20 research outputs found

    Exotic lagomorph may influence eagle abundances and breeding spatial aggregations: A field study and meta- analysis on the nearest neighbor distance

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    The introduction of alien species could be changing food source composition, ultimately restructuring demography and spatial distribution of native communities. In Argentine Patagonia, the exotic European hare has one of the highest numbers recorded worldwide and is now a widely consumed prey for many predators. We examine the potential relationship between abundance of this relatively new prey and the abundance and breeding spacing of one of its main consumers, the Black-chested Buzzard-Eagle (Geranoaetus melanoleucus). First we analyze the abundance of individuals of a raptor guild in relation to hare abundance through a correspondence analysis. We then estimated the Nearest Neighbor Distance (NND) of the Black-chested Buzzard-eagle abundances in the two areas with high hare abundances. Finally, we performed a metaregression between the NND and the body masses of Accipitridae raptors, to evaluate if Black-chested Buzzard-eagle NND deviates from the expected according to their mass. We found that eagle abundance was highly associated with hare abundance, more than with any other raptor species in the study area. Their NND deviates from the value expected, which was significantly lower than expected for a raptor species of this size in two areas with high hare abundance. Our results support the hypothesis that high local abundance of prey leads to a reduction of the breeding spacing of its main predator, which could potentially alter other interspecific interactions, and thus the entire community.Fil: Barbar, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Ignazi, Gonzalo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Hiraldo, Fernando. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; EspañaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentin

    Farm diversification decision-making stages

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    Ūkio diversifikacijos sprendimo priėmimo modeliavimas yra aktuali mokslinė problema, nes ūkio diversifikacijos sprendimo realizavimo tyrimai nėra dažni. Straipsnio tikslas – pateikti pagrindinius ūkio diversifikacijos sprendimo priėmimo etapus. Teoriniam ūkio diversifikacijos sprendimo priėmimo modeliui patikrinti naudota ekspertų apklausa. Buvo apklausta 14 ekspertų. Nustatyta, kad ūkio diversifikacijos tikslų susiejimas su identifikuotų galimybių išorinėje aplinkoje ar ūkininko ūkyje išnaudojimu, sukuria ūkio vystymo prielaidas. Identifikuoti nauji ūkio diversifikacijos sprendimo alternatyvų formulavimo būdai. Patvirtiti šie ūkio diversifikacijos sprendimo alternatyvų vertinimo kriterijai: sprendimo išorinės įgyvendinamumo galimybės, vidinės įgyvendinamumo galimybės, sinerginiai ryšiai, rizikingumas. Mokymasis turėtų tapti permanentiniu procesu, jis aktualus visuose ūkio diversifikacijos sprendimo priėmimo etapuose.That the farmer's decision to diversify the farm will achieve its objectives, it must be properly designed. Modeling of farm diversification decision–making is a scientific problem, because tests of the farm diversification decision realization are not common in the scientific literature. It is achieved article aim – identified the main farm’s diversification decision–making stages. The expert survey was used to check the theoretical diversification farmer’s decision–making model. 14 experts were interviewed. The study found that the farm diversification objectives connection with identified opportunities in external environment or with farm exploitation creates preconditions for farm development. Expert interviews helped identify new formulation methods of farm diversification solution alternatives. The farm diversification decision alternatives are important to assess according to following criteria: decision outside feasibility, internal feasibility, synergies, riskiness. Learning should become a permanent process

    Landscape homogenization due to agricultural intensification disrupts the relationship between reproductive success and main prey abundance in an avian predator

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    Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance.Peer reviewe

    KAIMO BENDRUOMENIŲ JUDĖJIMAS LIETUVOJE NAUJŲJŲ SOCIALINIŲ JUDĖJIMŲ PERSPEKTYVOJE

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    After Lithuania regained the independence, the state confronted with many political, social, economic, and cultural challenges, which led to changes of norms, values, forms of activities and consciousness of citizens. Changing situation lead to the marginalization of rural areas, the rural community movement raised. The main reason for the rising movement was dissatisfaction about current situation and willingness to change it using communities’ resources. This movement is allied to new social movements, which arose in 1960 in Western world. For the creation of postindustrial rural areas the paradigm of innovative, sustainable, inclusive rural development determines that new theories, explaining transformations, are necessary. The aim of this research is to identify correspondence of Lithuanian rural community movement to new social movement theory. Scientific literature, related documents, and secondary statistical data were analysed, the theoretical framework of six dimensions was created and applied. The research results confirmed that rural community in Lithuania is to be viewed as a new social movement with some features of traditional movements. These findings may be useful for increasing the awareness about social transformations in rural areas.Atkurta Lietuvos valstybė susidūrė su daugybe politinių, socialinių, ekonominių, kultūrinių iššūkių, inspiravusių visuomenės normų, aktyvumo ir žmonių sąmoningumo kaitą. Kaip atsakas į besikeičiančią situaciją kaime, kilo kaimo bendruomenių judėjimas. Pagrindinis kylančio judėjimo tikslas – nepasitenkinimas esama padėtimi, noras keisti gyvenimo kokybę savo jėgomis, artimas Vakarų pasaulyje susiformavusiems naujiesiems socialiniams judėjimams. Poindustrinio kaimo kūrimui svarbi inovatyvaus, tvaraus ir įtraukaus kaimo vystymo paradigma suponuoja, kad šiandienos kaimo tyrimams būtinos naujos kokybinės dimensijos ir teorijos, talkinančios aiškinant vykstančias transformacijas. Šio straipsnio tikslas – įvertinti Lietuvos kaimo bendruomenių judėjimo bruožų atitikimą naujiesiems socialiniams judėjimams. Tikslui pasiekti remiantis pagrindiniais naujųjų socialinių judėjimų bruožais sukurtas ir pritaikytas šešių dimensijų modelis. Tyrimo rezultatai patvirtina daugumos kaimo bendruomenės veiklos bruožų panašumą su naujaisiais socialiniais judėjimais, inspiruojančiais gyvenimo kokybės pokyčius kaimo vietovėse. Tyrimo prieiga naudinga kaip nauja kokybinė dimensija, gilesniam vykstančių transformacijų kaime pažinimui
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