• Quantifying individual feeding variability: implications for mollusc feeding experiments

      Hanley, M. E.; Bulling, Mark T.; Fenner, M. (2013-05-24)
      1. In order to quantify the level of variability in seedling consumption displayed by individual molluscs, we placed one snail ( Helix aspersa ) in each of 51 trays containing (7-day-old) Taraxacum officinale seedlings for 7 days. 2. Initially, individual snails displayed considerable variability in their consumption of seedlings; however, this variability declined with time. The consumption of seedlings was not related to individual snail mass. 3. A second grazing experiment, using five different snail densities in similar experi- mental conditions to the first, showed that increasing snail number reduced variability within treatment groups. 4. A computer simulation, based on data from the first experiment correctly predicted the basic form of the decline in feeding variability with increasing snail density found in the second. Post hoc changes to the model, based on empirical analysis of the second experiment to account for mutual interference, reduced discrepancies between empirical and model results. 5. This study highlights the consequences that individual feeding behaviour has on feeding trials with molluscs, and provides a simple method by which this variability can be quantified and accommodated within experimental design.
    • Quantitative mapping of alluvial fan evolution using ground-based reflectance spectroscopy

      Ferrier, Graham; Pope, Richard J. J.; University of Hull; University of Derby (2012)
      The ability of field-based reflectance spectroscopy to resolve the relative proportions of Fe-oxides and clays in soils was used to map the composition, relative age and distribution of segments within late Quaternary fan systems in Sfakia, southwest Crete. The spectrometric results demonstrate that luvisols that have formed on the surfaces of fan segments are characterized by distinctive Fe-oxides (types) and clay minerals (species). Furthermore, Fe-oxide and clay concentrations display a clear and consistent trend whereby for each study fan luvisols formed on increasingly proximal fan segments are characterized by a progressive build-up of spectrally distinct secondary iron oxides and clay minerals, which suggests that proximal segments formed first. The relative ages and hence order of formation of segments suggested by the spectral data are strongly supported by an optically stimulated luminescence (OSL)-based geochronology which provides a tentative maximum age of 144 ka for the oldest (stage 1) surface and 11.2 ka for the youngest (stage 2C) surface. Moreover, the chronometric data indicate that time intervals of the order 20 to 25,000 years are necessary to generate sufficient differences in pedogenic Fe-oxides and clay concentrations to enable differentiation of fan segments by field spectroscopy. ⺠Field-based reflectance spectroscopy was used to map alluvial fan segments. ⺠Strong relationships between spectral profiles and soil composition were identified. ⺠Fan segments were differentiated using time interval between depositional events. ⺠Age differences of 25,000 years are required to differentiate fan segments.
    • Rain-fed granite rock basins accumulate a high diversity of dormant microbial eukaryotes

      Velasco-González, Ismael; Sanchez-Jimenez, Abel; Singer, David; Murciano, Antonio; Díez-Hermano, Sergio; Lara, Enrique; Martín-Cereceda, Mercedes; Departamento de Genética, Fisiología y Microbiología. Facultad de Ciencias Biológicas, Universidad Complutense de Madrid (UCM), C/ José Antonio Novais 12, 28040, Madrid, Spain; Departamento de Biodiversidad, Ecología y Evolución. Facultad de Ciencias Biológicas, UCM, Madrid, Spain; University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Neuchâtel, Switzerland; et al. (Springer Science and Business Media LLC, 2019-12-03)
      Rain fed granite rock basins are ancient geological landforms of worldwide distribution and structural simplicity. They support habitats that can switch quickly from terrestrial to aquatic along the year. Diversity of animals and plants, and the connexion between communities in different basins have been widely explored in these habitats, but hardly any research has been carried out on microorganisms. The aim of this study is to provide the first insights on the diversity of eukaryotic microbial communities from these environments. Due to the ephemeral nature of these aquatic environments, we predict that the granitic basins should host a high proportion of dormant microeukaryotes. Based on an environmental DNA diversity survey, we reveal diverse communities with representatives of all major eukaryotic taxonomic supergroups, mainly composed of a diverse pool of low abundance OTUs. Basin communities were very distinctive, with alpha and beta diversity patterns non-related to basin size or spatial distance respectively. Dissimilarity between basins was mainly characterised by turnover of OTUs. The strong microbial eukaryotic heterogeneity observed among the basins may be explained by a complex combination of deterministic factors (diverging environment in the basins), spatial constraints, and randomness including founder effects. Most interestingly, communities contain organisms that cannot coexist at the same time because of incompatible metabolic requirements, thus suggesting the existence of a pool of dormant organisms whose activity varies along with the changing environment. These organisms accumulate in the pools, which turns granitic rock into high biodiversity microbial islands whose conservation and study deserve further attention.
    • Rapid assembly of high-Mg andesites and dacites by magma mixing at a continental arc stratovolcano

