91 research outputs found

    Population and individual-scale responses to patch size, isolation and quality in the hazel dormouse

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    Patch size, isolation and quality are key factors influencing species persistence in fragmented landscapes. However, we still lack a detailed understanding of how these variables exert their effects on populations inhabiting fragmented landscapes. At which ecological scale do they have an effect (e.g., individuals versus populations) and, on which demographic parameters? Answering these questions will identify the mechanisms that underlie population turnover rather than solely predicting it based on proxies (e.g., presence/absence data). We report the results of a large-scale, three-year study focused on the relative effects of patch size, isolation and quality on individuals and populations of an arboreal rodent, the hazel dormouse (Muscardinus avellanarius). We examined 30 sites nested within three landscapes characterized by contrasting levels of habitat amount and habitat quality (food resources). We quantified the effects of patch size and quality on the response of individuals (survival and litter size) and populations (density and colonization/extinction dynamics). We identified demographic mechanisms which led to population turnover. Habitat quality positively affected survival (not litter size) and population density (measured through an index). We infer that the decline in survival due to patch quality reduced patch recolonization rather than increasing extinction, while extinction was mainly affected by patch size. Our findings suggest that the effect of patch quality on individual and population parameters was constrained by the physical structure of the surrounding landscapes. At the same time, our results highlight the importance of preserving habitat quality to help the persistence of entire systems of patches

    Protein hunger of the feed sector: the alternatives offered by the plant world

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    The expected future demand for highly nutrient animal food products will push the animal production system to search for new sources of high-quality protein feedstuffs. In this scenario, economic and environmental issues will have to be considered while reducing the competition with the plant-based human food chains. Legume grains and some oilseed cakes, by-products from the oil industry, are the main protein sources for ruminants and terrestrial monogastrics such as pigs and poultry. Their relevant role will hold in the next decades, but it is necessary to increase the diversification of sources that can be grown profitably throughout the world, including European countries. Microalgae are a promising source of protein and other nutrients for animal feeding. However, an amazing richness of biologically active substances makes these organisms very interesting as feed ingredients, as their role go far beyond the supply of nutrients. Due to the limited usage of microalgae as human foodstuffs or food ingredients, low competition between microalgae-based feed and food chains is predictable. This review aims to synthesise current knowledge on minor pulses and other protein-rich plant products and microalgae, as alternative ingredients to the conventional animal protein sources, focussing on their production, availability, and nutritional values. Points of strength, weakness, opportunity and threat related to the use of these protein sources in animal feeding are separately analysed through a SWOT approach to underlie future needs in terms of research and/or technological development that could help valorise these nutrient sources as feed ingredients

    Studies of inclusive four-jet production with two b-tagged jets in proton-proton collisions at 7 TeV

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    Monitoring Exotic Beetles with Inexpensive Attractants: A Case Study

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    Simple SummaryDetecting and monitoring exotic and invasive beetles is a complex activity, and multiple species still manage to evade controls. Citizen science can be an important adjunct in alien species monitoring programs, but to have a greater chance of success, it must employ traps and attractants that are easy to gather and use. Bottle traps baited with food products are successfully used during long term faunistic surveys, and the same methodology can be adapted to alien species detection and monitoring. In this article, we tested the use of bottles baited with apple cider vinegar, red wine, and 80% ethyl alcohol in capturing exotic and invasive beetles in the surroundings of Malpensa Airport (Italy). The traps proved effective, and in the traps with vinegar as an attractant, they captured four out of five invasive Nitidulidae, as well as the only invasive Scarabaeidae present in the area. Popillia japonica's response to apple cider vinegar is documented for the first time and suggests the use of this attractant in monitoring surveys for this species, especially if supported by citizen science programs. The substantial reduction in the activity time of the traps seems to have considerably reduced collateral catches of native fauna.Detecting and monitoring exotic and invasive Coleoptera is a complex activity to implement, and citizen science projects can provide significant contributions to such plans. Bottle traps are successfully used in wildlife surveys and can also be adapted for monitoring alien species; however, a sustainable, large scale trapping plan must take into account the collateral catches of native species and thus minimize its impact on local fauna. In the present paper, we tested the use of bottles baited with standard food products that can be purchased in every supermarket and immediately used (apple cider vinegar, red wine, and 80% ethyl alcohol) in capturing exotic and invasive beetles in the area surrounding Malpensa Airport (Italy). In particular, we reduced the exposition type of the traps in each sampling round to three days in order to minimize native species collecting. We found a significant effect of the environmental covariates (trap placement, temperature, humidity, and forest type) in affecting the efficiency in catching target beetles. Nearly all invasive Nitidulidae and Scarabaeidae known to be present in the area were captured in the traps, with apple cider vinegar usually being the most effective attractant, especially for the invasive Popillia japonica

