Upper Pleistocene Panthera leo spelaea (Goldfuss, 1810) remains from the Bilstein Caves (Sauerland Karst) and contribution to the steppe lion taphonomy,palaeobiology and sexual dimorphism

Remains of the steppe lion Panthera leo spelaea (Goldfuss) from historical digs in the Bilstein Caves of Warstein (Sauerland, NW Germany) are described. Their age seems to be from the Early Weichselian periods (Upper Pleistocene). Whereas the Bilstein cave was inhabited by cave bears at that time only a few hyena prey remains, were most likely imported into the cave entrance by hyenas. Bite and crush marks on a few bones of Bison priscus, Bos primigenius, Cervus elaphus, a rhinoceros Coelodonta antiquitatis vertebra and even several chewed cave bear bones prove the hyena presence which is similar to other caves in the Sauerland hyena den cave rich region. Additionally some larger wolves subspecies Canis lupusspelaeus bones were found, but only few Crocuta crocuta spelaea remains are present. After taphonomic comparisons to six other hyena and cave bear den caves of northern Germany, this cave can be classified as a cave bear den, which was briefly used by hyenas only for food storage or commuting or cave bear predation site in one part of the Cave. The lion material refers at least to one young adult lioness, one more adult female and two male lions; therefore, at minimum, the remains of four adult individuals are represented. The absence of juvenile lion material, in contrast to cave bear cub remains in the Bilstein Caves, proves that P. leo spelaea did not use this and all other caves in the region to raise their cubs. The bone material from the Bilstein Caves would prove the same hyena-lion antagonism conflict being recently proven for the Perick Caves, Balve Cave or Martins Cave well. Other situations in caves such as the Keppler Cave and the Bilstein Cave initially show the more complex taphonomic situation of lion remains in European caves, especially in cave bear dens, where they seem to have hunted periodically cave bears, such as it is already proven for hyenas in the Sauerland Karst and other caves of Europe.     

Considerations on the potential use of cliffs and caves by the extinct endemic late pleistocene hippopotami and elephants of Cyprus

Most of the fossil mammal sites on Cyprus, as well as on other Mediterranean islands, consist of large quantities of bones found in caves. Of 32 sites with Phanourios minutus and 21 with Elephas cypriotes on Cyprus, 19 were located in caves, two in rock-shelters, and 11 at open-air sites. Fifteen of them were littoral, four coastal, and 13 inland. The purpose of this paper is to examine possible reasons why Phanourios and Elephas remains accumulated mainly in littoral and coastal caves. Based on an analysis of the behavior exhibited by living hippopotami and elephants, we assume that the extinct large mammals of Cyprus entered these caves in search of fresh water and to protect themselves from the heat in the cool and moist cave environment. A further reason may have been that these mammals entered the caves seeking mineral licks to rectify possible mineral deficiencies, to bind secondary plant compounds such as tannins, or to counteract acidosis. By entering caves, or even passing along narrow paths through cliffs, they were at risk of becoming trapped in natural traps, such as caves with their openings facing upwards, sinkholes, and mire traps. There is no evidence that Phanourios and Elephas remains were accumulated by natural predators because on the island there were no predators large enough to carry such large mammals. The only exception are the remains in the Akrotiri Aetokremnos rock shelter on the Akrotiri peninsula, where there is evidence that the 218,459 Phanourios and 330 Elephas remains were accumulated by the first human settlers of Cyprus, about 10,000 years BP.     

Trichosporon Species Isolated from Guano Samples Obtained from Bat-Inhabited Caves in Japan

Yeasts from caves have rarely been examined. We examined yeasts collected from bat guano samples from 20 bat-inhabited limestone and volcanic caves located in 11 prefectures in Japan. Of ~700 yeast-like colonies, nine Trichosporon species were recovered from 15 caves. Two of these were known species, and the remaining seven are potentially novel species, based on molecular phylogenetic analyses. In addition to Trichosporon species, identifiable strains of eight ascomycetous yeasts and one basidiomycetous yeast were recovered at frequencies of 5 to 35%. Our findings suggest that Trichosporon spp. are the major yeast species in bat guano in Japan and that bat guano is a potentially rich source of previously undescribed yeast species.     