      Conway, Chris; Chamberlain, Katy J.; Harigane, Yumiko; Morgan, Daniel; Wilson, Colin; Research Institute of Earthquake and Volcano Geology, Japan; National Museum of Nature and Science, Japan; University of Derby; University of Leeds; Victoria University of Wellington (The Geological Society of America, 2020-06-25)
      Studies of pre-eruptive processes at active volcanoes require precise petrochronological constraints if they are to contribute to hazard assessment during future eruption events. We present petrological and geochemical data, and orthopyroxene diffusion timescales for samples from late Pleistocene high-Mg andesite dacite lavas (Mg#53–69) at Ruapehu volcano, New Zealand, as a case study of rapid magma genesis and eruption at a continental arc stratovolcano. Assembly of Ruapehu high-Mg magmas involved the mixing of primitive magmas plus entrained mantle equilibrated olivines with mid-crustal felsic mush bodies, yielding hybridized magmas with ubiquitous pyroxene reverse-zoning patterns. Orthopyroxene Fe-Mg interdiffusion timescales linked to quantitative crystal orientation data show that most lavas erupted <10 days after resumption of crystal growth following magma mixing events. The eruption of lavas within days of mixing events implies that pre-eruptive warnings may be correspondingly short.
    • Reconstruction of former glacier surface topography from archive oblique aerial images

      Midgley, Nicholas G.; Tonkin, Toby N.; Nottingham Trent University; University of Derby (Elsevier, 2017-01-06)
      Archive oblique aerial imagery offers the potential to reconstruct the former geometry of valley glaciers and other landscape surfaces. Whilst the use of Structure-from-Motion (SfM) photogrammetry with multiview stereopsis (MVS) to process small-format imagery is now well established in the geosciences, the potential of the technique for extracting topographic data from archive oblique aerial imagery is unclear. Here, SfM-MVS is used to reconstruct the former topography of two high-Arctic glaciers (Midtre and Austre Lovénbreen, Svalbard, Norway) using three archive oblique aerial images obtained by the Norwegian Polar Institute in 1936. The 1936 point cloud was produced using seven LiDAR-derived ground control points located on stable surfaces in proximity to the former piedmont glacier termini. To assess accuracy, the 1936 data set was compared to a LiDAR data set using the M3C2 algorithm to calculate cloud-to-cloud differences. For stable areas (such as nonglacial surfaces), vertical differences were detected between the two point clouds (RMS M3C2 vertical difference of 8.5 m), with the outwash zones adjacent to the assessed glacier termini showing less extensive vertical discrepancies (94% of M3C2 vertical differences between ± 5 m). This research highlights that historical glacier surface topography can be extracted from archive oblique aerial imagery, but accuracy is limited by issues including the lack of camera calibration, the quality and resolution of the archive imagery, and by the identification of suitable ground control. To demonstrate the value of historical glacier surfaces produced using oblique archive imagery, the reconstructed glacier surface topography is used to investigate evidence of a potential former surge front at the high-Arctic valley glacier, Austre Lovénbreen — a glacier identified to have potentially exhibited surge-type behaviour during the Neoglacial. A surface bulge of ~ 15–20 m is resolved on the 1936 model; however, when compared with the now deglaciated former subglacial topography, a surge origin for the surface feature becomes unclear. The processed 1936 oblique imagery was also used to produce orthorectified nadir aerial imagery, from which structural mapping was undertaken: this adds to the existing 1948–1995 structural map series for these glaciers. This research demonstrates the potential of SfM-MVS for reconstructing historical glacier surfaces, which is important for aiding our understanding of former glacier dynamics and enabling the rapid assessment of glacier change over time.
    • Rediscovery of the critically endangered ‘scarce yellow sally stonefly’ Isogenus nubecula in United Kingdom after a 22 year period of absence.

