112,609 research outputs found
Female mating preferences in blind cave tetras Astyanax fasciatus (Characidae, Teleostei).
No full textThe Mexican tetra Astyanax fasciatus has evolved a variety of more or less color- and eyeless cave populations. Here we examined the evolution of the female preference for large male body size within different populations of this species, either surface- or cave-dwelling. Given the choice between visual cues from a large and a small male, females from the surface form as well as females from an eyed cave form showed a strong preference for large males. When only non-visual cues were presented in darkness, the surface females did not prefer either males. Among the six cave populations studied, females of the eyed cave form and females of one of the five eyeless cave populations showed a preference for large males. Apparently, not all cave populations of Astyanax have evolved non-visual mating preferences. We discuss the role of selection by benefits of non-visual mate choice for the evolution of non-visual mating preferences
Niugini Caver: Newsletter of the Papua New Guinea Cave Exploration Group
No full textToktok Bilong Edita -- Maps of P.N.G Caves -- Australian Spaleo Abstracts -- The New Contributors -- Corrections Niugini Cover Volume 1, Number 1 -- Next Issue -- Arafura Cave, Snake River Are, Morobe District / H. Gallasch -- A Large Cave and Doline Near Tuke Village, Pom ?o Sub-district, New Britain / C.J. Borough -- The 1972-3 U.Q.S.S New Britain Expedition / R. Michael Bourke -- Trip to Gaulim Caves, Gazelle Peninsula / Iyo Mesibere -- Obituary - DerekClark / R. Michael Bourke -- The Caving Scene -- Gagogangama Cave, Porol Escarpment, Chimbu District / V Watson -- Obondo'Yonaminge Cave, Chimbu District / K. A. Wilde -- Sigewagi Cave, Chimbu Gorge, Chimbu District / K. A. Wilde -- Mebile Cave, Chimbu District / Bill Sanders
The ecology and conservation of cave roosting bats in the Yorkshire Dales
No full textThe caves of the Yorkshire Dales National Park are potentially an important assemblage of underground bat sites, but prior to this study nothing was known about the ecology of cave use. Between 2002 and 2005,53 cave entrances were logged for swarming activity using automated echolocation call loggers. A subset was chosen for continuous monitoring outside the hibernation period and another for winter logging. Logging was followed up by trapping at caves with significant autumn bat activity. All bats caught were ringed, identified to species and sexed. Biopsies (3 mm diameter) were taken from each wing for genetic analysis.
A large proportion of the caves surveyed were used by bats, but activity was concentrated in a small number of hotspots. Peak activity occurred during August and September, but significant activity was recorded in all months between March and October. All five swarming species were caught at most sites: Myotis brandtii, M. daubentonii, M. mystacinus, M. nattereri and Plecotus auritus. M. nattereri was the most abundant species late in September, but earlier other species made up a significant proportion of those caught. The sex ratio of swarming bats was heavily skewed towards males.
Swarming activity was positively correlated with the degree of cave chamber development, cave length and shelter at the entrance, and negatively correlated with the amount of water the cave carried. Entrance size, altitude and the degree of connectivity between cave and summer habitat were not correlated with activity. In a multiple regression model, chamber development and hydrology were the best predictors of activity. Entrance orientation and shelter contributed towards the model but were less important. The regression model could explain 55% of the variance in bat activity.
Genetic diversity of Myotis nattereri, based on an analysis of six microsatellite loci, was high in swarming populations suggesting high gene flow and large effective populations. Most of the genetic variation was explained by variation among individuals within populations, but some was due to differences between swarming areas and by differences between populations within swarming areas. Isolation by distance was found between sites in six swarming areas between Cumbria and Sussex, but not between sites in the Yorkshire Dales. The differentiation observed was more logically explained on the basis of local geography and probable catchment areas.
Preliminary experiments suggest that Time Domain Signal Coding has potential as a sound analysis system for real time bat call identification
Niugini Caver: Newsletter of the Papua New Guinea Cave Exploration Group
No full textIntroducing "Niugini Caver" ...... and This Issue -- Bibima Cave, Porol Escarpment, Chimbu District / Kevan Wilde and Van Watson -- The Hinderburg Wall / Malcolm Robb -- The Contributors -- Loniu Cave, Los Negros Island, Manus District / H. Gallasch -- Caves of New Britain. A Preliminary Report / R. Michael Bourk
The Late Natufian at Raqefet Cave: The 2006 Excavation Season
No full textA long season of excavation took place at Raqefet cave during the summer of 2006. In the
first chamber we exposed an area rich with Natufian human burials (Locus 1), a large bedrock
basin with a burial and two boulder mortars (Locus 2), an in situ Natufian layer (Locus 3),
and two areas with rich cemented sediments (tufa) covering the cave floor (Loci 4, 5). The
latter indicate that at the time of occupation the Natufian layers covered the entire floor of
the first chamber. During the ensuing millennia, these were washed away and/or removed
by later visitors to the cave. We found in the cave and the terrace almost 80 human-made
bedrock holes (most of which are commonly but somewhat erroneously termed mortars
and cupmarks). Several contained in situ Natufian remains, and at the top of one a human
skeleton was unearthed. The variety of the HBHs, in terms of shape and dimensions indicates
that they were used in many ways, some of which could not have been for food or mineral
processing. The paper provides results of on-going studies regarding the burials, the HBHs,
the flint assemblage, the faunal remains, the ground stone industry, the bone tools and the
beads. It also presents aspects of geoarchaeology and ground penetrating radar analyses.