Is Radon Emission in Caves Causing Deletions in Satellite DNA Sequences of Cave-Dwelling Crickets?

The most stable isotope of radon, ²²²Rn, represents the major source of natural radioactivity in confined environments such as mines, caves and houses. In this study, we explored the possible radon-related effects on the genome of Dolichopoda cave crickets (Orthoptera, Rhaphidophoridae) sampled in caves with different concentrations of radon. We analyzed specimens from ten populations belonging to two genetically closely related species, D. geniculata and D. laetitiae, and explored the possible association between the radioactivity dose and the level of genetic polymorphism in a specific family of satellite DNA (pDo500 satDNA). Radon concentration in the analyzed caves ranged from 221 to 26000 Bq/m³. Specimens coming from caves with the highest radon concentration showed also the highest variability estimates in both species, and the increased sequence heterogeneity at pDo500 satDNA level can be explained as an effect of the mutation pressure induced by radon in cave. We discovered a specific category of nuclear DNA, the highly repetitive satellite DNA, where the effects of the exposure at high levels of radon-related ionizing radiation are detectable, suggesting that the satDNA sequences might be a valuable tool to disclose harmful effects also in other organisms exposed to high levels of radon concentration.     

Influence of geomorphology and surface features on the genetic structure of an important trogloxene,the secret cave cricket (<Emphasis Type="Italic">Ceuthophilus secretus</Emphasis>)

Cave ecosystems supporting a variety of endemics depend on the carbon, nitrogen, and nutrients brought into caves by trogloxenic species, such as the secret cave cricket (Ceuthophilus secretus). Surface movements of trogloxenes may comprise the strongest ecological connections among caves. Our objective was to better understand dispersal patterns in C. secretus in order to inform management of this species and the cave endemics that depend upon them. We used microsatellite loci to estimate gene flow and genetic diversity among 42 karst features supporting C. secretus on the Fort Hood Military Reserve, Texas, USA. This sampling was used to assess the influences of karst topography and other landscape features on genetic diversity and population structure. Cave populations did not exhibit evidence of recent bottlenecks and genetic diversity was similar among sites, with the exception of one sample from an isolated cave. Samples exhibited a strong pattern of isolation by distance, but karst topology was also influential, with genetic differentiation being much higher between samples from separate ridges than among those on the same ridge. It appears that co-location on a ridge was an important factor facilitating dispersal among karst features. There was little evidence that other surface features such as forest cover, roads or streams influenced gene flow and genetic differentiation. The low genetic connectivity among ridges suggests that isolated caves on ridges where cricket habitat is uncommon or degraded might not be easily recolonized after extinction events, with potentially negative consequences for associated cave communities.     

Fish Assemblages of Mediterranean Marine Caves

Fish assemblages associated with 14 marine caves and adjacent external rocky reefs were investigated at four Marine Protected Areas (MPAs) along the coasts of Italy. Within the caves sampling was carried out in different sub-habitats: walls, ceilings, bottoms and ends of caves. On the whole, 38 species were recorded inside the 14 caves investigated. Eighteen species were exclusively found inside the caves: they were mainly represented by speleophilic (i.e. species preferentially or exclusively inhabiting caves) gobids (e.g. Didogobius splechtnai) and nocturnal species (e.g. Conger conger). Forty-one species were censused outside, 20 of which were shared with cave habitats. Apogon imberbis was the most common fish found in all 14 caves investigated, followed by Thorogobius ephippiatus (recorded in 13 caves), and Diplodus vulgaris and Scorpaena notata (both censused in 12 caves). Distinct fish assemblages were found between external rocky reefs and the different cave sub-habitats. New data on the distribution of some speleophilic gobids were collected, showing the existence of a pool of species shared by marine caves on a large scale (i.e. hundreds of km). Considering the uniqueness of cave fishes (18 exclusive species and different assemblage structures), the inclusion of marine caves among the habitats routinely investigated for fish biodiversity monitoring could facilitate the achievement of more comprehensive inventories. Due to their contribution to local species diversity and the shelter they provide to species valuable for conservation, marine caves should be prioritized for their inclusion not only within future MPAs through the Mediterranean Sea, but also into larger management spatial planning.     

