The archaeological site of Castro de Chibanes is a fortified settlement, located in Serra do Louro (Palmela, Portugal; Figure 1). It is located at the top of the hill, naturally defended by a scarp to the south and overlooking the Barris valley. Below the site are exceptionally fertile lands watered by the nearby Ribeira da Corva stream. The site is also in close proximity to the Tagus River and the Atlantic Ocean.

The geographical location of the site offers plenty of exploitable resources, making it an exceptional place to live. Consequently, it was occupied across three distinct periods: Early Chalcolithic/Late Bronze Age (3^rd millennium BC); Iron II Period (4^th/3^rd century – 2^nd century BC); and the Roman period (second half of the 2^nd century – 1^st century BC).

The site was identified and first excavated by António Inácio Marques da Costa, in 1906, with the recognition of structures and material culture spanning the Neolithic to the Roman period (Silva & Soares 1997: 33–39). Since 1996, the researchers Carlos Tavares da Silva and Joaquina Soares have been excavating and studying the site. As a result, four distinct phases of the 3rd millennium BC have been proposed, based on the decorative motifs of pottery (Figure 2) and stratigraphic occupation of the site, in combination with radiocarbon dates (Silva & Soares 2012: 74–78; Silva & Soares 2014: 159–164):

In this article, preliminary data are presented, uniquely focusing on the analysis of fauna from the earliest archaeological phase at Castro de Chibanes; Phase IA (Early Chalcolithic) with the aim of gaining a more detailed understanding of the first Chalcolithic communities of the Portuguese Estremadura, particularly the site of Castro de Chibanes. Phase IA can be divided into two: Phase IA1, characterised by the construction of the North fortification wall VIIIb (2904–2573 cal BC 2σ); and Phase IA2, featuring the collapse of the surrounding walls, as well as domestic buildings, followed by fires (2675–2277 cal BC 2σ and 2639–2468 cal BC 2σ; Silva & Soares 2014:111–117).

An interesting and well preserved assemblage of faunal remains were collected during excavations, comprising mainly mammals and a small amount of bird and fish remains. All bone fragments were examined, counted and recorded with sample provenance (year, section, stratigraphic unit, etc.); bone fragment (taxa, element, portion, side, fusion); taphonomic data (animal, human or geo-chemical modifications); osteometric measurements; and other relevant comments.

Taxonomic identification depended predominantly on Schmid (1972), Barone (1976) and France (2009) for mammal determination; whilst for birds, Olsen (1996) was the main guide. Finally, all the uncertainties were clarified with the help of the osteological collection of the Archaeoscience Laboratory of Direção-Geral do Património Cultural (DGPC) in Lisboa and other specific bibliography relating to detailed species, as Zeder and Lapham (2010) for distinguishing sheep and goat or Heintz (1970) for bovines and cervids.

Age at death of mammals was calculated based on two distinct methods: For appendicular bones, three fusion stages of the epiphyses with respective diaphyses were considered: unfused for juveniles; partially fused for young adults; and fused for fully grown adults. For tooth analysis, tooth eruption and wear was examined considering Ageing and Sexing Animal Bones from Archaeological Sites (Wilson et al. 1982) and Payne (1973), particularly for sheep and goats.

Taphonomic matters were recorded considering the procedures laid out by Lyman (1994) and Reitz & Wing (2008).

Quantification was made using the Minimum Number of Individuals (MNI) and the Number of Identified Specimens (NISP). The Minimum Number of Animal Units (MAU) was not considered due to the small size of the sample.

Osteometric measurements were taken on mammal and avian bones according to von den Driesch (1976) parameters, as well as Davis (1996) for sheep and goats.

The analysed assemblage contained a total of 858 faunal remains, with a NISP of 257. Mammals form the majority of the dataset; (92% of the sample, n = 791), followed by fish (7%, n = 59) and birds at only 1% of the remains (n = 8) (Table 1).

Excluding the absence of cervids in phase IA2, there was no significant difference between levels of Phase IA1 or Phase IA2, even though the first results from construction and domestic realities and the second is the outcome of an assumed earthquake and fire contexts (Silva & Soares 2014: 116–137).

