Substantial debate surrounds the relative lack of formal burials in Britain during the fifth century AD, which was a key period of social and economic transition following the withdrawal of the Roman army. Here, the authors argue that the ‘missing fifth century’ may be explained, in part, by the continuation of archaeologically invisible mortuary treatments practised in the preceding Iron Age and Roman period. Compilation of published radiocarbon dates from human remains found in cave and riverine contexts demonstrates that a variety of methods for the disposal of the dead—outside of formal cemeteries—existed in the first millennium AD.

Humans have utilised caves for funerary activities for millennia and their unique preservational conditions provide a wealth of evidence for treatments of the dead. This paper examines the evidence for funerary practices in the caves of Scotland and northern England from the Bronze Age to the Roman Iron Age (c. 2200 bc–ad 400) in the context of later prehistoric funerary ritual. Results suggest significant levels of perimortem trauma on human skeletal remains from caves relative to those from non-cave sites. We also observe a recurrent pattern of deposition involving inhumation of neonates in contrast to excarnation of older individuals.

Trioctahedral smectite is a constituent of Mg-rich carbonate crusts and moonmilks (pasty deposits) in caves of the Guadalupe Mountains of southeastern New Mexico. Energy dispersive X-ray microanalysis of individual crystallites and their aggregates along with the X-ray diffraction analysis indicates that the smectite is probably stevensite. Saponite is likely present in some samples also. The smectite is intimately associated with dolomite crusts and huntite moonmilks in Carlsbad Cavern, Lechu-guilla Cave, and other dolostone caves. Clay particles appear as fibers and films, with aggregates comprising decimicron-sized filamentous masses that envelop crystals of dolomite, huntite, and magnesite. The occurrence of smectite is related to the genesis of the Mg-rich carbonate minerals. In water films, progressive evaporation and carbon dioxide loss results in the sequential precipitation of Mg-rich calcite, aragonite, dolomite, huntite, and magnesite. This sequence of carbonate precipitation removes Ca and greatly increases the Mg/Ca ratio in the solutions. Silica is commonly available probably because of high pH conditions, and consequently, smectite forms in the Mg-rich alkaline environment. Along with the Mg-rich carbonate minerals, opal, quartz, and uranyl vanadates may precipitate with the smectite.

Lechuguilla Cave is a hypogene cave formed by oxidation of ascending hydrogen sulfide from the Delaware Basin. A unique sediment deposit with characteristics suggesting derivation from the land surface, some 285 m above, was investigated. At this location, the observed stratigraphy (oldest to youngest) was: bedrock floor (limestone), cave clouds (secondary calcite), calcite-cemented silstone, finely laminated clay, and calcite rafts. Grain-size analysis indicates that the laminated clay deposits are composed of 59-82% clay-size minerals. The major minerals of the clay were determined by X-ray diffraction analysis and consist of interstratified illite-smectite, kaolinite, illite, goethite, and quartz. Scanning electron microscopy observations show that most of the clay deposit is composed of densely packed irregularshaped clay-size flakes. One sample from the top of the deposit was detrital, containing well-rounded, silt-size particles.

Surface soils are probably the source of the clay minerals. The small amount of sand- and silt-size particles suggests that detrital particles were transported in suspension. The lack of endellite and alunite is evidence that the clays were emplaced after the sulfuric-acid dissolution stage of cave formation. Fossil evidence also suggests a previously existing link to the surface.

Members of an alunite-natroalunite solid solution series occur in intimate association with hydrated halloysite in deposits within caves of the Guadalupe Mountains, namely Carlsbad Cavern and Lechuguilla Cave. The alunite and natroalunite crystals consist of cube-like rhombs; crystal diameters range from 0.5 to 8 µm. This mineral association is found in sediments within bedrock pockets, solution cavity fills, floor deposits and wall residues. Sulfur stable isotope values (δ34S, CTD) for cave alunite and natroalunite are negative [+0.1 to −28.9 per mill (‰); n = 12 and mean = 16.8‰] and are comparable to the cave gypsum and native sulfur values reported by other investigators. The association of alunite/natroalunite with hydrated halloysite in these cave deposits suggests that the cave-forming waters contained significant concentrations of sulfuric acid. Formation of these minerals is related to the excavation of the carbonate rocks that formed Carlsbad Cavern, Lechuguilla Cave and other caves of the Guadalupe Mountains. The sulfuric acid-bearing waters, when exposed to clay-rich sediments, converted clay minerals and quartz to alunite/natroalunite and hydrated halloysite.

