760 research outputs found

    An integrated analysis of micro- and macro-habitat features as a tool to detect weather-driven constraints: a case study with cavity nesters

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    The effects of climate change on animal populations may be shaped by habitat characteristics at both micro- and macro-habitat level, however, empirical studies integrating these two scales of observation are lacking. As analyses of the effects of climate change commonly rely on data from a much larger scale than the microhabitat level organisms are affected at, this mismatch risks hampering progress in developing understanding of the details of the ecological and evolutionary responses of organisms and, ultimately, effective actions to preserve their populations. Cavity nesters, often with a conservation status of concern, are an ideal model because the cavity is a microenvironment potentially different from the macroenvironment but nonetheless inevitably interacting with it. The lesser kestrel (Falco naumanni) is a cavity nester which was until recently classified by as Vulnerable species. Since 2004, for nine years, we collected detailed biotic and abiotic data at both micro- and macro-scales of observation in a kestrel population breeding in the Gela Plain (Italy), a Mediterranean area where high temperatures may reach lethal values for the nest content. We show that macroclimatic features needed to be integrated with both abiotic and biotic factors recorded at a microscale before reliably predicting nest temperatures. Among the nest types used by lesser kestrels, we detected a preferential occupation of the cooler nest types, roof tiles, by early breeders whereas, paradoxically, late breeders nesting with hotter temperatures occupied the overheated nest holes. Not consistent with such a suggested nest selection, the coolest nest type did not host a higher reproductive success than the overheated nests. We discussed our findings in the light of cavity temperatures and nest types deployed within conservation actions assessed by integrating selected factors at different observation scales

    Functional spatial contextualisation of the effects of multiple stressors in marine bivalves

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    Abstract. Many recent studies have revealed that the majority of environmental stressors experienced by marine organisms (ocean acidification, global warming, hypoxia etc.) occur at the same time and place, and that their interaction may complexly affect a number of ecological processes. Here, we experimentally investigated the effects of pH and hypoxia on the functional and behavioural traits of the mussel Mytilus galloprovincialis, we then simulated the potential effects on growth and reproduction dynamics trough a Dynamic Energy Budget (DEB) model under a multiple stressor scenario. Our simulations showed that hypercapnia had a remarkable effect by reducing the maximal habitat size and reproductive output differentially as a function of the trophic conditions, where modelling was spatially contextualized. This study showed the major threat represented by the hypercapnia and hypoxia phenomena for the growth, reproduction and fitness of mussels under the current climate change context, and that a mechanistic approach based on DEB modelling can illustrate complex and site-specific effects of environmental change, producing that kind of information useful for management purposes, at larger temporal and spatial scales.</p

    Energetics, Particle Capture and Growth Dynamics of Benthic Suspension Feeders

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    Marine benthic communities are dominated by suspension feeders, including those actively pumping water, passively encountering particles, or some combination of the two. The mechanisms by which particles are encountered and retained are now well known for a range of water flow conditions and organism morphologies. Recent research has attempted to quantify the energetic components of suspension feeding, including intake of particles, pumping rates, and metabolic costs of these activities. Energetic models depend strongly on environmental conditions, including temperature, flow speed, and food availability, for example. The effects of these variables have been combined for realistic scenarios using dynamic energy budget (DEB) models, and related models to examine components of fitness (growth, reproduction, population increase), for both existing conditions and for conditions expected for future environments. Detailed examples are provided from recent research on bivalve mollusks, cnidarians including sea anemones and corals, and barnacles. These examples cover several major phyla that are often important components of intertidal and subtidal benthic communities. All common phyla of benthic suspension feeders are discussed, though less extensively, especially given the paucity of energetics studies for some of these phyla

    Explicit recognition of emotional facial expressions is shaped by expertise: evidence from professional actors

