Volume 34 - N. 1
June 2010

Avocetta
Volume 34 - N. 1



  1. La biodiversità nel 2010: situazione italiana

    Massa B.

    Abstract     Read Article       Download
    24 64
  2. Variation in diet composition of wintering waterfowlamong Greek wetlands

    Karmiris I., Kazantzidis S., Papachristou T. G.

    Abstract     Read Article       Download
    15 47

    The aim of this study was to determine the diet composition of wintering waterfowl, and assess its variation among Greek wetlands. Digestive tracts (oesophagus, proventriculus and gizzards) of Gadwall Anas strepera, Eurasian Wigeon Anas penelope, Eurasian
    Teal Anas crecca, Mallard Anas platyrhynchos, Northern Shoveler Anas clypeata, Northern Pintail Anas acuta and Common Coot Fulica
    atra were collected in four Greek wetlands (Evros Delta, Lake Vistonida, Aliakmon-Axios Delta and Messolonghi Lagoon), during two
    wintering periods from October 2004 to March 2006. Diet composition was evaluated using the percentage of occurrence and the aggregated percent dry weight methods. Gadwall and Wigeon were primarily herbivorous (both more than 95% dry weight), Teal and Mallard
    mostly relied upon seeds for food (60-75% dry weight), whereas Shoveler, Pintail and Coot consumed elevated quantities of invertebrates
    (27.4%, 16.8%, and 31.2% dry weight respectively). Scirpus consumption by Teal and Mallard was lower in Messolonghi Lagoon than
    in the other wetlands. Conversely, increased quantities of Ruppia spp. and invertebrates were recorded in waterfowl diets (except Teal)
    in Messolonghi Lagoon. These fndings may be attributed to the variation in food availability among study areas, thus management plans
    should be focused both upon the targeted bird species and the particular wetland separately. In general, since studied species exhibit considerably forage plasticity, providing increased habitat heterogeneity seems to be the best management approach for wintering waterfowl
    in Greece, at least under their dietary needs’ aspect.

  3. In memoria di Sergio Frugis

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    41 145
  4. Use of pigeons as bioindicators of air pollution fromheavy metals at Rabat-Salé (Morocco)

    Elabidi A., Fekhaoui M., Ghouli A., Piervittori R., Yahyaoui A.

    Abstract     Read Article       Download
    18 71

    Adult Columba livia pigeons were used as bioindicators of atmospheric pollution by heavy metals, from different sources
    (road traffc, earthenware workshops). Concentrations in pigeon tissues varied according to metals. Lead and cadmium showed higher
    accumulation in kidneys, while zinc was the found in whole organs. Except for Oulja, where lead is commonly used in earthenware production, lead and cadmium were accumulated according to the density of road traffc, thus the highest lead concentrations were found in
    the town centre, followed by Kamra where car traffc is moderate, and with the lowest concentrations of lead in rural areas. On average,
    high concentrations of cadmium were observed in the kidneys of pigeons in the town centre, and a lower content ratio (25 times) was
    found in rural areas (Allal Behraoui). The low metal concentrations in the pigeons blood and organs was due to the limited presence of
    industry in Rabat-Salé.

  5. I Picidi lungo il corso del fume Isonzo: analisiquantitativa e scelta del sito di nidifcazione

    Tofful M., Sponza S.

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    18 143

    This study examined nest-site selection of four woodpecker species living in the floodplain forests of the Isonzo river (Gorizia). 14 plots were examined for a total area of 278 ha. We estimated the number of pairs for the whole study area: 60 of the Great Spotted Woodpecker Dendrocopos major, 30 of the Green Woodpecker Picus viridis, 13 of the Lesser Spotted Woodpecker Dendrocopos
    minor, 4 of the Black Woodpecker Dryocopus martius. The presence of a pair is not correlated with the plot area. The density of contacts
    and pairs is greater in forests with prevalence of old poplar Populus sp. We calculated an index to analyse the whole Picidae community
    and to compare the different plots. This index has shown a good correlation with the percentage of old poplar trees of a plot. Finally, habitat variables in 15 m radius subplots centered on nest trees and on potentially suitable trees were analyzed. The Black Woodpecker prefers
    high poplar density with a large diameter, preferably dead. On the basis of these results we believe that the riverine forest management
    has to consider the preservation of small natural plots with prevalence of old poplar trees.

  6. I passeriformi dell’ambiente ripariale del lago Trasimeno:risultati di undici anni di inanellamento a sforzo costante

    Muzzatti M., Chiappini M.M., Velatta F., Bonomi M.

