions where the absence of oxygen has inhibited bacterial decay (Lyman 1994): examples include waterlogged deposits and very dry or cold environments. In aerated soils, preservation of teeth and bone is dependent on a neutral-alkaline pH soil conditions (pH=7). Acidic soil conditions (pH<7) promote skeletal decomposition, and in soils of lower pHs bone will be absent, poorly preserved (‘spongy’), or recovered only where carbonization had occurred prior to burial, as the burning process removes the inorganic component of bone, effectively mineralising bone and making it more resistant to both biological decay and soil acidity (Lyman 1994).

Vertebrates will have become incorporated in ancient deposits through a variety of mechanisms both anthropogenic and natural (e.g., predators, natural deaths) and have been modified during and after deposition by further such processes (e.g. soil conditions, modification by carnivores, re-deposition). Non-anthropogenic bone accumulations include predator kills and den sites (e.g. hyenas, roosts of owls, eagles and other raptors and lacustrine, littoral and cave contexts which have acted as natural ‘traps’ capturing passing animals (Lowe and Walker 1997). In anthropogenically derived deposits, animal bones are typically found in a disarticulated state, reflecting processing of animal carcasses for food and craft working. Occasionally, articulated bodies are found and may represent natural and accidental deaths, deliberate disposal of fallen animals or activities of predator species (e.g. owl roosts in buildings). The deposition of whole or partial skeletons may also reflect non-economic activities, as part of religious or other symbolic acts (e.g., Morris 2008).

Archaeozoology has two basic applications: palaeoenvironmental reconstruction and analysis of human interactions with animals. Many vertebrate species, particularly the birds and the smaller mammalian fauna (rodents, voles, shrews, mice, etc.) are habitat specific or have specific dietary requirements or environmental tolerances and can be used as indicators of particular ecosystems and/or climatic conditions in the past (Mainland 2008). This type of analysis is more commonly undertaken on naturally accumulated assemblages (see e.g. references in Lowe and Walker 1997; Mainland 2008). Anthropogenically derived archaeofaunas accumulate through human activities – food preparation and consumption, funerary and initiation rites, hunting and herding practices, etc. – and enable insight into diverse human-animal interactions within past societies (see, e.g., references in Reitz and Wing 2008; Charles and Halstead 2004).

Most zooarchaeological research will start with a basic taxonomic and anatomical identification, requiring access to a good modern comparative zoological collection (Reitz and Wing 2008). Subsequent methodological approaches will depend on the assemblage and/or research questions involved, but at a minimum will typically include reconstruction of age-at-death from tooth eruption and wear, modelling of taphonomic modifications, including analyses of bone fragmentation and butchery patterning, biometrics and analyses of palaeopathology. These basic methods are now routinely supplemented by more detailed analyses, including inter alia isotopic studies (e.g., Mulville et al. 2009), aDNA (e.g. Haynes et al. 2005; Chessa et al. 2009) and other biomolecular techniques (e.g., Evershed 2008; Craig et al. 2005), morphometrics (e.g. Cucchi et al. 2009; O’Reagan and Kitchiner 2005), histomorphometrics (e.g. Mainland et al. 2007), skeletochronological analyses (e.g. Chirtz et al. 2009).

The Scottish Resource

Archaeofaunal assemblages

It has only really been since the 1970’s that faunal remains within archaeological contexts in Scotland, as in the rest of the UK, have been routinely and systematically sampled, recovered, analysed and archived. Nevertheless, an interest in archaeofaunal remains as a potential source of evidence for Scottish pre-/history is apparent from the Antiquarian excavations onwards; indeed the observations of some of the 19^th and early 20^th century researchers, such as Turner (1895) on the Oban ‘bone caves’, or Platt’s (e.g. 1934; 1956) work in Orkney and Shetland remain significant sources of evidence today, particularly where the actual assemblages have subsequently been lost.

