Adaptability, resilience and environmental buffering in European Refugia during the Late Pleistocene: Insights from La Riera Cave (Asturias, Cantabria, Spain)

Abstract

The Upper Palaeolithic in Europe was a time of extensive climatic changes that impacted on the survival and distribution of human populations. During the Late Glacial Maximum (LGM), southern European peninsulas were refugia for flora, fauna, and human groups. One of these refugia, the Cantabrian region (northern Atlantic Spain), was intensively occupied throughout the Upper Palaeolithic. Characterising how climatic events were expressed in local environments is crucial to understand human and animal survival. La Riera Cave (Asturias) has a rich geo-cultural sequence dating between 20.5kyr BP to 6.5kyr BP and represents an ideal location in which to explore this. Stable isotope analysis of red deer and ibex is used alongside other environmental and climatic proxies to reconstruct Late Upper Palaeolithic conditions. Results show that during the LGM, ibex adapted their niche to survive, and became a major prey species for humans. The diverse environmental opportunities offered in the high-relief and coastal environs of La Riera may help to explain the high human population levels in the Cantabrian Region throughout the Late Upper Palaeolithic. Despite fluctuating conditions, herbivores and humans had the flexibility and resilience to adapt, demonstrating the importance of southern European refugia for the survival of different species.The settlement of Europe during the Last Glacial (MIS2) period (c.30-10kyr BP) was directly affected by the climate which resulted in cycles of expansion and contraction of populations, linked to the ebb and flow of ice sheets 1-3 . Central and northern Europe during the Last Glacial Maximum (LGM) (c. 21-18kyr BP) were mostly covered by ice sheets or polar desert that pushed populations into the south, with Iberia and southwestern France, Italy and the Balkan peninsulas acting as refugial regions. Within these locations less drastic temperatures, associated with milder conditions, facilitated survival of a variety of plant and animal species 4-13 . Of these areas, the Cantabrian region, which occupies the northern Atlantic coast of the Iberian Peninsula (Fig. 1) has been demonstrated to have been a genetic refuge for salmon 14 , red deer 15 and humans 16,17 . At least 55 archaeological sites dating to the Solutrean (24kyr BP) have been recorded in the Vasco-Cantabrian region, concurrent with a large increase in the number archaeological occupation levels recorded within many sites 13,18 , indicative of a shift of surviving populations in Europe to the region 10,11,[19][20][21] . During the Magdalenian (c. 17-11.5kyr BP), a further population expansion is observed with a dramatic increase in the number of archaeological sites recorded, linked to ameliorated climatic conditions 21,22 as identified in proxies such as ice and marine cores. This region has been described as a "dynamic cultural center in the Upper Palaeolithic world of western Europe" 23 , as reflected by and, in part, due to its extensive and rich cave art and portable art. These phenomena clearly demonstrate the importance...

Human forager response to abrupt climate change at 8.2 ka on the Atlantic coast of Europe

“…Given the higher levels of human predation on littoral resources observed during this time at El Mazo, it seems highly likely that the northern Iberian coast, a less climatically sensitive region than the nearby mountain areas 46 and Ebro river basin 54 , 55 , provided a refuge for humans moving from inland regions. A similar scenario has also been argued for this region during the Last Glacial Maximum 58 when northern Iberia became a refugium for forager groups. Population migrations from adjacent areas are also in agreement with the growing presence of geometric microliths seen in northern Iberia from ca.…”

New human remains from the Late Epigravettian necropolis of Arene Candide (Liguria, northwestern Italy): Direct radiocarbon evidence and inferences on the funerary use of the cave during the Younger Dryas

“…Bocchetta di Altare and Colle di Santa Libera), which -considering the high precipitation and low altitude of glaciers during the Younger Dryas in the Maritime Alps (Ivy-Ochs et al, 2009;Spagnolo and Ribolini, 2019;Rea et al, 2020) e would most likely have been the first passages allowing access to the Po plain for anyone coming from the west. Arene Candide was therefore at the crossroad between the glacial refugia of hunter-gatherers of western and southern Europe (Djindjian, 2015;Jones et al, 2020;Tallavaaraa et al, 2015). The site was also a highly-visible landmark on the landscape, due to the aeolian white sand dune that raised up to its entrance at 90 m a.s.l.…”

Metabarcoding faecal samples to investigate spatiotemporal variation in the diet of the endangered Westland petrel (Procellaria westlandica)

“…Adaptability to different temperatures and availability of resources would be a sign of resilience of the petrel's populations to different environments and can greatly inform the design of conservation plans (Berkes and Jolly, 2002;Jones et al, 2020;McDonnell and Hahs, 2015;Yellen, 1977).…”

“…Because these variations can severely affect populations of marine top predators (Cury et al, 2000; Reid and Croxall, 2001) it is essential to understand their drivers to ensure the conservation of the Westland petrel. Adaptability to different temperatures and availability of resources would be a sign of resilience of the petrels’ populations to different environments and can greatly inform the design of conservation plans (Berkes and Jolly, 2002; Jones et al, 2020; McDonnell and Hahs, 2015; Yellen, 1977).…”