    L (2011) Identification of putative wintering areas and ecological determinants of common house martin (Delichon urbicum) and common swift (Apus apus) breeding in northern Italy. Avian Cons Ecol 6(1):3 http://dx.doi. org/10.5751/ACE-00439-060103 Arriero E

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    ABSTRACT. To identify the causes of population decline in migratory birds, researchers must determine the relative influence of environmental changes on population dynamics while the birds are on breeding grounds, wintering grounds, and en route between the two. This is problematic when the wintering areas of specific populations are unknown. Here, we first identified the putative wintering areas of Common House-Martin (Delichon urbicum) and Common Swift (Apus apus) populations breeding in northern Italy as those areas, within the wintering ranges of these species, where the winter Normalized Difference Vegetation Index (NDVI), which may affect winter survival, best predicted annual variation in population indices observed in the breeding grounds in 1992-2009. In these analyses, we controlled for the potentially confounding effects of rainfall in the breeding grounds during the previous year, which may affect reproductive success; the North Atlantic Oscillation Index (NAO), which may account for climatic conditions faced by birds during migration; and the linear and squared term of year, which account for nonlinear population trends. The areas thus identified ranged from Guinea to Nigeria for the Common House-Martin, and were located in southern Ghana for the Common Swift. We then regressed annual population indices on mean NDVI values in the putative wintering areas and on the other variables, and used Bayesian model averaging (BMA) and hierarchical partitioning (HP) of variance to assess their relative contribution to population dynamics. We re-ran all the analyses using NDVI values at different spatial scales, and consistently found that our population of Common House-Martin was primarily affected by spring rainfall (43%-47.7% explained variance) and NDVI (24%-26.9%), while the Common Swift population was primarily affected by the NDVI (22.7%-34.8%). Although these results must be further validated, currently they are the only hypotheses about the wintering grounds of the Italian populations of these species, as no Common House-Martin and Common Swift ringed in Italy have been recovered in their wintering ranges. RÉSUMÉ. Afin de cerner les causes de dĂ©clin des oiseaux migrateurs, les scientifiques doivent dĂ©terminer l'influence relative des changements environnementaux sur la dynamique des populations, tant sur les aires de reproduction et d'hivernage que sur les haltes migratoires. Cette dĂ©marche est particuliĂšrement problĂ©matique lorsque les aires d'hivernage de populations spĂ©cifiques sont inconnues. Dans la prĂ©sente Ă©tude, nous avons d'abord dĂ©terminĂ© les aires d'hivernage prĂ©sumĂ©es des populations d'Hirondelle de fenĂȘtre (Delichon urbicum) et de Martinet noir (Apus apus) qui se reproduisent dans le nord de l'Italie; ces aires prĂ©sumĂ©es correspondent aux endroits, dans l'ensemble de l'aire d'hivernage de ces espĂšces, oĂč l'indice de vĂ©gĂ©tation par diffĂ©rence normalisĂ©e (IVDN) -qui affecte peut-ĂȘtre la survie hivernaleexpliquait le mieux la variation annuelle des indices de population observĂ©s sur les aires de reproductio

    Identification of Putative Wintering Areas and Ecological Determinants of Population Dynamics of Common House-Martin (Delichon urbicum) and Common Swift (Apus apus) Breeding in Northern Italy