      Davy-Bowker, John; Hammett, Michael J.; Mauvisseau, Quentin; Sweet, Michael J.; Freshwater Biological Association; Natural History Museum; Tyn Y Berth Mountain Centre; University of Derby (Magnolia Press, 2018-03-14)
      The critically endangered ‘scarce yellow sally stonefly’ Isogenus nubecula (Newman, 1833) (Plecoptera: Perlodidae) was rediscovered in the United Kingdom (UK) in 2017. This rediscovery comes after a 22-year period of absence despite numerous surveys since its last record in 1995. This species is one of the rarest stoneflies in the UK and Europe and its rediscovery is of international significance, being the westernmost point in Europe where the species is found, with the next nearest populations occurring in Austria and western Hungary, Slovakia, and central Sweden. The species is classed as pRDB2 (vulnerable), however is not listed in the British Red Data Book despite only being present (as far as records detail) in one river, the River Dee in North Wales, UK. Only fourteen individuals were caught and the need for conservation of this rare stonefly is therefore of paramount importance. We have made recommendations for the need to increase survey effort using environmental DNA (eDNA) techniques in order to fully understand the species range in this river and those in the surrounding area. The DNA sequence of I. nubecula has been uploaded on GenBank for further genetic studies. Captive rearing could also be explored with possible reintroductions to sites within its former UK range. 
    • Relationship between moonlight and nightly activity patterns of the ocelot (Leopardus pardalis) and some of its prey species in Formosa, Northern Argentina

      Huck, Maren; Juárez, Cecilia P.; Fernández-Duque, Eduardo; University of Derby (Elsevier, 2016-10-31)
      The moon can profoundly influence the activity patterns of animals. If predators are more successful under bright moonlight, prey species are likely to respond by shifting their own activity patterns (predator-avoidance hypothesis). However, the assumption that prey will necessarily avoid full-moon nights does not take into account that moonlight also allows prey to more easily detect predators, and to forage more efficiently. Thus, nightly activity patterns could depend on night vision capabilities (visual-acuity hypothesis). To consider the possible influences of moonlight and to distinguish between these hypotheses, we used camera-trapping records of a predator, the ocelot (Leopardus pardalis), and several of its night-active prey to compare activity patterns under different moonlight conditions. The ocelots' activity patterns were not strongly related to moonlight, but showed a slight tendency for higher activity during brighter nights. Tapeti rabbits (Sylvilagus brasiliensis) and brocket deer (Mazama americana) showed a clear preference for brighter nights. White-eared opossums (Didelphis albiventris) also showed a trend to be less active in new moon light. In contrast, smaller grey four-eyed opossums (Philander opossum) and the poor eye-sight nine-banded armadillo (Dasypus novemcinctus) showed similar activity patterns across all moon phases. Since activity patterns of most prey species were not shifted away from the activity of the ocelot, the differences between species are probably linked to their night vision capabilities, and emphasise the need for more information on the visual system of these taxa. Their activity patterns seem to be less strongly linked to avoidance of predation than previously thought, suggesting that foraging and predator detection benefits may play a more important role than usually acknowledged.
    • Reliable eDNA detection and quantification of the European weather loach (Misgurnus fossilis)