Evidence of cave use by savanna chimpanzees (<Emphasis Type="Italic">Pan troglodytes verus</Emphasis>) at Fongoli,Senegal: implications for thermoregulatory behavior

Much attention has been paid to how humans both adapt and acclimate to heat stress, primarily due to the relevance of these issues to hominid evolution in open Plio-Pleistocene environments. However, little is known about the responses of human’s closest living relative, the chimpanzee (Pan troglodytes), to similar environmental stressors. In southeastern Senegal, one of the hottest and driest habitats that chimpanzees (P. t. verus) live in today, apes rely on behavioral mechanisms of dealing with thermal stress. Chimpanzees’ use of caves was based primarily on indirect evidence (feeding traces, feces, and hairs) gathered from one cave from January to December 2004, but data from observational records collected from May 2001 through March 2006 supplement these data. The hypothesis that chimpanzees’ use of caves is a response to heat was tested by collecting data on temperatures within the largest cave and in different habitats used by chimpanzees, such as gallery forest and woodland. Results indicate that chimpanzees primarily use caves as shelters during the hottest times of year and that caves are consistently and significantly cooler than open habitats. Insight into the way that chimpanzees in Senegal cope with extreme temperatures may help us to better understand the behavior of early hominids in such an environment.     

Spatial Structure of the community of bats (Chiroptera: Vespertilionidae) hibernating in artificial caves of Samarskaya Luka

Specific features of the spatial distribution and localization of bats have been studied during their hibernation in artificial caves of Samarskaya Luka. The proportion of cave area occupied by bats varies from 70 to 93% in large caves (>60000 m²), decreasing to 50% in medium-sized caves (10000–60000 m²) and to less than 30% in small caves (<10000 m²). Approximately 9% of bats choose sites near cave openings, up to 25% prefer central parts, but most bats (about 66%) concentrate in the deepest parts of caves. Among wintering species, higher rates of occurrence and shelter occupancy are characteristic of Plecotus auritus, Myotis daubentonii, and M. mystacinus, whereas M. dasycneme and M. brandtii show the highest degree of aggregation. The optimal temperature range for the wintering of all bat species is 2–4°C. Myotis brandtii, Eptesicus nilssonii, and M. daubentonii prefer to hibernate in open spaces of cave ceilings; M. mystacinus, E. serotinus, and Pl. auritus usually occupy the middle and upper parts of walls; while M. dasycneme and M. nattereri occur mainly in hollows on ceilings.     

Les sites acheuléens des grottes la Terrasse et du Coupe-Gorge, à Montmaurin,Haute Garonne,France

The huge karstic network of Montmaurin is located at the western end of the chain of the Petites Pyrenées, and contained several caves escavated by Louis Méroc and his team to 1946 at 1961. Among the eight caves that have escaped the exploitation of quarrymen the richest in stone industry and fauna are the caves la Terrasse and le Coupe-Gorge which are Acheulean sites. The techno-typological and petro-archaeological study conducted during this research shows the specificities inherent to the Montmaurin caves. The lithological procession is composed of pebbles quartzite lydian quartz etc. that come from the tributaries of the Garonne and pre-Pyrenean flint. The acquisition territories of mineral resources are more or less vast, from a hundred meters to about 80 kilometers. The techno-typological characteristics of the Montmaurin cave's industries testify a technical and economic behavior oriented towards production and consumption activities in situ. Differential management of lithic resources is observed, which echoes both the technical requirements imposed by the debitage methods employed and the knapping skills.     

Hunting,Swimming, and Worshiping: Human Cultural Practices Illuminate the Blood Meal Sources of Cave Dwelling Chagas Vectors (Triatoma dimidiata) in Guatemala and Belize

Background

Triatoma dimidiata, currently the major Central American vector of Trypanosoma cruzi, the parasite that causes Chagas disease, inhabits caves throughout the region. This research investigates the possibility that cave dwelling T. dimidiata might transmit the parasite to humans and links the blood meal sources of cave vectors to cultural practices that differ among locations.