The Jamaican flower bat Phyllonycteris aphylla is categorized as Critically Endangered on the IUCN Red List. It is endemic to Jamaica and formerly known only from Stony Hill Cave, where there are an estimated c. 500 individuals. Previously declared extinct twice, its rediscovery in 2010 at Stony Hill Cave marked new hope for the conservation of this important species. Although little is known about its ecology, the species is presumed to be a cave-obligate rooster and to rely exclusively on so-called hot caves, which are defined by high ambient temperatures and low air quality. In March–April 2023, we surveyed bats at seven caves throughout Jamaica. At two of these, Green Grotto Caves, St. Ann, and Rock Spring Caverns, St. Mary, we captured both male and pregnant female P. aphylla. At Green Grotto Caves, we captured 24 P. aphylla, and 66 at Rock Spring Caverns. We believe Rock Spring Caverns to be one of the largest known roosts of P. aphylla. Neither of these sites are hot caves as both are moderated by flowing water, although warmer chambers may be more important to this bat than to other species. Further monitoring of these populations and continued exploration of other potential roosts are vital for the protection of this species.

The occurrence of kerolite in association with various secondary Ca-Mg carbonate mineral deposits (speleothems) was identified in basaltic sea caves on the island of Kauai, Hawaii. Kerolite is the dominant clay mineral in the deposits. X-ray diffraction (XRD) peaks of the kerolite are characteristically broadened indicating its extremely poor crystallinity. Few changes were observed in the XRD patterns of this kerolite when it was subjected to various humidity, temperature and ethylene-glycol treatments. The crystals appear as flaky masses with irregular or jagged edges in scanning (SEM) and transmission electron microscopy (TEM). Electron probe and energy dispersive X-ray (EDX) microanalysis show that the clay material is dominated by Mg-Si-O, with minor amounts of Al and Ca in some samples. The chemical composition, thermal analysis and TEM observations suggest that smaller amounts of an amorphous serpentine-like phase are mixed with the kerolite. Kerolite is often the only mineral associated with poorly mineralized, actively-growing microbial mats in these caves and it is common in completely lithified microbial mats. The latter commonly have microstromatolitic structures with kerolite as a dominant phase. These features suggest that kerolite formation is at least in part a result of microbial activity. The abundant extracellular polymers of the mat-forming bacteria bind and concentrate ions (Mg2+, silica) from solution and serve as nucleation sites for kerolite precipitation. Conditions within the mats also probably lead to formation of Mg-Si-gels, amorphous Mg-silicate precursors and ultimately kerolite. Evaporation of the cave solutions may also contribute to kerolite formation.

The Pertosa Caves, today also known as the Pertosa-Auletta Caves, constitute an important karst system in the Campania region (southern Italy). Crossed by the waters of a river that re-emerges on the surface, they have an overall development of about 3 km. Thanks to the width of the entrance, the excellent location along a natural communication route through the mountains and the natural availability of water directly on the site, the initial part of the cavity was frequented by humans, without interruption, from prehistoric times to the Middle Ages. During the protohistory, in particular, the moment of most marked human presence is recorded in the cave. In this phase an extensive pile dwelling system was built on the waters of the underground river. The system was probably created to make the location, subject to frequent flooding, suitable for human settlement. This structure today constitutes an archaeological unicum not only in Italy but throughout Europe. We briefly analyze its general characteristics providing the results of a radiocarbon dating campaign which allowed to assess the occupation phases of the different contexts and the life span of the wooden artifacts, which came to us in a very good state of preservation. Radiocarbon data allowed to assess the chronological range of the human frequentation of the caves and to date the exceptionally well preserved underground pile dwelling system.

