229 research outputs found

    Rapaci d'Italia

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    The diets of squacco herons, little egrets, night, purple and grey herons in their italian breeding ranges

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    Les auteurs ont étudié le régime alimentaire des cinq espèces de hérons nichant dans le nord de l'Italie, par identification des proies régurgitées par les poussins lors de dénombrements de héronnières (n = 29), effectués entre le 7 mai et le 27juillet, de 1977 à 1990. Au total, 10 517 items alimentaires ont été collectés et identifiés. Les colonies ont été réparties en quatre régions caractérisées chacune par des milieux de gagnage différents (rizières, cours d'eau, zones humides et lagunes

    Les peuplements de chauves-souris de l’est du lac Turkana, Kenya

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    Les peuplements de chauves-souris ont été étudiés par piégeage sur sept sites sur la bordure Est du lac Turkana, Kénya, région où le statut et la distribution de ces mammifères demeuraient inconnus. Nous avons capturé 97 individus de 13 espèces appartenant à 6 familles : Mégadermatidés (Cardioderma cor), Rhinolophidés (Rhinolophus clivosus), Nyctéridés (Nycteris hispida et N. thebaica), Vespertilionidés (Myotis tricolor, Nycticeinops schlieffeni, Pipistrellus kuhlii et Neoromicia nanus), Molossidés (Chaerephon pumila, Mops condylurus et M. demonstrator), Emballonuridés (Taphozous perforatus et Coleura afra). Lavia frons (Mégadermatidés) a été observé mais non capturé. La présence de bâtiments autour des stations de piégeage a affecté de manière significative le succès du piégeage. L'abondance, la richesse et la diversité se sont avérées variables selon les sites, en relation avec des différences dans la structure écologique des habitats forestiers, semi-désertiques ou insulaires. La richesse et la diversité étaient plus fortes dans les sites protégés et non pâturés que dans ceux non protégés et surpâturés par le bétail. Le surpâturage aurait un effet néfaste sur les peuplements de mammifères, augmentant ainsi les risques de perte de biodiversité dans les zones sauvages

    population trends of wintering waterbirds in lombardy between 2002 and 2013

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    Birds are among the most important biological components of wetlands. They play a key role in their ecology and are an important cultural resource for the public, in part because some species can be legally hunted. The conservation of waterbirds is especially important in terms of land use planning, in light of their ecological, cultural, and economic value. Here we summarize the results of wintering waterbirds censuses carried out in Lombardy between 2002 and 2013, using the standardized International Waterbird Census methodology. Our goals were to identify priority sites for waterbirds; estimate population sizes; define demographic trends; and provide a technical framework for making administrative and legislative decisions on the management and conservation of wetlands and their bird species. Lombardy hosts substantial numbers of wintering waterbirds, and many of its wetlands qualify as areas of conservation interest under Ramsar Convention criteria, as they host >1% of the Italian population of one or more species. Trends for the 20 species of highest conservation or hunting interest showed stable or increasing populations in most cases, with the exception of Black-necked Grebe, Common Pochard, and Eurasian Coot, which instead decreased in 2002-2013. The favourable population trends for most species suggest that the ecological status of Lombardy's wetlands is essentially stable, but it could be improved by simple measures to improve the natural value of the shorelines and bottoms of major lakes and flooded gravel pits. Hunting was one of the main factors affecting the distribution and abundance of wintering waterbirds, which concentrate in protected areas - over 50% of all birds, rising to over 70% for species of conservation interest concentrate there, despite the fact that protected areas only account for 43% of sites surveyed. Overall, protected areas hosted bird densities that were almost seven times higher than those managed primarily for hunting, while mixed-use areas hosted intermediate densities of birds. The presence of protected and unprotected areas within the same wetland mitigates the effects of hunting on bird populations and species diversity, and may help maintain adequate conditions for their conservation

    The spreading of the invasive sacred ibis in Italy

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    The spreading of invasive species in new continents can vary from slow and limited diffusion to fast colonisations over vast new areas. We studied the sacred ibis Threskiornis aethiopicus along a 31-year period, from 1989 to 2019, with particular attention to the first area of release in NW Italy. We collected data on species distribution through observations by citizen science projects, population density by transects with distance method, breeding censuses at colonies, and post breeding censuses at roosts. The birds counted at winter roosts in NW Italy increased from a few tens up to 10,880 individuals in 2019. Sacred ibises started breeding in 1989, with a single nest in north-western Italy. The number of breeders remained very low until 2006, when both overwintering and breeding sacred ibises started to increase exponentially and expand their range throughout northern Italy with isolated breeding cases in central Italy. In 2019, the number of nests had increased to 1249 nests in 31 colonies. In NW Italy, the density of foraging birds averaged 3.9 ind./km2 in winter and 1.5 ind./km2 in the breeding period, with a mean size of the foraging groups of 8.9 and 2.1 birds respectively. Direct field observations and species distribution models (SDM) showed that foraging habitats were mainly rice fields and wetlands. A SDM applied to the whole Italian peninsula plus Sardinia and Sicily showed that the variables best related to the SDM were land class (rice fields and wetlands), altitude, and the temperature seasonality. The areas favourable for species expansion encompass all the plains of Northern Italy, and several areas of Tuscany, Latium, Sardinia, and Apulia

