The effect of visitor density and interaction on the behavior of four ray species (Hypanus sabina, Hypanus say, Pseudobatos lentiginosus, and Rhinoptera bonasus) housed in an aquatic touch pool

Human-Animal Interactions (HAI) in zoological institutions are thought to be important in helping visitors to establish a connection with animals and thus making them more likely to contribute to conservation efforts. However, animals can respond to visitor interaction in both negative and positive ways. The growing focus on animal welfare in zoological institutions emphasizes the need for assessing different environmental inputs, including visitor interaction, and how these inputs influence behavioral outputs associated with welfare. A touch pool exhibit presents a novel interactive experience that allows visitors to directly interact with various aquatic species, including elasmobranchs, whose conservation has important implications for the marine ecosystem. Yet there is little information on how interactive experiences impact the welfare of elasmobranchs in touch pools. This study assessed the role of visitor density and activity on the behavior of four different elasmobranch species in a touch pool exhibit. Experimental conditions were implemented to assess how regulating visitor interactions with the animals impacted elasmobranch behavior. Higher visitor numbers, frequencies of interaction, and frequencies of intense interactions from visitors were correlated with higher instances of aggression and negative reactions to visitors from the animals. Findings showed that the presence of food also had a significant effect on the occurrence of aggression and negative reactions, and it is likely that increased food provisioning during the experimental conditions lead to higher rates of aggression and negative reactions than expected. This study proposes the regulation of visitor density, interactions, and feedings to reduce aggression and negative reactions among elasmobranchs in a touch pool exhibit. Results indicated that the pro-social Rhinoptera bonasus was much more likely to engage in interactions with visitors and was more likely to show aggressive behaviors compared to the other three less-social species. Studies of elasmobranchs in captivity and in the wild have shown that species can aggressively compete for valued resources, and there is the potential for this competition to negatively affect health and well-being of elasmobranchs if dominant species or individuals repeatedly target the same animals. Findings demonstrate that species compatibility is an important consideration for touch pool exhibits, and cross-institutional comparison should be carried out to determine if pro-social elasmobranch species are better suited to interactive experiences compared to less-social species

Enigmatic plant-working tools and the transition to farming in the Rhine Meuse Delta

Material Culture Studie

Art by firelight? Using experimental and digital techniques to explore Magdalenian engraved plaquette use at Montastruc (France)

Palaeolithic stone plaquettes are a type of mobiliary art featuring engravings and recovered primarily from Magdalenian sites, where they can number from single finds to several thousand examples. Where context is available, they demonstrate complex traces of use, including surface refreshing, heating, and fragmentation. However, for plaquettes with limited or no archaeological context, research tends to gravitate toward their engraved surfaces. This paper focuses on 50 limestone plaquettes excavated by Peccadeau de l’Isle from Montastruc, a Magdalenian rockshelter site in southern France with limited archaeological context; a feature common to many art bearing sites excavated across the 19th and early 20th Centuries. Plaquette use at Montastruc was explored via a programme of microscopy, 3D modelling, colour enhancement using DStretch©, virtual reality (VR) modelling, and experimental archaeology, the latter focusing on limestone heating related to different functional and non-functional uses. While the limited archaeological context available ensures the results remain only indicative, the data generated suggests plaquettes from Montastruc were likely positioned in proximity to hearths during low ambient light conditions. The interaction of engraved stone and roving fire light made engraved forms appear dynamic and alive, suggesting this may have been important in their use. Human neurology is particularly attuned to interpreting shifting light and shadow as movement and identifying visually familiar forms in such varying light conditions through mechanisms such as pareidolic experience. This interpretation encourages a consideration of the possible conceptual connections between art made and experienced in similar circumstances, such as parietal art in dark cave environments. The toolset used to investigate the Montastruc assemblage may have application to other collections of plaquettes, particularly those with limited associated context

Being Ritual in Mesolithic Britain and Ireland : Identifying Ritual Behaviour Within an Ephemeral Material Record

Acceptance of ritual as a valid interpretation of Mesolithic behaviour has slowly emerged over the past decade; the ‘silly season’ heralded by Mellars (Antiquity 83:502–517, 2009) has not materialised, though in Ireland and Britain difficulties persist in defining what might constitute ‘ritual’ away from the graveside. New discoveries from both the development-led and academic sectors enable Mesolithic archaeologists to better establish which elements of the archaeological record can be interpreted as ritual. This paper seeks to identify further strands of ritual behaviour, incorporating evidence from sites without organic remains. We consider the evidence for ritual at the site and feature scales, and in the special treatment of objects—an often overlooked body of data in understanding ritual. Thus the material signature of ritual will be questioned, and ways in which Mesolithic ritual can be rehabilitated and expanded will be explored

Artists on the edge of the world : An integrated approach to the study of Magdalenian engraved stone plaquettes from Jersey (Channel Islands)