Methodology/Principal Findings

We determined the blood meal sources of twenty-four T. dimidiata collected from two locations in Guatemala and one in Belize where human interactions with the caves differ. Blood meal sources were determined by cloning and sequencing PCR products amplified from DNA extracted from the vector abdomen using primers specific for the vertebrate 12S mitochondrial gene. The blood meal sources were inferred by ≥99% identity with published sequences. We found 70% of cave-collected T. dimidiata positive for human DNA. The vectors had fed on 10 additional vertebrates with a variety of relationships to humans, including companion animal (dog), food animals (pig, sheep/goat), wild animals (duck, two bat, two opossum species) and commensal animals (mouse, rat). Vectors from all locations fed on humans and commensal animals. The blood meal sources differ among locations, as well as the likelihood of feeding on dog and food animals. Vectors from one location were tested for T. cruzi infection, and 30% (3/10) tested positive, including two positive for human blood meals.

Conclusions/Significance

Cave dwelling Chagas disease vectors feed on humans and commensal animals as well as dog, food animals and wild animals. Blood meal sources were related to human uses of the caves. We caution that just as T. dimidiata in caves may pose an epidemiological risk, there may be other situations where risk is thought to be minimal, but is not.     

Making a living while starving in the dark: metagenomic insights into the energy dynamics of a carbonate cave

Carbonate caves represent subterranean ecosystems that are largely devoid of phototrophic primary production. In semiarid and arid regions, allochthonous organic carbon inputs entering caves with vadose-zone drip water are minimal, creating highly oligotrophic conditions; however, past research indicates that carbonate speleothem surfaces in these caves support diverse, predominantly heterotrophic prokaryotic communities. The current study applied a metagenomic approach to elucidate the community structure and potential energy dynamics of microbial communities, colonizing speleothem surfaces in Kartchner Caverns, a carbonate cave in semiarid, southeastern Arizona, USA. Manual inspection of a speleothem metagenome revealed a community genetically adapted to low-nutrient conditions with indications that a nitrogen-based primary production strategy is probable, including contributions from both Archaea and Bacteria. Genes for all six known CO₂-fixation pathways were detected in the metagenome and RuBisCo genes representative of the Calvin–Benson–Bassham cycle were over-represented in Kartchner speleothem metagenomes relative to bulk soil, rhizosphere soil and deep-ocean communities. Intriguingly, quantitative PCR found Archaea to be significantly more abundant in the cave communities than in soils above the cave. MEtaGenome ANalyzer (MEGAN) analysis of speleothem metagenome sequence reads found Thaumarchaeota to be the third most abundant phylum in the community, and identified taxonomic associations to this phylum for indicator genes representative of multiple CO₂-fixation pathways. The results revealed that this oligotrophic subterranean environment supports a unique chemoautotrophic microbial community with potentially novel nutrient cycling strategies. These strategies may provide key insights into other ecosystems dominated by oligotrophy, including aphotic subsurface soils or aquifers and photic systems such as arid deserts.     

Habitat fragmentation and the prevalence of parasites (Diptera,Streblidae) on three Phyllostomid bat species

Ectoparasitism in bats seems to be influenced strongly by the type of roost preferred by the hosts, and group size; however, the effect of habitat loss and fragmentation on the prevalence of ectoparasites in bats has scarcely been studied. In northeastern Yucatan, Mexico, we estimated the prevalence of infestation by Streblidae flies in three phyllostomid bat species with different roost preferences (caves, trees, or both) in two types of landscape matrices (tropical semi‐deciduous forest and man‐made pastures) that differed in area of forest cover and the number of forest fragments. Habitat fragmentation and the presence of a contrasting matrix may limit the availability of roosts (trees) and the movement of bats across the landscape. Accordingly, we hypothesized higher prevalence of Streblidae infestation in the pasture matrix and in the group of bats that roost in trees. Bat abundance was higher in the pasture matrix; however, the prevalence of infestation was significantly higher in the continuous forest matrix and in bats that roosted in caves. The prevalence of some species of Streblidae was affected by habitat fragmentation in species that roost in caves, such as Desmodus rotundus, as well as those using foliage and caves, such as Artibeus jamaicensis. Our results provide evidence that some species of Streblidae may respond differently to habitat fragmentation than their hosts, generating changes to bat‐ectoparasite interactions in fragmented areas. Environmental variations involving roosts, not evaluated in this study, may influence our results, since these factors affect ectoparasite abundance and reproduction.     