Some of the detailed plans and sections were prepared by the use of photogrammetry
The impact of declining groundwater levels on Stygofauna communities in the Leeuwin naturaliste ridge cave systems, Western Australia
No full textGroundwater Dependent Ecosystems (GDE 19s) are intrinsically connected to rainfall and groundwater for survival. Many ecosystems are becoming increasingly threatened due to the accelerating pressures of climate change and disturbances to connecting ecosystems. This thesis examined the structural changes of the Threatened Ecological Communities (TEC 19s) living within the GDE of Leeuwin Naturaliste Ridge (LNR) and Yanchep, Western Australia, as well as water quality of each of these cave systems. Multidimensional scaling, Simper analysis and BIOENV techniques were used to characterize and compare water quality, quantity and community structure. It was found that each cave contained a distinct faunal community contribution and that three caves of LNR were distinct in their ionic compositions. Factors that may have contributed to the biological and physical differentiation of these caves include the extensive evolutionary and hydrogeological development of each cave. Threats to cave systems were also identified, including climate change induced rainfall decline and anthropogenic stressors. Finally, management strategies for future conservation were suggested. Overall, reduced groundwater levels induced by rainfall decline seemed to have an important effect on cave TEC
Bacterial metabolism of methylated amines and identification of novel methylotrophs in Movile Cave
No full textMovile Cave, Romania, is an unusual underground ecosystem that has been sealed off from the outside world for several million years and is sustained by non-phototrophic carbon fixation. Methane and sulfur-oxidising bacteria are the main primary producers, supporting a complex food web that includes bacteria, fungi and cave-adapted invertebrates. A range of methylotrophic bacteria in Movile Cave grow on one-carbon compounds including methylated amines, which are produced via decomposition of organic-rich microbial mats. The role of methylated amines as a carbon and nitrogen source for bacteria in Movile Cave was investigated using a combination of cultivation studies and DNA stable isotope probing (DNA-SIP) using 13C-monomethylamine (MMA). Two newly developed primer sets targeting the gene for gamma-glutamylmethylamide synthetase (gmaS), the first enzyme of the recently-discovered indirect MMA-oxidation pathway, were applied in functional gene probing. SIP experiments revealed that the obligate methylotroph Methylotenera mobilis is one of the dominant MMA utilisers in the cave. DNA-SIP experiments also showed that a new facultative methylotroph isolated in this study, Catellibacterium sp. LW-1 is probably one of the most active MMA utilisers in Movile Cave. Methylated amines were also used as a nitrogen source by a wide range of non-methylotrophic bacteria in Movile Cave. PCR-based screening of bacterial isolates suggested that the indirect MMA-oxidation pathway involving GMA and N-methylglutamate is widespread among both methylotrophic and non-methylotrophic MMA utilisers from the cave
New AMS (14)C dates from the early Upper Paleolithic sequence of Raqefet Cave, Mount Carmel, Israel
No full textRaqefet Cave (35°04'21"N, 32°39'17"W) is situated in the southeastern side of Mount Carmel in Israel (Figure 1) on the left bank of wadi Raqefet (230 m asl), ~50 m above the wadi bed. It is 50 m long with an area of ~500 m2 (Figure 2). Eric Higgs of Cambridge University and Tamar Noy of the Israel Museum conducted excavations at the site between 1970 and 1972 (Higgs et al. 1975). New excavations at the cave began in 2004 (Lengyel et al. 2005)
Thermal stability of stercorite H(NH4)Na(PO4)·4H2O – a cave mineral from Petrogale Cave, Madura, Eucla, Western Australia
No full textThermogravimetric analysis has been used to determine the thermal stability of the mineral stercorite H(NH4)Na(PO4)·4H2O. The mineral stercorite originated from the Petrogale Cave, Madura, Eucla, Western Australia. This cave is one of many caves in the Nullarbor Plain in the South of Western Australia. The mineral is formed by the reaction of bat guano chemicals on calcite substrates. Upon thermal treatment the mineral shows a strong decomposition at 191°C with loss of water and ammonia. Other mass loss steps are observed at 158, 317 and 477°C. Ion current curves indicate a gain of CO2 at higher temperature and are attributed to the thermal decomposition of calcite impurity
Polystichum tiandengense (subg. Haplopolystichum; Dryopieridaceae), a New Cave Fern from Guangxi, China
No full textA new fern species, Polystichum tiandengense H. He & Li Bing Zhang (Dryopteridaceae), is described and illustrated from a limestone cave in the Guangxi Zhuangzu Autonomous Region, South China. Polystichum tiandengense is most similar to P. cavernicola. Li Bing Zhang & H. lie in having oblong to square pinnae with undulate margins, but the new species is distinguished by its pinnae mostly adjacent to each other or imbricating, and mostly sterile (vs. distant from each other and mostly fertile in P. cavernicola). Polystichum tiandengense is considered to be Critically Endangered (CR), based on RICN Red List criteria
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