The Paisley Cave archeological site in the Northern Great Basin has provided a rich archaeological record from 13,000 to 6000 cal yr BP, including abundant mammalian coprolites preserved in a well-dated stratigraphy. Here we analyze and contrast pollen from within coprolites and pollen in associated sediments to examine vegetation history and assess whether coprolite pollen provides unique information with respect to the coprolite producer, such as the use of specific habitats, foods, or water sources. We found that the dissimilarity of pollen assemblages between coprolites and associated sediments was greater than the serial dissimilarity between stratigraphically adjacent samples within either group. Serial dissimilarity within types was not greater for coprolites than sediments, as would be expected if there were unique pollen signatures derived from the short period (1–2 days) represented by each coprolite. Compared with sediment pollen assemblages, the coprolites had higher abundances of lighter pollen types, and some individual samples were high in wetland taxa (especially Typha). Our results are consistent with coprolite pollen representing short time periods collected as a mammal moves on the landscape, whereas sediment pollen reflects longer time periods and more regional vegetation indicators.

Large, conglomerate caves in north-eastern Iberia have been significant places since the Neolithic through to historical times; however, their significance during the Palaeolithic has barely been explored. This project is the first systematic study of the use of these iconic geological landmarks among Pleistocene hunter-gatherers.

Limited numbers of high-resolution records predate the Last Glacial Maximum (LGM) making it difficult to quantify the impacts of environmental changes prior to peak glaciation. We examined sediments from Last Canyon Cave in the Pryor Mountains of Montana and Wyoming to construct a >45 ka environmental record from pollen and stable isotope analysis. Artemisia pollen was hyper-abundant at the beginning of the record. Carbon isotope values of bulk organic matter (>40 ka) showed little variation (-25.3 ± 0.4‰) and were consistent with a arid C3 environment, similar to today. After 40 cal ka BP, Artemisia pollen decreased as herbaceous taxa increased toward the LGM. A significant decrease in δ13C values from 40–30 cal ka BP (~1.0‰) established a new baseline (-26.6 ± 0.2‰), suggesting cooler, seasonally wetter conditions prior to the LGM. These conditions persisted until variation in δ13C values increased significantly with post-glacial warming, marked by two spikes in values at 14.4 (-25.2‰) and 13.5 cal ka BP (-25.4‰) before δ13C values dropped to their lowest values (-26.9 ± 0.2‰) at the onset of the Younger Dryas (12.8 ka). These results provide insights into late Pleistocene conditions and ecological change in arid intermontane basins of the Rocky Mountains.

Archaeological reconnaissance and test excavation conducted in south-central Ethiopia reveal the region's rich Stone Age and Holocene archaeology. Ongoing lithic, faunal and dating analyses aim to understand chronological and behavioural contexts of prioritised rockshelters as part of a newly launched project. Speleothems in some of the caves promise high-resolution palaeoclimatic reconstruction.

In the tropics, limestone caves in karstic areas are known for their unique biodiversity. However, many caves remain unstudied and little is known about underlying gradients that determine diversity and biomass in aquatic microhabitats. Here, we sampled zooplankton and benthos in a set of 12 aquatic caves, locally called closed cenotes in Yucatán, Mexico. Our aim was to explain diversity patterns and differences in biomass with particular attention for correlations between bat colony characteristics and other biota. Compared with caves that support photosynthesis, diversity was low with an average of four planktonic and two benthic species in these dark caves. Undetectable phosphorus concentrations in the water suggest this nutrient is limiting. Several associations hint at a potential link between bat abundance and functional guild composition, water quality and aquatic biota. As such, more bats were linked to higher nitrate concentrations. Yet this was not translated to higher invertebrate biomass, probably since phosphorus is limiting. Overall, the trends found in this survey suggest that bats could be important as fertilizers of the caves although mechanistic links that mediate the flux of nutrients need to be confirmed experimentally.

Gypsum evaporites are forming under desiccating conditions in relict cave passages in Mynydd Llangattwg, south Wales. Sulphur isotope compositions of these sulphates indicate that oxidation of diagenetic pyrite in the overlying Millstone Grit is the source of sulphate solutions, rather than dissolution of evaporitic sulphate in the limestones.