The Upper Palaeolithic is characterised by the appearance of iconographic expressions most often depicting animals, including anthropomorphic forms, and geometric signs. The Late Upper Palaeolithic Magdalenian saw a flourishing of such depictions, encompassing cave art, engraving of stone, bone and antler blanks and decoration of tools and weapons. Though Magdalenian settlement exists as far northwest as Britain, there is a limited range of art known from this region, possibly associated with only fleeting occupation of Britain during this period. Stone plaquettes, flat fragments of stone engraved on at least one surface, have been found in large quantities at numerous sites spanning the temporal and geographical spread of the Magdalenian, but they have been absent so far from the archaeological record of the British Isles. Between 2015 and 2018, ten fragments of stone plaquettes extensively engraved with abstract designs were uncovered at the Magdalenian site of Les Varines, Jersey, Channel Islands. In this paper, we report detailed analyses of these finds, which provide new evidence for technologies of abstract mark-making, and their significance within the lives of people on the edge of the Magdalenian world. These engraved stone fragments represent important, rare evidence of artistic expression in what is the far northern and western range of the Magdalenian and add new insight to the wider significance of dynamic practices of artistic expression during the Upper Palaeolithic

Dielectric Replica Measurement : A New Technique for Obtaining the Complex Permittivity of Irregularly Shaped Objects

Dielectric measurements provide valuable information about the properties of materials, and could be used to classify and identify the source of objects in fields such as archaeology. Current methods of identification are all partly destructive, so an innovative electromagnetic method developed by the authors, based on resonant cavity perturbation (RCP), provides an attractive, non-destructive alternative. A problem with traditional RCP is that the changes in frequency and Q-factor vary with the object's shape; however, we overcome this by creating a replica of the object, from a material whose dielectric properties are known. Then, by combining three separate perturbations with orthogonal field directions, due firstly to the object and then to its replica, we eliminate the shape dependency, and thus determine the object's dielectric constant and loss factor. After developing the theory of this novel DRM technique, we demonstrate the principle using a set of geometric shapes made in both polytetrafluoroethylene and a 3D printed material. Further measurements then enable second-order terms to be included in the model, improving its accuracy. Finally, DRM is shown to be capable of distinguishing two irregularly shaped objects of different materials. Potential applications of DRM include determining the provenance of pottery, glasses and flints, and distinguishing ivory from bone. These would be of interest to customs and environmental agencies, as well as museum curators and archaeologists

Spatial organisation within the earliest evidence of post-built structures in Britain

This paper explores tool-using activities undertaken in and around the earliest known evidence of post-built structures in Britain. Microwear results associated with at least three structures identified at the Early Mesolithic site of Star Carr, North Yorkshire, are examined as a means of identifying activity zones associated with the diverse stone tools used to process a variety of materials (e.g. wood, bone, antler, plant, hide, meat, fish). With 341 lithic artefacts analysed, this research represents the first microwear study focused on the post-built structures at Star Carr. A combination of spatial and microwear data has provided different scales of interpretation: from individual tool use to patterns of activity across the three structures. Different types of tool use observed have aided interpretations of possible activity areas where objects were produced and materials were processed. Zones of activity within one of the structures suggest that the working of some materials was more spatially restricted than others; even where there are high densities of flint deposition, spatial patterns in tool-using activity were observed. From this, it is interpreted that social norms and behaviours influenced the spatial organisation of different spaces. Our results demonstrate the importance of combining microwear analysis with GIS to explore function and variability in the use of Mesolithic structures - providing new insights into their role as social spaces

Material and Sensory Experiences of Mesolithic Resinous Substances

Mesolithic resinous adhesives are well known for their role as hafting mastic within composite technologies, yet it is increasingly clear that their usage was more diverse than this. Birch-bark tar has been recovered from Mesolithic contexts as chewed lumps linked to medicinal treatment of toothache and oral diseases, and as a decorative element on ornaments and art objects; and an amorphous resinous substance possibly derived from pine or spruce resin has been found within a burial context. This diversity of applications suggests that resins and tars may have been understood in different ways which did not always privilege their mechanical functionality. To underscore the limited archaeological perspective of conifer resins and tars as hafting agents, we draw on data sourced from a wide range of ethnographically documented societies, demonstrating the array of economic and social functions these materials have for contemporary hunter-gatherer groups. Using archaeological case studies, we illustrate how a deeper understanding of the material and sensory properties of resins and tars, and the trees from which they are derived, opens new insights into the diverse roles resinous materials performed within Mesolithic worldviews

An experimental study of wet-cooking in organic vessels: implications for understanding the evolution of cooking technologies

The ability to control and direct fire is a major evolutionary step in the human story. The development of aceramic cooking technologies is less well understood as they rarely survive in the archaeological record. However, inferential evidence such as fire-cracked rocks, earthen pits and heated bones suggest a variety of cooking methods were used prior to the invention of ceramics. Yet there is a paucity of experimental evidence testing the efficacy of perishable organic containers in tasks involving their use with heat. The study presents experimental results of organic containers and their use for heating water related to cooking. Containers were made from deer hide and pig stomach and water was heated using two different techniques: placing the container directly above a fire and placing hot stones into the container. The results suggest that different organic containers and heating types could attain and maintain a sub-boiling cooking temperature; however, not all could reach boiling point. It is argued that these sub-boiling methods may be as, or perhaps more, desirable than boiling, with potential implications for the development of vessels prior to the adoption of ceramics