2,136 research outputs found

    Assessing the ability of novel ecosystems to support animal wildlife through analysis of diurnal raptor territoriality

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    Novel ecosystems have emerged through human intervention and are rapidly expandingaround the world. Whether they can support animal wildlife has generated considerable controversy.Here we developed a new approach to evaluate the ability of a novel forest ecosystem,dominated by the exotic tree species Eucalyptus globulus, to support animal wildlife inthe medium and long term. To evaluate this ability, we took advantage of the fact that speciesterritory size decreases with increasing habitat quality, and we used territoriality of araptor guild composed of Northern Goshawk (Accipiter gentilis), Eurasian Sparrowhawk(A. nisus) and Common Buzzard (Buteo buteo) as indicator. We compared the territorialityof these species in the novel ecosystem with that in other ecosystems found in the literature.Average distances between con-specifics in the novel ecosystem were similar, or evenshorter, than those in other ecosystems. Average distances between Goshawk con-specificswere among the shortest described in the literature. All three species nested preferably in mixed stands abundant in large exotic trees, with high structural complexity and abundance of native species within the stand. Key factors supporting this diverse and dense raptor community were the special forest management system implemented in the study area and the agricultural matrix located close to forest plantations that complements the supply of prey. Our results suggest that forest management that promotes a complex and suitable forest structure can increase the ability of novel forest ecosystems to support wildlife biodiversity, particularly a diverse nesting community of forest-dwelling raptors and their preys. The results further suggest the suitability of territoriality for assessing this potential of novel ecosystemsMinisterio de Ciencia y TecnologíaUniversidad de AlcaláMinisterio de Educación y Cienci

    Study, preparation and characterization of thiosemicarbazone ligands and their compounds

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    The 20th International Electronic Conference on Synthetic Organic Chemistry session General Organic SynthesisThiosemicarbazones are formed by the condensation of an aldehyde or ketone with a thiosemicarbazide. They have high coordinative capacity given that they have several potential donor atoms through which they can bind to transition metals. This coordinative capacity can be increased if the R1 and R2 substituents include additional donor atoms. In addition, thiosemicarbazones as well as their semicarbazones analogues have considerable biological and pharmacological interest because of their antibacterial, antiviral and antitumor activity. This communication includes the preparation and characterization of a series of thiosemicarcarbazones and their applications in the synthesis of palladium organometallic compoundsWe wish to thank the financial support received from the Xunta de Galicia (Galicia, Spain) under the Grupos de Referencia Competitiva Programme Projects GRC2015/00

    Higher reproductive success of small males and greater recruitment of large females could explain the strong reversed sexual dimorphism (RSD) in the northern goshawk

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    Abstract Reversed sexual dimorphism (RSD), whichoccurs when the female of a species is larger than the male,is the rule for most birds of prey but the exception amongother bird and mammal species. The selective pressuresthat favour RSD are an intriguing issue in animal ecology.Despite the large number of hypotheses proposed to explainthe evolution of RSD, there is still no consensus about themechanisms involved and whether they act on one or bothsexes, mainly because few intrapopulation studies havebeen undertaken and few raptor species have been investigated.Using the strongly size-dimorphic northern goshawk(Accipiter gentilis L.) as a model, we studied a populationwith one of the highest densities of breeding pairs reportedin the literature in order to understand selective pressuresthat may favour RSD. We evaluated life-history processes,including recruitment of adult breeders and reproductivesuccess, and we explored the mechanisms thought to act oneach sex, including hunting efficiency, diet, body conditionand mate choice. We found that smaller males producedmore fledglings than larger ones, but there was no relationshipbetween size and reproductive success for femalesMinisterio de Educación y Cienci

    Prospects for practice-based philosophy of logic

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    We explore prospects for practice-based approaches to logical theory, in particular the link between classical and intuitionistic logic and the inferential structure of traditional practices of representation & argument in science and mathematics. After discussing some key notions about practice, we outline the connection between representation practices and classical logic, and then consider a spectrum of actual practices followed or proposed by (real) scientists. Intuitionistic logic helps to clarify the potential of practice-based approaches for understanding pluralism, and to hammer some key points about the general thesis.Ministerio de Economía y Competitividad FFI2009-1002

    Anything for a quiet life: shelter from mobbers drives reproductive success in a top-level avian predator