      Brys, Rein; Halfmaerten, David; Neyrinck, Sabrina; Mauvisseau, Quentin; Auwerx, Johan; Sweet, Michael; Mergeay, Joachim; Research Institute for Nature and Forest, Geraardsbergen, Belgium; University of Derby; SureScreen Scientifics Ltd (Wiley, 2020-03-10)
      The European weather loach (Misgurnus fossilis) is a cryptic and poorly known fish species of high conservation concern. The species is experiencing dramatic population collapses across its native range to the point of regional extinction. Although environmental DNA (eDNA)‐based approaches offer clear advantages over conventional field methods for monitoring rare and endangered species, accurate detection and quantification remain difficult and quality assessment is often poorly incorporated. In this study, we developed and validated a novel digital droplet PCR (ddPCR) eDNA‐based method for reliable detection and quantification, which allows accurate monitoring of M. fossilis across a number of habitat types. A dilution experiment under laboratory conditions allowed the definition of the limit of detection (LOD) and the limit of quantification (LOQ), which were set at concentrations of 0.07 and 0.14 copies μl–1, respectively. A series of aquarium experiments revealed a significant and positive relationship between the number of individuals and the eDNA concentration measured. During a 3 year survey (2017–2019), we assessed 96 locations for the presence of M. fossilis in Flanders (Belgium). eDNA analyses on these samples highlighted 45% positive detections of the species. On the basis of the eDNA concentration per litre of water, only 12 sites appeared to harbour relatively dense populations. The other 31 sites gave a relatively weak positive signal that was typically situated below the LOQ. Combining sample‐specific estimates of effective DNA quantity (Qe) and conventional field sampling, we concluded that each of these weak positive sites still likely harboured the species and therefore they do not represent false positives. Further, only seven of the classified negative samples warrant additional sampling as our analyses identified a substantial risk of false‐negative detections (i.e., type II errors) at these locations. Finally, we illustrated that ddPCR outcompetes conventional qPCR analyses, especially when target DNA concentrations are critically low, which could be attributed to a reduced sensitivity of ddPCR to inhibition effects, higher sample concentrations being accommodated and higher sensitivity obtained.
    • Repeated observations of cetaceans and carcharhiniformes associations in the Red Sea

      Röthig, Till; Spaet, Julia L. Y.; Kattan, Alexander; Schulz, Isabelle K.; Roberts, May; Roik, Anna; Voolstra, Christian R.; King Abdullah University of Science and Technology (KAUST) (Springer, 2015-06-27)
    • The “resort effect”: Can tourist islands act as refuges for coral reef species?

      Moritz, Charlotte; Ducarme, Frédéric; Sweet, Michael J.; Fox, Michael D.; Zgliczynski, Brian; Ibrahim, Nizam; Basheer, Ahmed; Furby, Kathryn A.; Caldwell, Zachary R.; Pisapia, Chiara; et al. (Wiley, 2017-09-13)
      There is global consensus that marine protected areas offer a plethora of benefits to the biodiversity within and around them. Nevertheless, many organisms threatened by human impacts also find shelter in unexpected or informally protected places. For coral reef organisms, refuges can be tourist resorts implementing local environment-friendly bottom-up management strategies. We used the coral reef ecosystem as a model to test whether such practices have positive effects on the biodiversity associated with de facto protected areas.
    • Restricted ranging behaviour in a high-density population of urban badgers

      Davison, John; Huck, Maren; Delahay, R. J.; Roper, Timothy J.; University of Sussex (2008)
      Damage caused by badger setts is an important source of human–carnivore conflict in urban areas of the UK, yet little is known about the spatial distribution of urban badger setts or their pattern of occupation. We compared the density, spatial distribution and size of setts in four urban and two rural study areas in the UK and assessed the applicability to urban systems of distinguishing between ‘main’ and ‘outlier’ setts. In addition, we used radio-telemetry to investigate diurnal patterns of sett use in one urban area (Brighton). It was possible to distinguish between main and outlier setts in urban environments, and local sett densities were comparable in urban and rural areas. However, urban badgers used substantially fewer setts than did a nearby rural population, and they spent a smaller proportion of days in outlier setts. Social groups with larger ranges had more setts available to them and, within groups, individuals with larger ranges used more setts. Outliers appeared to serve multiple functions, including allowing efficient and safe travel to important parts of the home range. We conclude that sett densities can be high in urban habitats, suggesting significant potential for settrelated problems to arise. The fact that urban main setts can be distinguished from outliers enables management actions to be tailored accordingly. In particular, because main setts seem to represent a particularly valuable resource to urban badgers, alternatives to the closure of problem main setts need to be considered.
    • A review of ghost gear entanglement amongst marine mammals, reptiles and elasmobranchs