Aiming for a better understanding of the faunal assemblage and its archaeological context, taphonomic markers (agents, processes and effects) were considered while analysing the bones. We were looking for anthropic modifications (such as fire alteration from cooking/roasting and butchery marks), animal modifications (such as carnivore gnawing, puncture marks and partially digested bone) and geo-chemical modifications that could weather, erode or abrade bones.

From the 858 faunal remains recorded, only 8% of them have butchery marks in consequence of carcass and food processing. Additionally, 41% of the bones have spiral fractures, implying their breakage while fresh, probably to enable cooking and bone marrow extraction, through boiling. The majority of the faunal assemblage is therefore a result of consumption.

On the other hand, 86% of the bones demonstrate weathering, which may suggest repeated discarding of the bone fragments on the surface, rather than into a designated rubbish pit.

Burning modifications were identified on 8.74% of the remains (n = 75), with a large fraction of them charred, however light brown and calcined bones were also identified. As the remains were probably scattered on the surface, it is difficult to differentiate between the burning marks as deliberate, anthropogenic measures (such as cooking), or resulting from accidental fires.

Livestock comprises the majority of the Phase IA1 and IA2, Early Chalcolithic Castro de Chibanes faunal assemblage, showing a fully sedentary population with husbandry as a central activity for human consumption patterns.

Pigs, sheep and goats form the clear majority of the remains from Chibanes, mainly for consumption purposes, with similar percentages and an equal MNI (n = 5). Considering the published data (using mostly NISP frequencies), at other Chalcolithic sites from Estremadura, caprines are usually identified as the dominant species, in contrast with the prevalence of Sus in Alentejo. Nevertheless, taking into consideration only the pre-Bell Beaker period, although pigs are in fact predominant in the Chalcolithic archaeological sites from Alentejo, in Estremadura the percentages of sheep/goats versus pigs are very similar (Valente & Carvalho 2014: 9, Figure 5). The same happens in Chibanes as it is also not possible to determine which species overcome the other as NISP and MNI % show great similarities.

Due to the estimation of death, it appears that suids were used as the main protein suppliers, slaughtered while still juvenile, with the consumption of meat as the main goal. On the other hand, a high percentage of caprine were also killed while juvenile which entail not only its exploitation for meat, but also the indirect evidence of milk production. Both species are straightforward to maintain and raise as they don’t need large herding spaces and are easily and economically fed.

On the top of the meat consumption are also the lagomorphs, since rabbits, as pigs and sheep/goat, have at least five individuals present in the collection. Although rabbits provide fewer calories, they are abundant and easy to hunt.

The low range of cervids (Cervus elaphus and Capreolus capreolus) in Phase IA1 and their disappearance from the archaeological record during Phase IA2 may entail a growing exploitation of domestic animals and a subsequent sedentary lifestyle, contrasting with a decrease on the need of hunting for food. This trend is also recognized at other fortified sites from Estremadura like Leceia, Penedo do Lexim or Zambujal, where the percentages of wild species is extremely low (Valente & Carvalho 2014: 9).

Conversely, it seems that domestic cattle are scarce and were likely used for labour traction. Some bovine faunal remains appear to be quite large and bulky, which may represent hunting and subsequent consumption of aurochs, but more data is needed to elucidate this assumption.

In general, the faunal collection is very similar to other known assemblages from archaeological sites of Estremadura within the same timeframe. It shows a “typical” range of species, with similar taxonomic abundances. It is noteworthy that though equid frequencies are frequently low in Chalcolithic sites, in Castro de Chibanes no bones from this taxa were identified.

With low percentages, the presence of birds and fish are interpreted as a result of consumption, as well as a direct evidence of marine fishing and hunting activities. These wild resources were widespread and it makes perfect sense to make use of them as a complement to the diet of these populations. Additionally, birds were often relevant not only for its nutritional value but also for its bones and tendons as raw material for diverse tools (Pimenta & Moreno 2009:12).

As the assemblage comprises a rather small number of identified specimens, more data is needed to verify some of the assumptions made here.