Re-creation of subsistence patterns in Mesolithic Western Europe using faunal and human remains from shell-middens

 Tara J. Horn

 11/10/99   Anth 450, Archaeological theory

  

            Perhaps the most commonly studied aspect of past cultures is garbage.  People throw out trash and allow it to accumulate in middens which archaeologists find today.  For the coastal areas of Western Europe, that rubbish usually takes the form of shell-middens.  Shell middens are often conspicuous mounds on the flat coastal landscapes.  They contain mostly the shells of various species that people exploited for food.  The main reason these mounds are so conspicuous is that with shellfish, the remains take up about twice as much space as what is eaten.   In areas where people exploited large amounts of shellfish, the middens left behind are also very large.  The size of shell middens can be misleading about the importance of shellfish to the people who ate them.  It takes 50,000 oysters to equal the calories provided by one red deer, yet the oyster shells take up many times as much space.  Red deer could have been over 60 percent of a people’s diet, but the abundance of shells makes it appear as if shellfish were more important.   Western European shell-middens are the result of people who exploited coastal resources about 5000 years ago.  Although shellfish formed only a small portion of their diet, the remains of the shells have preserved the evidence of everything else the ate.

            Because of the calcium present in shells, a non-acidic environment exists that is conducive to the preservation of bone.  The analysis of bone found in middens can provide detailed information about the subsistence strategies of the [SHS1] people who left the shell-middens.  Faunal analysis can provide knowledge of which animal species the people hunted, when they  hunted them, and how they used them.

            The coastal areas of Denmark and Portugal are two areas where archaeologists have intensively studied shell-middens.  Faunal analysis of middens has led to reconstruction of  subsistence patterns for these two areas.  I will compare evidence from Denmark and Portugal, showing that two distinct subsistence patterns existed in Mesolithic Western Europe.  I will also present evidence from the specific study of mammalian and human remains from the Cnoc Coig midden of Oronsay island, Scotland.  I will use this to demonstrate how archaeologists use faunal analysis to determine the type of subsistence pattern used by the inhabitants.

            In Denmark, it seems most probable that Mesolithic hunter-gatherers occupied permanent year round base camps near the coast, while specialized hunting parties occupied seasonal camps, obtaining different resources.  Base camp sites can be identified by the size of the shell-middens as well as the food remains present. Because they were occupied by more people for longer periods of time, the base camps have the largest middens as well as the most varied faunal remains.  Mesolithic peoples often set up base camps in sheltered bays or estuaries, areas close to both marine and terrestrial resources.   The people staying at the base camps would have continually caught available fish and shellfish while receiving other game from the hunting camps.

            Those hunting parties staying on the coast would catch marine species such as porpoises, cod and mackerel, swans, ducks and seals.  The parties sent inland would have hunted such terrestrial species as deer or wild boar.   The specialized hunting camps have smaller middens as well as an overrepresentation in the midden of the specific animal being hunted.  Archaeologists can also distinguish base camps and hunting camps by establishing the season of their use.  Base camps of course would be occupied all year, with different specialized camps occupied only during certain seasons.  The season of the specialized occupation can be determined using the faunal remains present. 

            The easiest way to determine the season of occupation is to establish the presence of migrating animals in the midden.  Scientists can also do this by determining the age of juveniles of species that have specific and known breeding seasons.  The latter technique is most commonly used with terrestrial species like red deer.  If the jaws of juvenile red deer are present, then the tooth eruption pattern can provide an age for the individual.  Counting their age in months from the month they were born provides the season when they were hunted.

            In the case of Denmark, many of the smaller camps had specialized economic activities centered on the hunting of migrating sea animals.  There were also camps focused on the hunting of porpoises and others focusing on swans and ducks.  All of these animals are known to migrate to the waters off the coasts of Denmark from other areas in the winter.  Some seasonal camps have an abundance of cod and mackerel present in the middens and both of these species migrate to Danish waters in the summer.  In the autumn parties could easily hunt the harp seals that were migrating into nearby shallow waters and hauling out on to rock skerries.   When hunting parties went out to obtain marine species they would camp near open shoreline or on nearby islands.

            Seasonal analysis of red deer remains found in Danish middens shows that parties hunted them year round.  Parties would camp inland and return to the base camp  with meat and raw materials. Wild boars were hunted by these parties going inland during the winter.  Evidence suggests that red deer and wild boar are the only terrestrial species hunted for food, since they are the only ones found with signs of butchering within the middens.  Since most of the deer and boar remains represent only those parts used for tool manufacture, it is likely that these terrestrial species supplied only a minority of the Mesolithic peoples’ diets.  The pattern found in Denmark represents the first type of subsistence pattern, which is found in  northwestern Europe.