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    17 p.Understanding how habitat structure relates to reproductive performance of species can help identify what habitats are of the highest quality for a given species and thereby guide effective management. Here, we compared the influence of prey abundance and the amount of shelter area on the relationship between habitat and breeding performance. We focused on the forest-dwelling northern goshawk Accipiter gentilis in an agroforestry system. Using structural equation modelling, we tested the associations between reproductive performance and three explanatory factors: habitat structure, abundance of food resources or levels of mobbing disturbance, and prey supply to the nest. Our results suggest that habitat structure influences reproductive performance through shelter rather than through prey abundance. During the study period, forested habitats in the breeding territories provided shelter to the goshawk, reducing disturbance by carrion crows Corvus corone, which acted as large, aggressive, social mobbers. Decreased disturbance increased prey supply to the nest, probably because it favored food accessibility and male goshawk foraging efficiency. Habitat was not significantly associated with quality of the breeders, both in terms of body size and seniority in the territories. Our findings suggest that reproductive performance, and therefore habitat quality, may depend more on sheltered access to food resources than on the amount of food available. Our observation that mobbers decrease predator foraging efficiency highlights the possibility of designing effective, socially acceptable predator management strategies to protect sensitive domestic prey.Ministerio para la Transición Ecológica y el Reto DemográficoMinisterio de Educación y CienciaMinisterio de Ciencia e InnovaciónComunidad de MadridUniversidad de Alcal

    Spatial relationships and mechanisms of coexistence between dominant and subordinate top predators

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    Most forest ecosystems contain a diverse community of top-level predators. How these predator species interact, and howtheir interactions infl uence their spatial distribution is still poorly understood.Here we studied interactions among top predators in a guild of diurnal forest raptors in order to test the hypothesisthat predation among competing predators (intraguild predation) signifi cantly aff ects the spatial distribution of predatorspecies, causing subordinate species to nest farther away from the dominant ones.Th e study analyzed a guild in southwestern Europe comprising three raptor species. For 8 years we studied the spatialdistribution of used nests, breeding phenology, intraguild predation, territory occupancy, and nest-builder species andsubsequent nest-user species.Th e subordinate species (sparrowhawk Accipiter nisus ) nested farther away from the dominant species (goshawk A. gentilis), which preyed on sparrowhawks but not on buzzards Buteo buteo , and closer to buzzards, with which sparrowhawks donot share many common prey. Th is presumably refl ects an eff ort to seek protection from goshawks. Th is potential positiveeff ect of buzzards on sparrowhawks may be reciprocal, because buzzards benefi t from old sparrowhawk nests, which buzzardsused as a base for their nests, and from used sparrowhawk nests, from which buzzards stole prey. Buzzards occasionallyoccupied old goshawk nests.Universidad de Alcalá de Henare

    Prey preferences and recent changes in diet of a breeding population of the Northern Goshawk Accipiter gentilis in Southwestern Europe

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    Capsule: Northern Goshawk Accipiter gentilis diet has changed significantly since the 1980s,probably due to changes in populations of preferred prey species.Aims and methods: To assess changes to the breeding season diet of the Northern Goshawk insouthwest Europe over three decades. We examined prey remains at and around nests andassessed avian prey availability using point count surveys.Results: During 2008&#-11, Goshawks mainly ate birds, with Feral Pigeons Columba livia f. domesticabeing the most important prey species. Goshawks preferred prey of 100&;8722#400 g and forest preyspecies to non-forest species. Goshawk diet has changed significantly over recent decades: 22%of current prey items belong to species that were not part of the diet in the 1980s. We suggestthat these dietary changes reflect changes in the abundance of prey species of the preferredsize caused by changes in land use leading to an increase in forest cover, new prey speciescolonization and changes in the abundance and management of domestic prey.Conclusion: This study emphasizes that major transformations occurring in agroforestry systemsare affecting the main preferred prey of important forest predators, which may haveconsequences for conservation of both the predators and their prey

    Functionalized thiosemicarbazone ligands and their complexes

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    The 20th International Electronic Conference on Synthetic Organic Chemistry session General Organic SynthesisThe purpose of this work is the design, synthesis and characterization of thiosemicarbazone ligands bearing a phenyl boronic acid functionality. The main interest is the synthesis of organopalladium compounds with the boronic acid included within the corresponding molecule. These could lead to further modification of the properties of the organometallic species applicable to the Suzuki-Miyaura reaction. The ligands were prepared by reaction of acetylphenylboronic acid with several thiosemicarbazides. The compounds were characterized by IR, 1H and 31P NMR spectroscopyWe wish to thank the financial support received from the Xunta de Galicia (Galicia, Spain) under the Grupos de Referencia Competitiva Programme Projects GRC2015/009

    Synthesis of iminophosphoranes as ligands for organometallic compounds

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    Iminophosphoranes are organic compounds of general composition R3P=NR and can be considered as nitrogen analogues to phophorus ylides. They can be obtained by the Staudinger and Kirsanov reactions. This compounds have multiple applications: they can be used as intermediates in reactions such as the Aza-Wittig, as a protecting group for amines or as a ligands for coordinated or cyclometallated compounds. The P=N bond is highly polarized, so that the nitrogen bears a partial negative charge. This feature makes them act as σ-donors with only minor π-acceptor properties, so when forming coordination compounds they can be displaced by other ligandsWe wish to thank the financial support received from the Xunta de Galicia (Galicia, Spain) under the Grupos de Referencia Competitiva Programme Projects GRC2015/00
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