Pastoral activities in the northeastern Pyrenees increased substantially during the Bronze Age, raising the question of the modalities of occupations in zones where the snow cover limited access to grasslands for a significant part of the year. The present study explores how stable isotope analysis may characterize the adaptation of husbandry to mountain environments through herding strategies, including the vertical mobility of livestock. It also addresses the broader issue of the occupation of territories by Bronze Age communities in the Western Mediterranean area, focusing on possible links between coastal plains and mountainous areas. For this purpose, sequential stable carbon and oxygen isotope analyses were conducted on caprines' teeth from the mountain site of Llo (Pyr en ees-Orientales, 1630 m asl, Middle Bronze Age) and the permanent coastal site of Portal-Vielh (H erault, 0 m asl, Late Bronze Age). An exploratory analysis was also conducted on modern sedentary and transhumant ewes to investigate the effect of altitudinal mobility on enamel oxygen isotope values. The range of d 18 O values measured in modern and archaeological caprines raised in mountain zones was lower than the one measured in the lowland caprines, while no significant difference could be observed in the range of d 13 C values. Co-variations between d 13 C and d 18 O sequences reveal the most information. The positive correlation observed in all instances at low elevation sites was not the leading pattern at Llo, where a variety of schemes could be observed, including opposite d 13 C and d 18 O sequences. This opposition could not be explained by a reversal of the d 18 O cycle due to vertical mobility. Other causes could involve changes in the pattern of variation of d 13 C values, potentially linked to human responses to the local constraints, including vertical mobility and/or foddering. Portal-Vielh delivered a fully lowland signal. At Llo, although a full adaptation to a mountain environment seems clear, the question of the vertical mobility of the livestock cannot be resolved at the moment. Most importantly, Llo was characterized by a high inter-individual variability in the co-variation of d 13 C and d 18 O profiles, reflecting great plasticity of the husbandry practices on the inter-annual scale. This could have been a key to the adaptation to these marginal environments. The apparent disjunction between the coastal and mountain settlements, as far as herd trajectory is concerned, must be reaffirmed by further investigations in a larger number of sites.

<p>Archaeologists working in high altitude-zones in the Alps where faunal remains were absent have until relatively recently, been reliant on palynology in order to infer the probable presence of pastured animals. The development of sedimentary ancient DNA (sedaDNA) analysis has changed this. We are now able, if taphonomic conditions permit, to identify the presence and absence of specific domesticated animals as well as changes in vegetation communities that were a consequence of pastoral activity. Over the past decade, lake sediment DNA has been used by an increasing number of studies to trace past agricultural activities, human presence and landscape changes.</p><p>More recently, lake sedaDNA sequencing has proven applicable to investigate the relative impact of human activities, such as transhumance pastoralism, on the vegetation in the catchment of lakes in the Western French Alps and the domestic species used at different time periods. Thus, providing a new outlook on the anthropogenic effect on alpine landscapes.</p><p>Our use of sedaDNA is one element in a project designed to elucidate the evolution of transhumance in the Western Alps. While the sequential isotope analyses from domesticated herbivore teeth facilitate our comprehension of seasonal pastoral mobility, the sedaDNA complements this work via its potential for inferring which pastures were frequented and the effect of livestock presence on these environments. This combined approach can demonstrate not only the existence of pastoral practises in the region, but also reconstruct the movement patterns as well as the direct impact of transhumance pastoralism in the Western Alps in a wide chronological and spatial frame.</p><p>With the application of advanced bioinformatic techniques, we combine previous data on past and present vegetation with our findings. The genetic data was obtained through the established method of metabarcoding, which is a relevant tool for reconstructing palaeoenvironments. Using the same approach with additional quantitative PCR analysis for mammalian sedaDNA offers even more detailed insights into the presence and possible abundance of domestic species in the lake catchment area.</p><p>This application can demonstrate the potential of sedaDNA in reconstructing palaeoenvironments and its relevance in conceptualising long-term ecosystem changes relating to human and non-human agencies.</p>