1,721,075 research outputs found

    Census of the Sicilian rock partridge Alectoris graeca whitakeri population in ZPS ITA010029 Monte Cofano, Capo San Vito and Monte Sparagio

    Full text link
    During the project "LIFE09 NAT/IT/000099-SICALECONS-Urgent actions for the conservation of Alectoris graeca whitakeri", this species was censused in the ZPS ITA010029 Monte Cofano, Capo San Vito and Monte Sparagio (Trapani province, Sicily) with playback technique between March and April 2011. Superimposing a UTM grid of 1 km mesh on the study area produced cells of 100 hectares. Using a GPS satellite receiver we reached, where possible, the centre of each cell from where the cospecific call was broadcasted. A total of 163 listening stations were implemented. Using software GIS ARCMAP 10.0 (ESRI) presence data were interpolated with vegetational and phytosociological maps (CORINE) to establish rock partridge's suitable area. The range of the rock partridge in the ZPS was calculated to be 9,893 hectares, corresponding to approximately 65% of the ZPS. A total of 29 individuals were counted, corresponding to 5 pairs and 19 calling males.The Sicilian rock partridge population in the ZPS was estimated to be 66 pairs. Density values in the ZPS were lower than those reported for other areas. In the ZPS highest density was observed in Zingaro Reserve, where poaching seems to be less frequent compared to other areas of ZPS and where burning has not been recorded for years. © 2013 CISO - Centro Italiano Studi Ornitologici

    Mercury, Lead and Copper in Feathers and Excreta of Small Passerine Species in Relation to Foraging Guilds and Age of Feathers

    No full text
    In the present study excreta and feathers of five species of adult passerine birds from Montepulciano wetland (Siena, Italy) were assayed for trace elements between January and August 2006. Lead concentrations varied from 16.31 to 26.50 mg/kg and were found strictly related to the age of feathers. Copper levels were found to be high mainly in insectivorous birds (9.68 mg/kg) and were probably influenced by local use of copper-based agricultural fungicides. Mercury accumulation in feathers varied between species from 0.08 to 0.73 mg/kg. The role of feeding habits on trace elements levels in feathers and excreta is discussed. © 2009 Springer Science+Business Media, LLC

    Biological quality of running waters in protected areas: the influence of size and land use

    No full text
    There are still substantial questions about whether protected areas affect the quality and biodiversity of surface waters within their borders. In this study, the size and land use of 19 protected areas of Latium Region (central Italy) were related to the biological quality of 32 streams running inside them. Additionally, the biological quality of 18 out of the 32 streams was compared with the quality recorded on the same streams outside the boundaries of the protected areas. The biological quality was assessed using the Extended Biotic Index, which indicates the macroinvertebrate community health. The quality of 32 study streams running through the protected areas was not related to the size of these areas, but it did reflect land use. On average, the 18 study sites inside protected areas had biological quality similar to external control sites. In the protected areas, the biological quality of streams was higher than for the same streams in the surrounding territory provided that anthropogenic changes were fewer. These data indicate that the creation of protected areas per se does not increase freshwater biodiversity and that land use has a major impact on the biological quality of the stream in a protected area. As a consequence, a higher number of reserves or landscape designations specifically created for aquatic conservation is necessary and recovery programs aimed at restoring physical habitats and reducing sources of impact to aquatic life have to be pursued. Also, where the anthropogenic impact is high (e.g., as in the case of strongly urbanised areas), the creation of effective protected areas might improve the biological quality of water courses

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Spatial negative priming in bilingualism

    No full text
    Balanced bilinguals have been shown to have an enhanced ability to inhibit distracting information. In this study, we investigated the hypothesis that the bilinguals' efficiency in inhibitory control can be advantageous in some conditions, but disadvantageous in others-for example, negative priming conditions, in which previously irrelevant information becomes relevant. Data collected in a target-stimulus locating task from 29 early bilingual adults and 29 age-matched monolinguals showed that the bilinguals' greater inhibition of irrelevant spatial information (i.e., the position of a distractor stimulus) resulted in a smaller effect of the distractor presence (i.e., a smaller difference in error rates in trials with and without distractors) and a larger negative priming effect (i.e., a larger difference between the error rates shown in trials wherein the target position corresponded to the position of the previous-trial distractor and trials wherein the target was presented in a previously vacant position). These findings support the hypothesis of specific nonlinguistic cognitive effects of bilingualism on inhibitory control functions, which are not necessarily reflected in cognitive advantages
    corecore