Conditions conducive to bone survival are not well distributed across Scotland, which is largely dominated by acidic and peaty soils (McCormick and Buckland 1997; Kitchener 1998). Large, well, preserved assemblages are found mainly in the Western and Northern Isles (e.g. Armit 2006; Hunter 2007; Dockrill et al 2009; Parker Pearson et al. 1999), particularly within coastal sands and machair (e.g. Parker Pearson et al. 2004; Moore and Wilson 2011; Bigelow et al. 2005). Good bone preservation is also evident in the limestone caves of the West Highlands (e.g. Creag Nan Uamh, Assynt, Callander et al. 1927; Smoo Cave, Pollard et al. 2005; High Pasture Cave, Drew 2005) and in river gravels, clays and sands (e.g. Bishopbriggs, Jacobi et al. 2009). Anaerobic conditions are very rare but are evident in the larger urban contexts, where proximity to rivers and changing water tables, and large accumulations of waste material have promoted exceptional preservation of vertebrate remains (including soft tissue) in cities such as Edinburgh (e.g. Holyrood Archaeology Project Team 2010; Barclay and Ritchie 2010; Jones 2001), Perth (Bowler 2004; Bogdan et al. in press) and Aberdeen (Cameron and Stones 2001; Hodgson and Jones 1982), as well as some of the smaller Scottish burghs (e.g. Kirkwall, Cox et al. 1998; Elgin, Hall et al. 1998). Crannogs and other structures within littoral and near-shore marine environments are a further source of well preserved bone in a Scottish context (e.g. Hale 2000; Dixon 2004; Crone 2000), though to date comparatively little faunal research has been undertaken on such sites.

Preservation conditions have thus created a resource which is biased geographically and to a lesser extent temporally. This has been exacerbated by a tendency for University research projects to gravitate towards the Highlands and Islands of Scotland, areas which had historically benefitted from extensive Antiquarian and early 20^th century interest (Downes et al. 2005). In the Western Isles, there is thus reasonably good evidence for human-animal interactions from the Mesolithic onwards (McCormick and Buckland 1998; McCormick 2006; Mulville 2005; Mulville 1999; Parks and Barrett 2009) and in the Northern Isles from the Neolithic onwards (McCormick and Buckland 1998; Mainland and Simpson 1995; Bond 2007; Rackham 1989; Mainland 1993; Barrett 2005; Moore and Wilson 2011; Bond et al. 2010). The transition to farming of Neolithic, Bronze Age or Iron Age hunting and herding practices is, however, inadequately known over much of Mainland Scotland (McCormick and Buckland 1998). In contrast, understanding of the historic periods is biased towards the larger urban centres, Perth, Edinburgh and Aberdeen (Bogdan et al. in press; Cameron and Stones 2001; Hodgson and Jones 1982; Holyrood Archaeology Project Team 1998). Non-economic uses of animals have been less well studied, though there is a growing interest in this area (Mulville 1999; Morris 2005). Scottish faunal material has also featured prominently in applications of innovative analytical developments within ‘scientific archaeology’, most notably in the fields of biomolecular and isotopic studies (e.g. Mulville et al. 2009; Haynes et al. 2005; Evershed 2008; Craig et al. 2005) though such research has largely been undertaken outwith Scotland (see below).

There are two good overviews of Scottish faunal change from early post-glacial periods onwards, which provide a synthesis of the faunal evidence for Scotland (Kitchener 1998; McCormick and Buckland 1998), though these do require updating to incorporate more recent research, including some significant assemblages such as Scatness in Shetland, Pool in Orkney and Dun Vullan in the Western Isles, as well as assemblages from the early Medieval period onwards. Some period specific syntheses for the faunal data are also available (e.g., Mesolithic, Kitchiner et al. 2004) but most reviews tend to be both geographically and chronologically focused (e.g. Atlantic Iron Age – Bond 2002; Gilmour and Cook 1998). Mainland and Simpson (2005) provide a multi-period overview of potentials for faunal (and other environmental) research within Orkney. Species specific reviews for Scotland exist for pigs (Smith 2000), horses, cats and dogs (Smith 1998) and for fur-bearing animals (Fairnell and Barrett 2007); Haynes et al. (2005) and Nicholson et al. (2004) include a summary of the Scottish evidence in their papers on the origins of the microfauna of the Northern Isles; Serjeantson (2001; 2009) provides similar overview for various avian species.