Species with specific roosting, foraging or breeding requirements are particularly vulnerable to habitat loss and degradation. For bats, the availability and environmental condition of caves can be a limiting factor. The cave specialist Natalus macrourus (formerly Natalus espiritosantensis) is categorized as Near Threatened on the IUCN Red List but as Vulnerable in Brazil, based on a projected population reduction and a decline in its area of occupancy, extent of occurrence and/or quality of habitat. There is a lack of knowledge about the species’ distribution, natural history and ecology, information that is required for conservation. Using new occurrence data and potential distribution modelling we evaluated the distribution of N. macrourus in Brazil, analysed pressures on and threats to the species, and assessed the species’ conservation needs. Natalus macrourus is positively associated with areas with higher probability of cave occurrence and negatively associated with areas of high variation in mean daily temperature and mean annual rainfall. Areas with high environmental suitability for N. macrourus correspond to only 3% of the potential distribution modelled. We estimate that the species has already lost 54% of its natural habitat and that there is < 35% of habitat remaining in areas with high environmental suitability. We calculated that approximately half of the caves in areas with high environmental suitability are < 5 km from mining operations and only 4% of the species’ potential distribution lies within protected areas. Given the strong association of N. macrourus with caves, it is important to protect these habitats, and we recommend that caves where the species is present should receive immediate protection.

Bat guano deposits are common in the Mammoth Cave system (Kentucky, USA). Paleontological remains associated with these deposits are important records of local landscape changes. Recent excavations in the cave suggest that vertebrate remains in most of these deposits are dominated by Chiroptera. Although no extinct fauna were identified, the presence of a large roost of Tadarida brasiliensis in the Chief City section is beyond the northern extent of its current range suggesting that this deposit dates to an undetermined interglacial period. Stable isotope analyses of Tadarida-associated guano indicate a C3 prey signature characteristic of forested habitat. This was unexpected since this species is typically associated with open environments. Further ecomorphological analysis of wing shape trends in interglacial, Holocene, and historic-aged assemblages indicate that interglacial faunas are dominated by fast-flying, open-space taxa (T. brasiliensis) while late Holocene and Historic assemblages contain more taxa that utilized closed forest or forest gaps.

This fifth date list for the long cultural sequence in El Mirón Cave (Cantabria, Spain) reports on new radiocarbon assays for the Middle Paleolithic and Lower Magdalenian levels, ranging from about >45 to 15 uncalibrated kyr.

The dependence of forest communities on bushmeat as a source of protein and income is a challenge to wildlife conservation in Sub-Saharan Africa. We investigated the use of caves and overhanging rocks as hunting camps and the consequences for breeding grey-necked picathartes Picathartes oreas in the forests of Cross River in south-east Nigeria. We recorded 84 nesting colonies during guided and random searches. We found 14 (16.7%) breeding sites that had been used as hunting camps, with evidence including fire stands, sleeping spots, cooking utensils and drying racks. Fire stands were the most frequently recorded evidence of camping and were found in 11 of the camps. At the 14 breeding sites only two nesting attempts were made by P. oreas during the survey. Thirty-seven nests (c. 95%) recorded in hunting camps were empty and showed no evidence of ongoing or potential breeding activities, suggesting that the nests may have been abandoned. We attributed the low nesting attempt rate to disturbance caused by hunters, who also affected breeding success through direct removal of eggs and fledglings from nests. We encourage conservation education for the protection of P. oreas and other threatened species in the region and recommend strict enforcement of wildlife laws and disciplinary sanctions. Given the role of the forests of Cross River as a critical habitat for several endemic and threatened species, management efforts targeted at improving the integrity of the forest will benefit grey-necked picathartes and other avian species of conservation concern.

Grey seals (Halichoerus grypus) are a species of conservation concern that require Marine Protected Area management and population status assessment under the EU Habitats Directive. Aerial surveys are commonly used to monitor grey seal pup production at their globally important UK colonies. However, in Wales more than half of pups are born in cryptic breeding habitats such as sea caves. These cryptic habitats preclude the use of aerial monitoring methods and necessitate ground-based counts, which are costly in resources. In this study, we compare a ground-based pup production census with a reduced effort plot-sampling survey to estimate pup production, derive a total population size and assess cost effectiveness. Pup production in North Wales was estimated at 91 (95% confidence interval: 70–112) by the plot-sampling design and was a good approximation of the ‘true’ value of 96 derived from the census. The total population size in North Wales was estimated at between 242 and 307 grey seals. The plot-sampling design reduced survey effort by 46% and saved 30% on logistical costs compared to the full census. We outline the suitability of this method as part of a monitoring programme for grey seal pup production and suggest our approach may be applicable to other regions where grey seals use cryptic breeding habitat.