    Gli uccelli della provincia di Novara (Piemonte, Italia): distribuzione, abbondanza e stato di conservazione

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    In questo lavoro viene riportato un elenco commentato degli uccelli noti per la provincia di Novara (1.340 km2) aggiornato al 31/12/2016 e vengono forniti dati di sintesi relativi alle attività di monitoraggio condotte in anni recenti (2009-2016). I dati sono stati raccolti sia attraverso revisione bibliografica sia attraverso attività di ricerca diretta sul campo. L'avifauna della provincia di Novara annovera o ha annoverato (dal 1860 al 2016) 304 specie delle quali 135 nidificanti certe o probabili in tempi recenti (dopo il 2000), 85 di interesse comunitario (Allegato I della Direttiva "Uccelli"), 116 SPEC - Species of European Conservation Concern secondo BirdLife International e 53 inserite nella European Red List of Birds. L'area è di importanza europea e/o nazionale per la nidificazione di specie di interesse conservazionistico quali Egretta garzetta (650-1.100 nidi), Nycticorax nycticorax (200-300 nidi), Botaurus stellaris (5-7 maschi cantori), Ciconia nigra (1-2 coppie), Ciconia ciconia (4-6 coppie), Himantopus himantopus (300-500 coppie), Vanellus vanellus (500-600 coppie), Columba oenas (20-30 coppie), nonché per la migrazione di Philomachus pugnax (5.000-7.000 ind.) e Tringa glareola (500-1.500 ind.). Negli ultimi anni (2009-2016) si segnalano in particolare: la nidificazione accertata per la prima volta nel Novarese di Ardea alba, Galerida cristata e Lullula arborea; il ritorno di Burhinus oedicnemus e Chlidonias niger in periodo riproduttivo dopo decenni di assenza; la colonizzazione da parte di Dryocopus martius degli ambienti forestali di collina e di pianura.</p

    Unexpectedly high levels of cryptic diversity uncovered by a complete DNA barcoding of reptiles of the Socotra Archipelago

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    Few DNA barcoding studies of squamate reptiles have been conducted. Due to the signifi- cance of the Socotra Archipelago (a UNESCO Natural World Heritage site and a biodiversity hotspot) and the conservation interest of its reptile fauna (94% endemics), we performed the most comprehensive DNA barcoding study on an island group to date to test its applicability to specimen identification and species discovery. Reptiles constitute Socotra ' s most impor- tant vertebrate fauna, yet their taxonomy remains under-studied. We successfully DNA-bar-coded 380 individuals of all 31 presently recognized species. The specimen identification success rate is moderate to high, and almost all species presented local barcoding gaps.The unexpected high levels of intra-specific variability found within some species suggest cryptic diversity. Species richness may be under-estimated by 13.8-54.4%. This has implications in the species ranges and conservation status that should be considered for conservation planning. Other phylogenetic studies using mitochondrial and nuclear markers are congruent with our results. We conclude that, despite its reduced length (663 base pairs), cytochrome c oxidase 1, COI, is very useful for specimen identification and for detecting intra-specific diversity, and has a good phylogenetic signal. We recommend DNA barcoding to be applied to other biodiversity hotspots for quickly and cost-efficiently flagging species discovery, preferentially incorporated into an integrative taxonomic framework

    Productivité des aigrettes et hérons nicheurs en six sites asiatiques

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    La production, la taille des oeufs et les conditions corporelles des poussins ont été étudiées chez le Héron garde-boeufs (Bubulcus ibis), l'Aigrette intermédiaire (Egretta intermedia), l'Aigrette garzette (Egretta garzetta), le Crabier chinois (Ardeola bacchus) et le Bihoreau gris (Nycticorax nycticorax) en deux sites de Chine centrale et dans quatre autres au Pakistan. La production en Chine s'est avérée très forte, plus importante qu'au Pakistan, probablement en relation avec une grande disponibilité de zones humides pour l'alimentation. La forme sombre de l'Aigrette garzette de la côte du Pakistan présentait une productivité significativement plus faible que celle des formes blanches
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