Marine resources/fish

The taxonomic identification of fish remains recovered from archaeological sites by sieving, allows reconstruction of the ecology, economy and diet of past human populations; furthermore, data provides information about fishing: development of fishing equipment and fishing techniques. This offers a unique insight into the fishing strategies utilised in the past and on the status of past fish resources in the regions of provenance. The use of biometrical techniques allows the size reconstruction of economically important fish groups. The analysis of otoliths (fish ear stones) provides valuable information on the age of the fish caught, as well as on their season of capture.

The study of archaeological fish remains provides important information of relevance to not only archaeologists but also to those involved in marine/coastal ecology, marine biology and conservation. The long time dimension which archaeology provides allows the exploration of relationships between coastal marine communities and habitats, and indicates where environmental changes may have taken place historically along the coastline.

The first records of fish bone presence in archaeological deposits derive from Antiquarian reports and consist of only notes outlining the ‘presence of fish bone’ (Anderson 1895, Bishop 1914, Calder 1937, Fairhust 1939, Mapleton 1875).

Otoliths of 2nd-3rd year saithe (Pollachius virens) recovered at the Iron Age settlement of Bostadh Beach, Lewis, Western Isles. ©Cerón-Carrasco 2005

The introduction of careful sieving techniques of selected bulk samples during the 1970s and 1980s (Payne 1972, Guerreschi 1973, Williams 1973, Jones 1983, Mantle et al 1984) produced large quantities of tiny microscopic and very small organic elements; these remains derived from a range of very small specimens and a wide range of marine fishes. The result of sieving allowed the first crucial detailed study of fish remains from Mesolithic middens from Oronsay and Colonsay which provided quite considerable evidence on the reliance on saithe (Pollachius virens) by Mesolithic populations as a major source of nourishment (Mellars and Willkinson 1980); furthermore, this study underlined the importance of otolith analysis and its contribution of seasonality reconstruction.

Mellars and Wilkinson’s study gave way to intense analysis of fish remains in Scotland where fishing has been historically a very important industry which provided work and nutrition to a high proportion of the population from the earliest human occupation until its demise as a major industry in the 1960s (Coull 1997).

The first synthesis of fish remains recovered from the Mesolithic to Viking Age sites was done by Barrett et al. in 1999. This publication underlined the importance of such analysis based on material recovered by careful sieving (Barrett 1995, 1997, Ceron-Carrasco 1994, 1998a. 1998b, 1998c , 1999, Colley 1983a, 1983b, 1983c, 1984, 1987, 1989, Jones 1991, Nicholson 1997 , 1998) and gave rise to large scale work on the importance of fishing from prehistory to medieval periods throughout Scotland, but particularly in the Western and Northern Isles (Barrett 2003, 2005, Barrett et al. 2008, Barrett et al. 2001, Ceron-Carrasco 2005, Ingrem 2005). Furthermore, careful sampling and sieving has also provided material to study fishing on the East Coast particularly from medieval deposits (Ceron-Carrasco 1998 , 2000a, 2000b] , 2001, 2007), the material recovered provided archaeological evidence backed up by historical and ethnographic evidenc, of the rise of fishing industry in this area.

An attempt to produce an online database with information on marine fish, mollusca and all other marine organisms that survive in archaeological deposits was undertaken in 2004-06 by Ceron-Carrasco et al. (2007) at the University of Edinburgh. An archaeological database of Marine Resource Exploitation in Scotland (MARES) contains archaeological evidence for marine resource exploitation in Scotland from the earliest known settlement (c. 9000 cal BC) to the end of the Medieval period (c. AD 1500). Currently, MARES provides data for northern and western Scotland relating to fishing, hunting of marine mammals and seabirds, shellfish gathering, seaweed usage, and drift wood procurement. As well as details of archaeological finds, it includes information on site location, discovery and excavation history, context and associations, chronology (including available radiocarbon dates), current location of finds, and bibliographic sources. The data was drawn from a wide range of sources, including published and ‘grey’ literature and collections held by museums, universities, and commercial field units.

