Let's escape our caves and, quite literally, spend more time philosophizing in the great outdoors.

Al-Muqrinat cave was first visited by the Italian researcher Umberto Paradisi in June 1964, after he was told by the locals of its location. Paradisi in turn conducted the first field study in the region. Archaeologist Charles McBurney made some observations on the study particularly with respect to the history of the engravings and the site was referred to as being the first discovery of rock art in the Green Mountain. No further field studies were carried out until 2001, when Libyan student Saad Buhajar investigated the site as part of his master's research. This article is the result of intermittent visits to the cave over a period of 27 years and provides the accurate descriptions of findings including new discoveries.

Dates from the mammal fauna of Crystal Caverns, El Dorado County, California confirm that it is a Pleistocene deposit from the Last Glacial Maximum. Results indicate it is similar in age to other comparable California caves and has a high degree of time averaging.

The Romanelli Cave in south-east Italy is an important reference point for the so-called ‘Mediterranean province’ of European Upper Palaeolithic art. Yet, the site has only recently been subject to a systematic investigation of its parietal and portable art. Starting in 2016, a project has recorded the cave's interior, discovering new parietal art. Here, the authors report on a selection of panels, featuring animal figures, geometric motifs and other marks, identifying the use of different types of tools and techniques, along with several activity phases. These panels are discussed with reference to radiocarbon dating of nearby deposits, posing questions about chronology, technology and wider connections between Upper Palaeolithic cave sites across western Eurasia.

During each Heinrich stadial (HS), temperatures in southern Europe typically dropped several degrees during several hundred to few thousand years. We have developed a one-dimensional thermal conduction model that transfers the typical surface temperature anomaly of a HS to a series of hypothetical underlying caves. The results show that with increasing depth, the thermal anomaly is attenuated, the lag time increases, and the signal structure experiences larger modifications. The model suggests that in most cases, it is not acceptable to assume a synchronous thermal variability and similar average temperature values between the surface atmosphere and the cave interior at millennial timescales. We also simulated the thermal impact of the modeled HS on speleothem δ18O records. The outputs of most model scenarios suggest that temperature changes associated with the HS produce δ18O anomalies capable of contributing significantly or even decisively to the speleothem isotope variability. Therefore, despite controls other than temperature often being considered more important when interpreting Pleistocene speleothem δ18O records in temperate climates, this research suggests that temperature is expected to be one of the major controls of δ18O values in most cave sites outside the tropics and should be included as a significant parameter affecting Pleistocene speleothem δ18O records.

The scarcity of Romano-British human remains from north-west England has hindered understanding of burial practice in this region. Here, we report on the excavation of human and non-human animal remains1 and material culture from Dog Hole Cave, Haverbrack. Foetal and neonatal infants had been interred alongside a horse burial and puppies, lambs, calves and piglets in the very latest Iron Age to early Romano-British period, while the mid- to late Roman period is characterised by burials of older individuals with copper-alloy jewellery and beads. This material culture is more characteristic of urban sites, while isotope analysis indicates that the later individuals were largely from the local area. We discuss these results in terms of burial ritual in Cumbria and rural acculturation. Supplementary material is available online (https://doi.org/10.1017/S0068113X20000136), and contains further information about the site and excavations, small finds, zooarchaeology, human osteology, site taphonomy, the palaeoenvironment, isotope methods and analysis, and finds listed in Benson and Bland 1963.

Invertebrates living in underground environments often have unusual and sometimes unique adaptations and occupy narrow ranges, but there is a lack of knowledge about most micro-endemic cave-dwelling invertebrate species. An illustrative case is that of the flatworm Dendrocoelum italicum, the first survey of which was performed 79 years after its description. The survey revealed that the underground stream supplying water to the pool from which the species was first described had been diverted into a pipe for human use, thus severely reducing the available habitat for the species. Here we describe the results of what we believe is the first habitat restoration action performed in a cave habitat for the conservation of a flatworm. The water-diverting structure was removed, with the involvement of local protected area administrators, citizens and volunteers from local organizations. The intervention resulted in the restoration of a large, stable pool inside the cave, thus creating an optimal habitat for this threatened planarian, with increased availability of prey and a stable population. This report of habitat restoration for a neglected invertebrate offers insights for the protection of other micro-endemic species.

A long radiometrically dated oxygen isotopic record of continental climatic variations since the penultimate glaciation was obtained from a stalagmite deposited in a sealed cave in Jerusalem. This record shows that speleothems have the potential of assigning dates to long- and short-term climatic events, with possible refining of Milankovitch tuning of ice and marine records which themselves are not datable. Short-term (∼1000-yr) events are very significant in the region, reaching ∼50% of glacial/interglacial fluctuations. The Mediterranean Sea was the most probable source of local precipitation throughout the last glacial cycle.