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    Can reading others' emotional states be shaped by expertise? We assessed processing of emotional facial expressions in professional actors trained either to voluntary activate mimicry to reproduce character's emotions (as foreseen by the “Mimic Method”), or to infer others' inner states from reading the emotional context (as foreseen by “Stanislavski Method”). In explicit recognition of facial expressions (Experiment 1), the two experimental groups differed from each other and from a control group with no acting experience: the Mimic group was more accurate, whereas the Stanislavski group was slower. Neither acting experience, instead, influenced implicit processing of emotional faces (Experiment 2). We argue that expertise can selectively influence explicit recognition of others' facial expressions, depending on the kind of “emotional expertise”

    Amalia Bettini

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    ‘Amorosa’, then leading actress, the most appreciated and sought after actress of the 1830s. She had an intense and longstanding relationship with the poet Giuseppe Gioachino Belli. In the latter years of her career she performed in the Compagnia Reale Sarda (The Royal Sardinian Company)

    Thermal adaptation and physiological responses to environmental stress in tunicates

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    Understanding the multifaceted nature of environmental fluctuations is crucial to predicting the physiological adjustments utilised by organisms in resisting or adapting to changes over time. Here we investigate the effects of 2 environmental stressors on tunicates, whose fitness can have important repercussions on the quality of habitat. Specifically, we report respiration rate (RR), clearance rate (CR), and assimilation efficiency (AE) of the ascidian Styela plicata in response to a range of temperatures and varying food availability. Temperature-dependent RR was observed only within a portion of the thermal window of the species. Significant differences in clearance rates were detected among organisms fed with varying algal concentrations, while no significant influence of food concentrations on AE was observed. This plasticity of the physiological rates and the development of ubiquitous mechanisms such as temperature-insensitive aerobic metabolism suggest a competitive advantage of this group. Such knowledge may allow for more accurate predictions of the physiological and evolutionary mechanisms driving current and future distribution of this species

    Planning conservation actions by investigating nest preferences and biotic and abiotic factors within lesser kestrel (Falco naumanni) colonies

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    The lesser kestrel (Falco naumanni) was until recently classified as a Vulnerable species. It is a cavity nester species finding proper nest sites in natural cliff holes or, as more frequently today, cavities found within rural buildings. These are often abandoned and therefore, with no maintenance, the main structures of kestrel colonies have been collapsing across years. To counterbalance the reduced availability of nesting sites for kestrels, and because of their unfavorable conservation status, artificial nest boxes have been placed in several areas of their breeding range. On our study site, the Gela Plain in Sicily, as on other Mediterranean breeding areas, high temperatures may reach lethal values for the nest content. Since 2004, we collected biotic and abiotic data at macro- and micro-scales to integrate an analysis aiming to predict nest temperatures in different nest types. Paradoxically, early breeders preferentially occupied the coolest nest types, the roof tiles, whereas late breeders, starting their nesting attempts with hotter temperatures, occupied the overheated nest boxes. We discuss our findings in the light of planning proper and efficient conservation actions, such as providing different nest types, by pondering whether kestrel nest preferences might either sort into ecological traps or be the result of ecological limitations

    Response of captive seabass and seabream as behavioural indicator in aquaculture

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    Welfare of cultivate fish at high-density represents an important concern for modern aquaculture. The behaviour of European seabass (Dicentrarchus labrax) and seabream (Sparus aurata) reared in cages was studied in a fish farm of northern Sardinia (Italy) in autumn 2006 to test whether captive condition had an effect on the movement patterns of these two species.Video images recorded before, during and after the manual feeding distribution allowed us to collect data on different behaviours of captive fish. Thus, behaviours indicating the position of fish in the water column, swimming direction and possible aggressive behaviours (aggression, direction change and collision) showed juveniles and adults of seabass and seabream were overall affected by feeding rhythms and captive overcrowding. Seabream had a major tendency to swim towards the bottom and higher frequency of horizontal swimming and collisions than seabass. The overall behavioural difference between two species was explained in terms of their differences in ecological features in the wild
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