Unfortunately MARES has not been updated since 2006 due to lack of financial support and the fact that many of the major projects have not yet been published, understandably raw data will not be released till publication. The database probably only includes the raw data of less than a quarter of the overall fish remains recovered from archaeological sites in Scotland, that have been analysed in the last 15 years or so.

Practitioners and research collections

Until relatively recently, there have been very few archaeozoologists working in Scotland. The commercial units, AOC, Headland, etc. have tended to employ archaeozoologists on an occasional basis, the exceptions being Catherine Smith who has been based in Perth since the 1980s and has worked extensively on Scottish Medieval and Post-Medieval assemblages and Finbar McCormick who was based in Edinburgh with AOC Scotland, until leaving for Ireland at the end for the 1990s, and has published diverse assemblages from across Scotland. Of the Scottish Universities, Edinburgh has had an archaeozoologist, Lazlo Bartosiewicz, in post since the early 2000s, Aberdeen has recently invested in a major archaeozoological research centre led by Keith Dobney, and the University of the Highlands and Islands, Orkney campus has recruited Ingrid Mainland, who is also heading commercial activities in archaeozoology for the commercial unit ORCA. At the National Museums of Scotland, Andrew Kitchiner, Principal Curator of Vertebrate Zoology curates the national faunal collections for archaeology and is engaged in archaeozoological research. Historic Scotland does not, however, directly employ the services of an archaeozoologist (unlike English Heritage which has several archaeozoologists based in its Environmental Studies section at Fort Cumberland and a further two employed as Regional Scientific Advisors).

Over the past three decades perhaps more archaeozoological research on Scottish faunas has been undertaken by researchers working outwith Scotland. This reflects both the paucity of researchers based within Scotland and the strong research activities of English Universities in the Scottish islands: in the Western Isles, Jacqui Mulville (Cardiff and Sheffield); in the Northern Isles,  Julie Bond, Rebecca Nicholson, Ingrid Mainland (Bradford), James Barrett and Jen Harland (York/Cambridge). Scottish faunas have also been widely employed in the development and application of biomolecular, isotopic and other innovative analytical methodologies, again until recently outwith Scotland: e.g., lipids, Bradford, Bristol, York (Craig et al. 2005; Mukerjhee et al. 2008), isotopic analyses, Bradford, Cardiff, York, CNRS (Evans et al. 2009; Mulville et al. 2009; Balasse et al. 2009), aDNA, Durham [Aberdeen] (Haynes et al. 2004 ), dental microwear, Bradford][Orkney] (Mainland 2000), morphometrics, Durham [Aberdeen] (Cucchi et al. 2009) .

A modern reference collection of vertebrate skeletons with a secure taxonomic identification is a fundamental prerequisite for archaeozoological research (Reitz and Wing 2008). In Scotland the foremost modern zoological reference collection for Scottish and European faunas is held at the National Museum, under the curation of Andrew Kitchiner and is open for consultation by researchers. Smaller reference collections for teaching and research are held by the Depts. of Archaeology at Glasgow and Edinburgh Universities, and are actively being developed at the Universities of Aberdeen and the Highlands and Islands. These collections tend to reflect the specific research activities of university staff at the institution and can generally be accessed by contacting the department concerned.

Existing archaeological collections provide a further resource for study, for identifications, comparative study and teaching but perhaps most importantly as an analytical resource. There is an increasing recognition of the value of archive faunal assemblages for application of new methodologies. This is demonstrated well by the changing focus of palaeodietary studies over the last decade, which has seen greater emphasis being placed on the reconstruction of animal diet as a research question rather than as a means through which human diet can be assessed (Thomas and Mainland 2005; e.g. Mulville et al. 2009; Balasse et al. 2009); such projects rely heavily on archived faunal material.