Recent explorations in Cueva Charles Brewer, a large cave in a sandstone tepui, SE Venezuela, have revealed silica biospeleothems of unprecedented size and diversity. Study of one — a sub-spherical mass of opaline silica — reveals a complex, laminated internal structure consisting of three narrow dark bands alternating with two wider light bands. Uranium–thorium dating has produced 3 stratigraphically correct dates on the light bands from 298 ± 6 (MIS 9) to 390 ± 33 ka (MIS 11). U concentration is only 30–110 ppb. Initial 234U/238U ratios are high and increase over time from 1.8 to 5.3. Growth rate is very low, the fastest, at 0.37 ± 0.23 mm/ka, in MIS 9. Trace element and heavy metal content of the dark bands is distinctly higher than that of the light bands. It is hypothesized that the dark and light bands correlate with drier/glacial and wetter/interglacial periods, respectively, and that this sample probably began to grow in MIS 13. The cave is in a region that straddles a regionally important ecotone: the speleothem isotopic and trace element variations may preserve a useful paleoclimatic signal. This is the first published suite of U–Th dates from a single silica speleothem and the longest Quaternary record for this region.

Su Fossu de Cannas (SFC) cave is one of several known cavities in the Sadali plateau in Sardinia, Italy. The evolution of the cave is the result of complex erosional and deposital processes that occurred during the Neogene and Quaternary. A fossiliferous cemented conglomerate, containing various deer remains, now forms the ceiling of a cavity (tunnel). The faunal remains belong to a large cervid, which show some morphological affinity with large deer that have an endemic Sardinian lineage (Praemegaceros sardous — Praemegaceros cazioti). Palaeoecological data based on some peculiar features and the large size of the SFC deer suggest that it is the most primitive Megacerine found in Sardinia to date, and the first representative of the endemic lineage. The 450 ka U—Th age for the flowstone capping the fossiliferous layer defines: the end of sedimentation in which Sadali deer remains are preserved; and the dispersal from the mainland of the ancestor of the endemic Sardinian Megacerini. Stratigraphic and micromorphological analyses of the cave deposits allow the reconstruction of the timing of the cave’s development throughout the Pliocene to the Holocene.

Deforestation and forest fragmentation are contributing to declines in crop pollinator populations worldwide. Several studies have examined the impact of forest proximity on plant pollination ecology, but concentrated on single crop species. However, it can be more informative to investigate multiple crop and pollinator species in a community, because different pollinator groups may respond differently to forest distance. We evaluated flower visitor diversity, visitation frequency, and fruit set for three crop species (rambutan, durian and mango) in 10 pairs of mixed fruit orchards. Each pair consisted of one orchard near to (< 1 km) and one orchard far from (> 7 km) the forest edge. Rambutan fruit set was significantly influenced by distance to forest. The main visitors of rambutan flowers were stingless bees. In contrast, the dominant visitors to durian and mango flowers were nectarivorous bats and flies, respectively, and the fruit set of these crops were not significantly influenced by distance to forest. However, durian fruit set was negatively affected by distance to the nearest cave inhabited by nectarivorous bats. This study demonstrates that both caves and forests can be important pollinator sources for agricultural crops, and that the dispersal success of pollinators is related to isolation from source habitats. Maintaining forest patches and limestone karsts may provide stepping stones across fragmented landscapes, and attract greater numbers of pollinators to agricultural areas.

International trade of swiftlet nests has affected wild populations of edible-nest swiftlets throughout their range. The white-nest swiftlet Aerodramus fuciphagus of the Andaman and Nicobar Islands lost 80% of its population in the 1990s. Conservation efforts for the species were initiated in 2000, with the active involvement of former nest collectors. To measure the efficacy of protection measures we collected data on the swiftlet, using the nest count method. We monitored annual breeding populations in 28 protected caves on Chalis-ek and one on Interview Island during 2000–2008, and in 168 unprotected caves on Baratang and Interview Islands during February–April 2008. The swiftlet population in protected caves increased by 39%, whereas it declined by 74% in unprotected caves. Nearly 61% of the 152 caves on Baratang Island were abandoned by the swiftlet during 1997–2008. This study highlights the importance of extending protection to the unprotected caves on the Andaman and Nicobar Islands.

The archaeological exploration of a cave in the southern Caucasus revealed evidence for early social complexity, ritual burial and wine-making in the early fourth millennium. The marvellous preservation of wood, leather and plants offers a valuable contrast to the poorer assemblages on contemporary tell sites. The authors make the case that the Areni-1 cave complex indicates connections between the urbanisation of early Mesopotamia and the Maikop culture of south Russia.

Sacred sites, particularly in forests, often form unofficial protected areas because their biodiversity is preserved and protected by the local people looking after the sites. Here, we survey the biodiversity of the Three Sisters Cave complex, a sacred site or kaya in a fragment of East African coastal forest in south-east Kenya. We show that, despite the tiny size of this non-gazetted forest reserve, it contains many of the threatened species of both flora (121 species) and fauna (46 species) representative of Kenya's coastal forest. Following the overexploitation and widespread destruction of coastal rainforests in Kenya, such sacred sites represent key biodiversity hotspots as well as forest islands in the now largely deforested coastal plain. Other non-gazetted forest sacred sites may represent undocumented sources of biodiversity that may contribute towards conservation of this threatened coastal habitat.