A team led by Lua Valenzuela, researcher at the University of the Balearic Islands, has recently published a
new article on animal mobility in the international scientific journal The Journal of Islands & Coastal Archaeology.
The study of animal mobility in the Balearic Islands during the Bonze and Iron Ages provides us with relevant information to understand how past communities interacted with their environment and exploited their resources. It also allows us to detect how these populations interacted with other communities, both within and outside the archipelago. The results of this research will be presented at the upcoming
3rd European Archaeology Conference to be held at the Museu de Menorca on June 14.
Currently, one of the best ways to address these questions is by
analysing the strontium isotopes present in the tooth enamel of animals recovered from archaeological sites. This method is based on the fact that, when we ingest food or water while our bones are being formed, our organism incorporates the isotopes of these elements, which have previously absorbed the isotopes from the geological environment where they were found.
In other words, by analysing the isotopes in the enamel of the animals, in this case sheep and goats, we record a kind of geological ‘signal’ that indicates whether these individuals ate during their first two years of life in the surroundings of the site where they have been recovered or whether, on the contrary, they moved around other places.
In chronological terms, the archaeological sites selected correspond mainly to the Middle and Late Bronze Age, that is, to the period of the navetas, although some later sites, corresponding to the Talayotic period, have also been included. Another important criterion followed has been to represent as many areas as possible (for example, coast, inland and mountain) in order to have a more global view of the livestock farming practices of these societies, avoiding possible local behaviour. At the same time, a functional criterion has also been followed in which sites with different functionalities have been analysed (e.g. funerary, habitat, coastal cape) to see if there is a relationship between herd management that responds to this criterion and to have a more global vision.
Sites analysed
The sites analysed in Mallorca are the Cueva del Campo del Obispo (Sencelles), Es Turassot (Costitx), Closos de Can Gaià (Felanitx), and s'Illot des Porros (Santa Margalida). As for Menorca, samples from Clariana (Ciutadella), Cala Blanca (Ciutadella), Es Coll de Cala Morell (Ciutadella), and Cornia Nou (Maó) were studied, and as for Formentera, the analyses focused on the site of Cabo de Barbaria II. All of these samples were compared with the results obtained a few years ago at Sa Ferradura (Porto Cristo) and S'Hospitalet Vell (Manacor).
Finally, a total of 92 samples corresponding to 74 individuals from 11 archaeological sites were analysed. These data have been discussed with the data published in a previous work, so that this study comprises a total of
149 enamel samples corresponding to 125 individuals,
making it the most extensive study carried out to date in the Balearic Islands.
Another novelty is that in this study, consecutive micro-samples were taken from some of the teeth, which made it possible to observe whether these animals moved throughout the months of their lives. For this strategy, oxygen isotopes have also been analysed, which show the changes in temperature and allow us to determine whether the sample analysed belongs to what they ate during the summer or winter. Thus, by combining these two isotopes, strontium and oxygen, and analysing different times of tooth growth, it is possible to observe seasonal movements of the herd or whether these animals came from a different place and ended up living in the site where they have been found.
But in order to be able to trace this geographical ‘signal’, it is necessary to know not only what signal we expect to find in each archaeological site analysed, but also in the other possible geologies in the Balearic Islands. Otherwise, it would not be possible to understand our results. That's why one of the main tasks has been to extend from 10 to 35 the strontium references available in the Balearic Islands, thus covering all the geologies of Mallorca, Menorca and Formentera.
Results of the study
The results obtained in this study have provided valuable information in several aspects, both at a general level and for each of the sites studied. In summary, it is now confirmed that during the Bronze Age there were local sheep and goat pastures, where
each settlement managed its flock more or less independently, but which at the same time had a fairly free movement throughout the territory both within the island of Menorca and in Mallorca. The exchange of live herds is difficult to detect due to the similarity of the geologies between islands, but in the case of Cala Blanca and S'Illot des Porros there are some indicators that suggest a possible exchange between these two islands. It should also be noted that, at least to date,
the arrival of animals from outside the Balearic Islands has not been determined in either of the two periods.
In relation to the comparison between islands, in Mallorca it is worth noting that the sites that show a greater movement of animals are those that functioned as meeting points or possible exchange points, such as the Cueva del Camp del Obispo or s'Illot des Porros. On the other hand, the animals in the settlements would have had a local pasture with reduced mobility. In contrast, in Menorca, a different livestock-raising practice can be detected, probably associated with the north-south binomial and a shorter distance between grazing areas. In fact, the pastures of the Menorcan sheep and goat flocks show greater mobility with no distinction between the two chronologies studied.
The data from the Talayotic period of this study are scarce and it seems that neither in Mallorca nor in Menorca are major changes in flock management detected, so it is necessary to carry out a more in-depth study to be able to affirm this. Finally, the study of the geological availability of strontium has established a more solid basis for its presence in the Balearic Islands, which will be of great help in future works.
This study is part of the project ‘The construction of cultural landscapes during the Bronze Age in the Balearic Islands’ (PRD2018/19) funded by the Directorate General for University Policy and Research of the Balearic Government with the Tourist Tax fund (ITS 2017-006) carried out by the ArqueoUIB Research Group of the University of the Balearic Islands. This publication shows the results of more than 3 years of work that has been possible thanks to the collaboration of 24 researchers from 15 different institutions, as well as other people who have contributed with their work to make this work possible.
Author: Lua Valenzuela Suau. Postdoctoral fellow Margarita Salas. Department of Historical Sciences and Theory of the Arts. ArqueoUIB Research Group. University of the Balearic Islands