A further important resource for Scottish archaeofaunal research is the living vertebrate population of Scotland. Many Scottish species or breeds are distinctive, either biologically or in terms of their habitat and as such may be used as analogies for past populations, habitat and environmental conditions as well as providing useful genetic data. The Soay sheep on St Kilda (Chessa et al. 2009), the red deer on Rum (Stevens et al. 2006), the Orkney vole (Haynes et al. 2005) and the North Ronaldsay seaweed-eating sheep (Mainland 2000; Balasse et al. 2009) are just some examples of modern Scottish species/breeds which have been used in archaeozoological research.

Marine Resources

Research capacity, in terms of materials for marine resources, is substantial in Scotland as most sites will yield substantial quantities of fish remains for analysis. Unfortunately none of the Scottish universities at present appear to be involved in teaching or stimulating studies of fish remains, the focus of more recent post graduate research in this area derived from the University of York where Dr James Barrett taught in this field until moving to the University of Cambridge where the identification of archaeological cod trade has been undertaken on a method formulated by Barrett et al. (2008). The method is based on isotopic measurements (d13C and d15N) of cod bone collagen and was successfully applied to investigate cod trade from the Viking to Medieval periods in several European archaeological sites. Master degrees in isotope analysis of fish remains have also been undertaken at Durham University (Jimenez-Cano 2010).

At the University of Edinburgh the Department of Archaeology has a zooarchaeological teaching unit which offers postgraduate courses in this subject; however this appears to have concentrated mainly on the study of mammal remains.

Links should be closely established with the University of Aberdeen Marine Biology Laboratory which houses the most complete fish skeletal reference collection for marine fish species of the North Atlantic (which is mainly used for the study of marine mammal diet analysis). They also have facilities for thin-sectioning of otoliths, which is crucial to establish seasonality. This is a great source of scientific analysis as well as the Freshwater Fisheries Laboratory in Pitlochry, for the study of salmon and trout. Other related resources include the archives at the School of Scottish Studies at the University of Edinburgh for ethnographic and historical and analogical studies.

Research priorities

The following research priorities for archaeofaunal studies in Scotland can be suggested; these are by necessity generic and it is anticipated that there will be some overlap with the ScARF period panels.

The faunal history of Scotland

It is apparent from the above that there are significant gaps in the early prehistoric faunal record for much of Mainland Scotland and for the later historic in all regions outwith the major urban centres. A research programme identifying and targeting sites of the relevant date in specific geographic areas which are more likely to preserve faunal remains could help redress this deficit. Of particular potential are lacustrine environments and near-shore marine deposits. The under-utilised urban deposits in the smaller towns and cities of Scotland could also prove useful in extending understanding of later historic periods. It can be anticipated that there will be diverse additional pockets of good bone preservation across Scotland, reflecting underlying geologies and soils; establishing where some of these are on a region-by- region basis and targeting zooarchaeological research in these zones could also prove beneficial.

With regard to period-specific priorities, the following areas can be identified as being critical for better understanding of the history of Scottish archaeofaunas:

The Mesolithic/Neolithic transition. The introduction of domesticated animals to and/or the process of domestication in Scotland represents a significant change in human interactions with animals; yet very little is currently known about the origins of domestication in Scotland, whether any indigenous domestication occurred, or if domesticates were introduced (and in the case of sheep this is a given), the routes by which the these species arrived (see also below).

Bronze Age herding practices. Almost nothing is known about pastoral farming in the second millennium BC in Scotland. There is an urgent need to target sites of this period which are likely to preserve faunal material.

Post-Medieval faunas in Scotland. The period from the 17^th century onwards witnessed one of the most fundamental changes to agriculture in Scotland, with farming practices and breeds introduced across the country. The faunal evidence could provide primary data for this process and its impact on farming and farming society; yet there exist very few faunal collections dating to this period outwith the cities.