      Stelfox, Martin; Hudgins, Jillian; Sweet, Michael J.; University of Derby (2016-06)
      This review focuses on the effect that ghost gear entanglement has on marine megafauna, namely mammals, rep-tiles and elasmobranchs. A total of 76 publications and other sources of grey literature were assessed, and these highlighted that over 5400 individuals from 40 different species were recorded as entangled in, or associated with, ghost gear. Interestingly, there appeared to be a deficit of research in the Indian, Southern, and Arctic oceans; and so, we recommend that future studies focus efforts on these areas. Furthermore, studies assessing the effects of ghost gear on elasmobranchs, manatees, and dugongs should also be prioritised, as these groups were underrepresented in the current literature.The development of regional databases, capable of recording entanglement incidences following a minimum global set of criteria, would be a logical next step in order to analyse the effect that ghost gear has on megafauna populations worldwide.
    • A review of Pangaea dispersal and large igneous provinces – In search of a causative mechanism

      Peace, A.L.; Phethean, Jordan; Franke, D.; Foulger, G.R.; Schiffer, C.; Welford, J.K.; McHone, G.; Rocchi, S.; Schnabel, M.; Doré, A.G.; et al. (Elsevier, 2019-07-22)
      The breakup of Pangaea was accompanied by extensive, episodic, magmatic activity. Several Large Igneous Provinces (LIPs) formed, such as the Central Atlantic Magmatic Province (CAMP) and the North Atlantic Igneous Province (NAIP). Here, we review the chronology of Pangaea breakup and related large-scale magmatism. We review the Triassic formation of the Central Atlantic Ocean, the breakup between East and West Gondwana in the Middle Jurassic, the Early Cretaceous opening of the South Atlantic, the Cretaceous separation of India from Antarctica, and finally the formation of the North Atlantic in the Mesozoic-Cenozoic. We demonstrate that throughout the dispersal of Pangaea, major volcanism typically occurs distal from the locus of rift initiation and initial oceanic crust accretion. There is no location where extension propagates away from a newly formed LIP. Instead, LIPs are coincident with major lithosphere-scale shear movements, aborted rifts and splinters of continental crust rifted far out into the oceanic domain. These observations suggest that a fundamental reappraisal of the causes and consequences of breakup-related LIPs is in order.
    • The role of floridoside in osmoadaptation of coral-associated algal endosymbionts to high-salinity conditions.

      Ochsenkühn, Michael A.; Röthig, Till; D’Angelo, Cecilia; Wiedenmann, Jörg; Voolstra, Christian R.; King Abdullah University of Science and Technology (KAUST); University of Southampton; New York University Abu Dhabi (American Association for the Advancement of Science, 2017-08-16)
      The endosymbiosis between Symbiodinium dinoflagellates and stony corals provides the foundation of coral reef ecosystems. The survival of these ecosystems is under threat at a global scale, and better knowledge is needed to conceive strategies for mitigating future reef loss. Environmental disturbance imposing temperature, salinity, and nutrient stress can lead to the loss of the Symbiodinium partner, causing so-called coral bleaching. Some of the most thermotolerant coral-Symbiodinium associations occur in the Persian/Arabian Gulf and the Red Sea, which also represent the most saline coral habitats. We studied whether Symbiodinium alter their metabolite content in response to high-salinity environments. We found that Symbiodinium cells exposed to high salinity produced high levels of the osmolyte 2-O-glycerol-α-d-galactopyranoside (floridoside), both in vitro and in their coral host animals, thereby increasing their capacity and, putatively, the capacity of the holobiont to cope with the effects of osmotic stress in extreme environments. Given that floridoside has been previously shown to also act as an antioxidant, this osmolyte may serve a dual function: first, to serve as a compatible organic osmolyte accumulated by Symbiodinium in response to elevated salinities and, second, to counter reactive oxygen species produced as a consequence of potential salinity and heat stress.
    • Role of functionally dominant species in varying environmental regimes: evidence for the performance-enhancing effect of biodiversity

      Langenheder, Silke; Bulling, Mark T.; Prosser, James I.; Solan, Martin (2013-05-24)
      Background Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. Results Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. Conclusions Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.
    • The role of viruses in coral health and disease