              A different subsistence pattern has emerged for Portugal.  Rather than occupying permanent base camps, it seems more likely Mesolithic hunters and gatherers had two base camps, occupied at different times of the year. In autumn and winter people stayed at base camps near the inland ends of large estuaries.  In the spring and summer people camped in more open coastal areas.  Because the people would move the base camp once a year to follow resources, fewer specialized camps had to be established for hunting.  Whereas in Denmark, small groups moved to the shore to hunt and fish seasonally, in Portugal, the whole group would move to the shoreline.  The Mesolithic people of Portugal would set up specialized camps for catching meagre, a type of fish that migrates to the Portuguese waters in the summer.  In the winter people staying at the base camp would hunt red deer and wild boar.  This pattern, where two base camps are occupied for two seasons each, represents the second subsistence pattern, which is found in southwestern Europe.

            The island of Oronsay, off the west coast of Scotland in the inner Hebrides islands, has an unusually high amount of shell middens for its size.  Extensive research of the site makes it a good example of the specific methods used to analyze mammalian remains, to determine when they were hunted and how they were used  (Grigson and Mellars 1983).  I will also use the site as an example of how to determine which subsistence pattern it falls under, that of northwestern Europe or Southwestern Europe.

            The island of Oronsay is currently about 6 square kilometers in area.  During the Mesolithic occupation however, it was probably less than 4 square kilometers.  Currently, the island is unable to support any trees, due to high winds, but probably had some forested areas during the Mesolithic.  The island did not, however, support any large terrestrial species such as deer or pig.  The dates for the occupation of the island are fairly certain and are around 5500-6200 years BP.  There are several middens on the island but the most extensively analyzed is Cnoc Coig midden.  There is no strong evidence showing that any of the middens represents a base camp, and it is believed that people on the island would have had to live at least part of the year on the mainland.

            For the remains studied, the archaeologists attempted to determine the species, the age and sex of the individuals, what season they were hunted in and for what purpose they were used.  Both MNI and NISP figures were calculated.  Archaeologists identified and analyzed four main species from Cnoc Coig.  In order of abundance they are gray seal, otter, red deer and wild pig. 

            Of the total mammalian remains recovered, gray seals represent 60 percent. Using petrous bones from the rear of the skull the MNI was figured to be at least nine individuals.  The archaeologists established three age groups for the individuals represented, young pups up to five weeks old, juveniles that were one to three years old and adults.  There were nearly equal numbers of males and females present.

            The presence of the young pups provides seasonal evidence.  Assuming gray seals of the past have the same breeding season as gray seals near Oronsay today then the pups were born and hunted during September and October.  Gray seal pups are extremely easy to hunt using clubs and provide about twelve to eighteen kilograms of meat and twenty to thirty kilograms of blubber.

Adult female seals are also vulnerable during this season, but males would mostly be vulnerable during molting season from march to may.  The molting season for females is from January to February.  This provides two possible scenarios, either the seals were hunted from September to October and the males were intentionally selected for their size, or they were also hunted from January to May(Grigson and Mellars 1985).  Analyzing the seal remains alone does not provide enough evidence for either situation, but I believe evidence presented in this paper below will support the latter scenario.

            Using the MNI, it was calculated how many of each bone type could be expected if entire carcasses were present. A ratio was figured for the observed and expected numbers with the purpose of illustrating whether any bone type was over or underrepresented.  Taking into account the differential preservation of certain smaller bones, the archaeologists concluded there were no gray seal bones significantly underrepresented.  This means that the hunters took whole seal carcasses to the site for butchering and most probably consumption.  Like modern Inuit people who exploit seal, those on Oronsay most likely used the gray seals' meat and blubber for food and fuel, and its hide for material.  Seals make up a large part of the diet of modern Inuit peoples, and since seals represent the majority of the remains found at Cnoc Coig, this may have also been the case on Oronsay.  If  this is so, then the inhabitants probably hunted seal for more than two months out of the year.

            The second most represented species at Cnoc Coig is otter.  Otters, like seals, were accessible from Oronsay.  One hundred and twenty-three finds of bones and teeth represent otter, with an MNI of six to seven.  Otters do not have a defined breeding season so people could have hunted them throughout the year (Grigson and Mellars 1985).  The ratio of expected to observed frequencies of bones is similar to that of seals, implying the hunters brought the whole carcass to the site for butchering.  There is, however, one underrepresented bone type, the proximal metapodial end.  The expected rate for this bone is twelve to fourteen, but there was only one present.  This indicates that the proximal metapodial ends were intentionally removed.  This is most likely the result of the animals being skinned with the proximal metapodials being removed with the hide.  Preliminary spatial analysis shows there are possibly one to two whole carcasses represented in the midden, implying they were not butchered for their meat.  Given this scenario, the hunters probably took whole otter carcasses to the site and processed them for their hides.  Some may have been processed for food.  Modern day Inuit who rely heavily on seal rarely eat otter, using only the hides.  Evidence suggests a similar pattern existed on Oronsay.