The largest European lion Panthera leo spelaea (Goldfuss 1810) population from the Zoolithen Cave,Germany: specialised cave bear predators of Europe

Remains of 13 individuals with 3/1 male/female ratio of the extinct Upper Pleistocene lion Panthera leo spelaea (Goldfuss, 1810) from the Zoolithen Cave near Burggeilenreuth (Bavaria, Germany) include the holotype skull and all paratype material. The highest mortality rate for the Zoolithen Cave lions is in their reproductive adult ages. Bite marks on lion bones or skulls are results of hyena activities, or rare cannibalism of lions under stress situations. Lions were possibly also killed in battles with cave bears during predation on hibernating bears in winter times. This cave bear hunt specialisation in caves overlaps with the ecological behaviour of cave bear feeding by Ice Age-spotted hyenas. Both largest Ice Age predators, lions and hyenas, had to specialise on feeding herbivorous cave bears in boreal forest mountainous cave rich regions, where the mammoth steppe megafauna prey was absent. This cave bear hunt by felids, and scavenging by hyenas and other large carnivores such as leopards and wolves explains why cave bears hibernated deep in to the European caves, for protection reasons against predators. Within such lion–cave bear and even lion–hyena conflicts in the caves lions must have been killed sometimes, explaining mainly the skeleton occurrences in different European caves.     

Bubble-Induced Cave Collapse

Conventional wisdom among cave divers is that submerged caves in aquifers, such as in Florida or the Yucatan, are unstable due to their ever-growing size from limestone dissolution in water. Cave divers occasionally noted partial cave collapses occurring while they were in the cave, attributing this to their unintentional (and frowned upon) physical contact with the cave walls or the aforementioned “natural” instability of the cave. Here, we suggest that these cave collapses do not necessarily result from cave instability or contacts with walls, but rather from divers bubbles rising to the ceiling and reducing the buoyancy acting on isolated ceiling rocks. Using familiar theories for the strength of flat and arched (un-cracked) beams, we first show that the flat ceiling of a submerged limestone cave can have a horizontal expanse of 63 meters. This is much broader than that of most submerged Florida caves (~ 10 m). Similarly, we show that an arched cave roof can have a still larger expanse of 240 meters, again implying that Florida caves are structurally stable. Using familiar bubble dynamics, fluid dynamics of bubble-induced flows, and accustomed diving practices, we show that a group of 1-3 divers submerged below a loosely connected ceiling rock will quickly trigger it to fall causing a “collapse”. We then present a set of qualitative laboratory experiments illustrating such a collapse in a circular laboratory cave (i.e., a cave with a circular cross section), with concave and convex ceilings. In these experiments, a metal ball represented the rock (attached to the cave ceiling with a magnet), and the bubbles were produced using a syringe located at the cave floor.     

A new sigillid ostracod from submarine caves of the Ryukyu Islands, Japan

A new troglobitic sigillid genus, Kasella , is found in the submarine caves of the Ryukyu Islands. Sigillids are primitive podocopid ostracods having ancient characters such as unequal valves and many small adductor muscle scars. Kasella is possibly derived from the sigillid Cardobairdia , a deep-sea muddy bottom inhabitant, or its relatives. Submarine caves are characterized as both 'safe places', where biological factors such as competition and predation are reduced, and as 'crypts', representing dark and oligotrophic environments. It is likely that Kasella has successfully colonized hard substrates in caves, particularly exploiting the crevices on cave walls and ceilings. Kasella may have adapted to this cryptic habitat in response to strong cytheroidean competition and predation by, for example, gastropods that do not survive well in dark and oligotrophic submarine caves. In adapting to an oligotrophic cave environment, Kasella has undergone significant divergence in carapace morphology, possibly accompanying functional and behavioural changes.