      Sweet, Michael J.; Bythell, John C.; University of Derby; Newcastle University (Elsevier, 2016-12-18)
      Metagenomic and electron microscopy studies confirm that the coral microbiome contains a rich diversity and abundance of viruses. While there have been no definitive tests of disease causation by viruses in corals, viruses have been implicated as coral pathogens in a number of studies. Growing evidence also indicates that latent viral infections can compromise the algal symbionts under environmental stress and may be involved in the coral bleaching response. Conversely, bacteriophages and archaeal phage viruses are abundant in the microbiome of healthy corals and are likely to be involved in complex ecological networks, genetic material transfer and selective co-evolution within the surface mucus layers and tissues. The relative importance of viral control of bacterial and archaeal populations is unknown, but they are almost certain to be exerting some level of control on the composition and maintenance of the coral microbiome. While rapid leaps in the capability to detect viruses have been made due to advances in metagenomics and bioinformatics, these approaches need now to be integrated with in vitro culture and challenge experiments to assess the functional roles of viruses in health and disease, and it is imperative that interactions with other members of the coral microbiome are taken into account when assessing disease causation.
    • Scent-marking investment and motor patterns are affected by the age and sex of wild brown bears

      Clapham, Melanie; Nevin, Owen T.; Rosell, Frank; Ramsey, Andrew; University of Derby (Elsevier, 2014-07-01)
      Members of the Carnivora employ a wide range of postures and patterns to mark their scent onto objects and thereby communicate with conspecifics. Despite much anecdotal evidence on the marking behaviour of ursids, empirical evidence of scent-marking motor patterns displayed by wild populations is lacking. Analysing the time that different age and sex classes spend at scent-marking trees and the behaviours involved at different times of year could provide further insight into the function of marking. We used camera traps stationed at scent-marking trees to investigate scent-marking behaviour by wild brown bears, Ursus arctos. Through image-based data, we found evidence to support the hypothesis that time investment and scent-marking motor patterns are dictated by the age and sex of the bear. Adult males spent more time scent marking and displayed a more complex behavioural sequence of marking than adult females and juveniles. Adult male behaviour at marking trees was consistent throughout the year, indicating a continued benefit of chemical signalling outside of the breeding season. Juvenile bear behaviour at marking trees changed with age. Young dependent cubs were more likely to imitate their mother's behaviour, whereas older dependent cubs were more likely to engage in marking behaviour independently. The marking motor patterns of independent subadults were more simplistic than those of younger dependent cubs, suggesting a change in behaviour with independence. We suggest that these findings further support the hypothesis that scent-marking behaviour by brown bears functions in intrasexual competition between adult males. Cub behaviour at marking trees suggests an influence of social learning.
    • Seasonality, DNA degradation and spatial heterogeneity as drivers of eDNA detection dynamics

      Troth, Christopher R.; Sweet, Michael J.; Nightingale, Jen; Burian, Alfred; University of Derby; SureScreen Scientifics Ltd, Morley; Bristol Zoological Society, Clifton, Bristol; University of Bristol; Lurio University, Nampula, Mozambique (Elsevier, 2021-01-06)
      In recent years, eDNA-based assessments have evolved as valuable tools for research and conservation. Most eDNA-based applications rely on comparisons across time or space. However, temporal, and spatial dynamics of eDNA concentrations are shaped by various drivers that can affect the reliability of such comparative approaches. Here, we assessed (i) seasonal variability, (ii) degradation rates and (iii) micro-habitat heterogeneity of eDNA concentrations as key factors likely to inflict uncertainty in across site and time comparisons. In a controlled mesocosm experiment, using the white-clawed crayfish as a model organism, we found detection probabilities of technical replicates to vary substantially and range from as little as 20 to upwards of 80% between seasons. Further, degradation rates of crayfish eDNA were low and target eDNA was still detectable 14–21 days after the removal of crayfish. Finally, we recorded substantial small-scale in-situ heterogeneity and large variability among sampling sites in a single pond of merely 1000m2 in size. Consequently, all three tested drivers of spatial and temporal variation have the potential to severely impact the reliability of eDNA-based site comparisons and need to be accounted for in sampling design and data analysis of field-based applications.
    • Seasonally resolved isotopic temperature data as a tool for identifying the cause of marine climate change in the Pliocene