            In the case of red deer and pig, both were hunted somewhere other than Oronsay.  Both have similar ratios of expected to observed frequencies.  As for the deer, the majority of the finds are antler, which provide some possible seasonality.  The presence of one antler base in the process of shedding would have had to been taken from an animal in April.  The rest of the antlers could have been obtained at various parts of the year, taken off the ground or off an animal.  As with the pig remains, there is a significant lacking of meat bearing bones.  Both the pelvis and scapula are underrepresented given the expected frequencies if whole carcasses were present.  Therefore, it seems there would have been no significant butchery of pigs or deer at the site.  It is still impossible to tell from the given evidence whether or not pig and deer were butchered or consumed somewhere else.  The evidence does show that at the very least raw materials were collected and brought back to the island.

            The evidence so far indicates that gray seals and otters were hunted from the island itself, while part of the group left to hunt red deer and boar, returning with raw materials.   One deer was definitely obtained during April, when someone was still hunting male seals on Oronsay.  Therefore, the entire group could not have left the island to hunt deer.  It can safely be concluded from this evidence that gray seals were definitely used for food.  It is hard to come to firm conclusions about the relative proportion of the diet represented by these seal remains.  It is impossible to determine the role of unpreserved plants or other unpreserved animals in the diet of Mesolithic peoples.

            Analysis of human remains can help to fill in this gap.  Human bone collagen stable isotope analysis can determine the amount and type of protein a person consumed the last ten years of his life.  Stable isotope analysis measures the amount of marine protein versus the amount of terrestrial protein consumed.  For a diet of primarily marine protein, a 13C bone collagen ratio would equal -12%.  For an entirely terrestrial protein diet it would be -20%. Scientists did this test on human remains from Oronsay as well as on human remains from the Vaenget Nord site in Denmark.  In the case of Oronsay, stable isotope analysis was undertaken to determine whether Mesolithic peoples could have possibly lived on the island year round. For year round occupation a heavy reliance on marine resources would have been necessary.  Because the isotope ratio of the bones from Oronsay is -13%, indicating a diet of at least 90% marine, people could have occupied the island year round.

            Further analyses of 15C ratios indicate the Oronsay humans were eating shellfish, fish and marine mammals.  A high proportion of their diet was coming from high trophic level marine mammals like seals. This would support the relatively high frequency of gray seal remains at Cnoc Coig.  This evidence supports the possibility that Cnoc Coig represents a permanent base camp, with specialized parties leaving to obtain and return with more terrestrial resources.  Therefore, the subsistence patterns used on Oronsay most likely belong to the type used in Denmark. 

Similar tests done on remains from Vaenget Nord indicate these people had a diet of about 75% marine protein, comparable to modern day Inuit peoples (Price, Petersen 1987).   This indicates that people on Oronsay may have relied more heavily on seal and other marine resources than even modern Inuit people.  Vaenget Nord is a small seasonal campsite and the people there would have been living in conditions similar to those in the rest of Denmark.

            Analysis of faunal and human remains in shell middens allows us to develop an idea of what life was like for Mesolithic people on the coasts of Western Europe.  Establishment of the hunting seasons allows us to see that two distinct subsistence patterns existed at the same time.  In Northwestern Europe, people occupied a year round base camp while several small hunting parties would set up specialized camps according to the season.  In southwestern Europe, two base camps were occupied throughout the year, with fewer seasonal hunting camps.  The example of the Cnoc Coig midden on Oronsay demonstrates how archaeologists use scientific analysis to determine the season of hunting as well as how the people were using the animal.  This provides the data necessary to determine what kind of subsistence strategy was used.  On Oronsay, the data suggests that people most likely lived on the island year round, exploiting seal as many Inuit peoples do today.  Specialized parties would have ventured to nearby islands or the mainland to hunt deer and boar mostly for raw materials.  Isotope analysis of human bone provides further support for evidence obtained from faunal remains.  Studying the shell middens of Western Europe allows us to reconstruct part of the lives of the people who hunted and gathered there during the Mesolithic.

 

 


REFERENCES CITED

 

 

Burenhult, Goran  editor

1993 People of the Stone Age  Harper Collins, New York, NY

 

Mellars, Paul editor

1987 Excavations on Oronsay  Edinburgh University Press, Edinburgh

 

Price, Douglas and Petersen, Erik Brinch

1987 A Mesolithic camp in Denmark Scientific American, 256:112-121

 

Richards, M.P. and P.A. Mellars

1998 Stable isotopes and seasonality of the Oronsay middens Antiquity 72:178-185

 

Stein, Julie K.

1992 Deciphering a shell midden Academic press, San Diego CA

 

 

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