Several priorities for thematic research, which cross-cut chronological boundaries can also be identified:

Non-economic uses of animals. There has been a tendency to use Scottish archaeofaunas to address research questions relating to the human diet and subsistence and economic uses of animals with little consideration given to their symbolic or ritual role in past societies. Developing methodologies for identifying and ascribing meaning to variability in depositional practice at different scales (from excavation layer to landscapes) is thus a key area for future research.

The practice of ancient herding systems. Traditionally, archaeozoology has focused on the products of past farming systems, meat, milk, wool, etc. Developments in scientific archaeology, in particular in stable isotopic studies, but also other approaches such as morphometrics and dental microwear analysis are enabling a more holistic understanding of past farming practices; foddering and grazing strategies and their impacts both on the landscape and herd productivity; seasonality of diet; the articulation of such practices within the landscape (intensive vs. extensive grazing, transhumance, sheilings, etc.). While most research on Scottish materials has to date been undertaken outwith Scotland, the facilities and archaeozoologists now in place in Scotland, make this a key area both for future research but also as one in which Scottish institutions will feature prominently internationally.

Biogeography of Scottish faunas. The origins of Scottish fauna, both wild and domesticated – colonisations, introductions, extinctions – is a further key area for research and which again has become more viable through recent methodological developments in scientific archaeology, here aDNA studies and morphometrics. Due to recent investment, Aberdeen has significant strengths in this area, both in terms of staff and facilities and again Scotland and Scottish research questions are well placed to lead the way for future research developments and applications in this area.

Marine Resources. The opportunities are always available; Scotland is surrounded by sea and has immense freshwater resources. Most excavations carried out in Scotland produce fish remains, new techniques in isotopic and related analysis should be encouraged along with the standard analysis. One of the main aims for future research should be to provide data that can be of use in the present and future management of fishery resources and which can be incorporated in the history of marine resource exploitation and uses in Scotland. An online database should be further developed in order to safeguard the raw data which may remain unpublished so that it becomes available to future generations of researchers in Scotland.

Archived faunal resources – collections and publications

Conserving the resource. As outlined above, existing archaeofaunal collections are a valuable resource for future research, especially for novel analytical approaches, as biomolecular and isotopic studies have demonstrated. Many of the newer techniques are destructive, and there is some indication that faunal material is considered more expendable than other archaeological materials. There is thus a need to ensure that museums and other archives do not unintentionally allow an overexploitation of the archaeofaunal resource, particularly for periods or species that may be significant in terms of their quantity or biogeography, while at the same time allowing adequate access to this material. Developing national guidelines for destructive sampling should be one response to this issue.

Disseminating the resource. Accessing the grey literature is a perennial problem for archaeology, and is particularly difficult for specialist areas such as archaeozoology. Facilitating access to published faunal reports and grey literature through development of a publication repository for Scotland, similar to that provided by the ADS, is thus a priority for future development in this area. Large-scale regional comparisons of faunal data (and other environmental) data are a powerful tool for exploration of diverse research questions (e.g. Connelly et al. 2011). Such analyses are, however, beset by problems of data comparability and compatibility. Incorporation of Scottish archaeofaunas in initiatives such as the tDAR/TAG (http://archaeologydataservice.ac.uk/research/tag ) collaboration between the Archaeology Data Service and the University of Arizona which seek to overcome these issues through data management is a further priority.

Practitioners

Archaeozoology in Scotland has had a recent upsurge in staff and facilities, mainly within the University sector which undoubtedly will help promote the various research priorities identified by the ScARF panels and further the profile of the subject, both nationally and internationally. A lack in current provision, however, is within government bodies, most notably Historic Scotland. This makes it difficult to develop national recommendations for, among other issues, sampling, recovery or archiving or for public dissemination and outreach of archaeozoology and other aspects of environmental archaeology (as is undertaken in England by the English Heritage Scientific Advisors and/or the EH zooarchaeological team at Fort Cumberland).