    No full text
    To identify the causes of population decline in migratory birds, researchers must determine the relative influence of environmental changes on population dynamics while the birds are on breeding grounds, wintering grounds, and en route between the two. This is problematic when the wintering areas of specific populations are unknown. Here, we first identified the putative wintering areas of Common House-Martin (Delichon urbicum) and Common Swift (Apus apus) populations breeding in northern Italy as those areas, within the wintering ranges of these species, where the winter Normalized Difference Vegetation Index (NDVI), which may affect winter survival, best predicted annual variation in population indices observed in the breeding grounds in 1992-2009. In these analyses, we controlled for the potentially confounding effects of rainfall in the breeding grounds during the previous year, which may affect reproductive success; the North Atlantic Oscillation Index (NAO), which may account for climatic conditions faced by birds during migration; and the linear and squared term of year, which account for nonlinear population trends. The areas thus identified ranged from Guinea to Nigeria for the Common House-Martin, and were located in southern Ghana for the Common Swift. We then regressed annual population indices on mean NDVI values in the putative wintering areas and on the other variables, and used Bayesian model averaging (BMA) and hierarchical partitioning (HP) of variance to assess their relative contribution to population dynamics. We re-ran all the analyses using NDVI values at different spatial scales, and consistently found that our population of Common House-Martin was primarily affected by spring rainfall (43%-47.7% explained variance) and NDVI (24%-26.9%), while the Common Swift population was primarily affected by the NDVI (22.7%-34.8%). Although these results must be further validated, currently they are the only hypotheses about the wintering grounds of the Italian populations of these species, as no Common House-Martin and Common Swift ringed in Italy have been recovered in their wintering ranges

    New Evidence on the Linkage of Population Trends and Species Traits to Long-Term Niche Changes

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    Despite the assessment of long-term niche dynamics could provide crucial information for investigating species responses to environmental changes, it is a poorly investigated topic in ecology. Here, we present a case study of multi-species niche analysis for 71 common breeding birds in Northern Italy, exploring long-term niche changes from 1992 to 2017 and their relationship with both population trends and species traits. We (i) quantified the realized Grinnellian niche in the environmental space, (ii) compared variations in niche breadth and centroid, (iii) tested niche divergence and conservatism through equivalency and similarity tests, (iv) calculated niche temporal overlap, expansion and unfilling indices, and (v) investigated their association with both population changes and species traits. Results supported niche divergence (equivalency test) for 32% of species, although two-thirds were not supported by the similarity test. We detected a general tendency to adjust the niche centroids towards warmer thermal conditions. Increasing populations were positively correlated with niche expansion, while negatively correlated with niche overlap, albeit at the limit of the significance threshold. We found moderate evidence for a non-random association between niche changes and species traits, especially for body size, clutch size, number of broods per year, inhabited landscape type, and migration strategy. We encourage studies correlating long-term population trends and niche changes with species traits’ information and a specific focus on cause-effect relationship at both the single and multiple-species level

    Hierarchies and Dominance Behaviors in European Pond Turtle (Emys orbicularis galloitalica) Hatchlings in a Controlled Environment

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    Few species of reptiles are known to establish stable social structures and among these, chelonians provided scarce and conflicting results. Moreover, studies on turtles are usually performed on adult individuals. In this study, we checked whether and when hatchlings of the European Pond Turtle (Emys orbicularis galloitalica) established stable hierarchical structures in their first year of life, whether hierarchies were stable in time and how steady they were. We also verified whether social ranks were associated to the individuals’ size. We observed dyadic interactions daily within three small groups of turtles reared in a controlled environment for seven months. After two months, the hatchlings started to interact and progressively established stable hierarchical structures. However, the effectiveness of the three types of observed aggressive behaviors in reversing social ranks was low and the resulting hierarchies were flat. We did not find a significant effect of the turtles’ size on their interactions’ outcome and hierarchy structure. Our results provide clear evidence of the development and the characteristics of social behaviors in young reptiles in captivity. This study could be a starting point for investigating social structures in wild populations
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