      Johnson, Andrew L. A.; Valentine, Annemarie; Leng, Melanie J.; Sloane, Hilary J.; Schoene, Bernd; Surge, Donna; University of Derby; University of Loughborough; British Geological Survey; University of Mainz; et al. (2017-07-07)
      Alteration in the pattern and vigour of ocean currents has often been invoked as the principal driver of changes in regional climate, including cases in the recent past (Pliocene, Pleistocene and Holocene) and instances predicted in the near future. The theory behind such interpretations is, however, suspect (e.g. Crowley, 1996; Seager et al., 2002), and it may be that other regional or global drivers are more important. The present cool temperate marine climate on the US eastern seaboard north of Cape Hatteras (northernmost North Carolina and Virginia) reflects the influence of cool southward-flowing currents, and a similar influence can be inferred in the Early Pliocene (Johnson et al., 2017). Change to a warm temperate (or marginally subtropical) marine climate in the Late Pliocene has been ascribed to the impingement on the area of warm, northward-flowing currents, assisted by the absence of a barrier equivalent to Cape Hatteras (e.g. Williams et al., 2009). Seasonally resolved oxygen isotope (δ18O) data from bivalve shells reveals, however, that seasonal temperature range was often in excess of that characteristic of the area south of Cape Hatteras (influenced by warm currents), and indicates the continuing influence of cold currents from the north (Johnson et al., 2017). Some isotopic evidence of seasonal temperature range from bivalves is consistent with warm-current influence (Winkelstern et al., 2013), but otherwise the evidence points to a different control (probably global climatic change) on the Late Pliocene warming of marine climate on the US eastern seaboard that is shown by isotopic data for annual average temperature. References: Crowley, T.J. (1996) Pliocene climates: The nature of the problem. Marine Micropaleontology, 27, 3-12. Johnson, A.L.A., Valentine, A., Leng, M.J., Sloane, H.J., Schöne, B.R., Balson, P.S. (2017) Isotopic temperatures from the Early and Mid-Pliocene of the US Middle Atlantic Coastal Plain, and their implications for the cause of regional marine climate change. PALAIOS, 32, 250-269. Seager, R., Battisti, D.S., Yin, J., Gordon, N., Naik, N.H., Clement, A.C., Cane, M.A. (2002) Is the Gulf Stream responsible for Europe's mild winters? Quarterly Journal of the Royal Meteorological Society, 128, 2563-2586. Williams, M., Haywood, A.M., Harper, E.M., Johnson, A.L.A., Knowles, T., Leng, M.J., Lunt, D.J., Okamura, B., Taylor, P.D., Zalaziewicz, J. (2009) Pliocene climate and seasonality in North Atlantic shelf seas. Philosophical Transactions of the Royal Society of London, Series A, 367, 85–108. Winkelstern, I., Surge, D., Hudley, J.W. (2013) Multiproxy sclerochronological evidence for Plio-Pleistocene regional warmth: United States Mid-Atlantic Coastal Plain. PALAIOS, 28, 649-660.
    • Sexual dimorphism in the loud calls of Azara’s owl monkeys (Aotus azarae): evidence of sexual selection?

      Garcia de la Chica, Alba; Huck, Maren; Depeine, Catherine; Rotundo, Marcelo; Adret, Patrice; Fernandez-Duque, Eduardo; University of Derby (Springer Science and Business Media LLC, 2019-11-15)
      Primates use different types of vocalizations in a variety of contexts. Some of the most studied types have been the long distance or loud calls. These vocalizations have been associated with mate defense, mate attraction, and resource defense, and it is plausible that sexual selection has played an important role in their evolution. Focusing on identified individuals of known sex and age, we evaluated the sexual dimorphism in a type of loud calls (hoots) in a population of wild owl monkeys (Aotus azarae) in Argentina. We found evidence of sexual dimorphism in call structure, with females and males only emitting one type of call, each differing in dominant frequency and Shannon entropy. In addition, both age-related and sex-specific differences in call usage were also apparent in response to the removal of one group member. Future acoustic data will allow us to assess if there are individual characteristics and if the structure of hoot calls presents differences in relation to the social condition of owl monkeys or specific sex responses to variants of hoot calls’ traits. This will provide deeper insights into the evolution of vocal mechanisms regulating pair bonding and mate choice strategies in this and other primate species.