    Abstract     Read Article       Download
    16 67

    The riparian Passerines of lake Trasimeno (Umbria, Central Italy): a 11-years study by constant-effort mist-netting. From
    August 1996 to December 2007 at a reedbed site of lake Trasimeno we carried out 562 mist-netting sessions (at least once every ten days).
    Through the years we kept constantly the same numbers and positions of mist-nets. Mist-netting always started at dawn and stopped at
    midday, without using any recorded calling. We trapped 13512 birds belonging to 52 species. The collected data allowed us to investigate: the composition and the ecological parameters of the passerine community and their seasonal variations; trends of the most abundant
    species, calculated taking into account either the whole annual sample or only the breeding population (adult age-class during the breeding season). We found 12 species being dominant at least in one month: Prunella modularis, Cettia cetti, Acrocephalus melanopogon,
    A. schoenobaenus, A. scirpaceus, A. arundinaceus, Phylloscopus collybita, Sylvia atricapilla, Erithacus rubecula, Cyanistes caeruleus,
    Remiz pendulinus, Emberiza schoeniclus. The community parameters showed strong seasonal variations: abundance, biomass values and
    percentage of marshland species were highest from late spring to early autumn, while in the same period diversity and equitability reached
    their minimum. Considering for each species the complete annual sample, only three species out of 18 showed signifcant trends: Panurus biarmicus (decrease), Erithacus rubecula (increase), Emberiza schoeniclus (increase). Taking into account the breeding species, we
    found out signifcant negative trends for Panurus biarmicus, Cettia cetti, Remiz pendulinus; the remaining species (Acrocephalus scirpaceus, A. arundinaceus, Sylvia atricapilla, Parus major, Passer italiae) showed negative but not signifcant variations. The decrease of
    some marshland species might depend (at least in part) on the reedbed loss and degradation.

  7. Relazioni tra una comunità di uccelli e densità di Gattodomestico Felis silvestris catus in un’area urbana siciliana

    Siracusa A.M.

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    18 61

    In an urban area of the Province of Catania the relationships between feral domestic cat Felis silvestris catus and the bird community have been studied. Despite a drastic decline of cat density, signifcant changes in the community structure and abundance of bird
    species were not observed in the same time-interval. Predation by the domestic cat on the bird populations living in urban environments
    may not necessarily have negative effects, differently form what observed in sea islands, owing to the ethological characteristics of the
    predator, environment and the type of management by man. Other human factors, like the conversion or destruction of habitats, including
    areas adjacent to the urban area, network of roads, traffc pollution, may have more intense and subtle effects.

  8. Trends at a roost of Short-toed Eagles Circaetus gallicusover ten years.

    Premuda G.

    Abstract     Read Article       Download
    22 95

    Andamento decennale di un dormitorio di biancone
    Circaetus gallicus. Le osservazioni sono state svolte dal 2000 al
    2009, in una piccola valle situata in provincia di Bologna (Emilia-Romagna), durante sedici visite effettuate nel periodo dal 24
    giugno al 3 agosto. Il dormitorio era composto inizialmente da
    due bianconi, che sono aumentati fno ad un massimo di dodici
    nel 2004 e alla fne del periodo monitorato sono scesi a tre individui, con un minimo di uno nel 2008. Nei dieci anni in totale sono
    stati rilevati 51 individui di biancone, dei quali la maggior parte
    (69%) composta di immaturi. La presenza nell’area di immaturi e di adulti non nidifcanti, entrambi non territoriali, era molto
    probabilmente la causa dell’inusuale concentrazione di individui
    osservati. Escludendo i periodi di migrazione, le osservazioni di
    dormitori di biancone sono molto rare e apparentemente di natura
    occasionale, come suggerito dall’unico altro caso noto, rilevato in
    Israele, dove il raggruppamento è stato attribuito ad una eccezionale abbondanza di cibo (roditori) nell’area.

  9. Data on spring migration of immature Short-toed Eagles Circaetus gallicus through the Central Mediterranean route (Italy, Tunisia) .

    Premuda G., Baghino L., Gustin M., Borioni M.

    Abstract     Read Article       Download
    22 95

    Dati sulla migrazione primaverile degli immaturi di
    Biancone Circaetus gallicus attraverso la rotta del Mediterraneo
    Centrale (Italia, Tunisia). Osservazioni sulla fenologia migratoria
    primaverile di immaturi di Biancone sono state svolte nella primavera 2007 in nove stazioni di osservazione dislocate nell’Italia
    peninsulare (n = 3), in quella insulare (n = 5) e in Tunisia (n = 1).
    Nel complesso, la ricerca ha richiesto n = 231 giornate di campo
    (in media n = 25.7 ± 3.9 SE gg/stazione; estremi: Cap Bon n = 8;
    M.te Conero n = 48) concentrate in larga percentuale (n = 82.3%,
    n = 190) tra il 20 aprile e il 20 maggio (estremi: 9 marzo – 31 maggio), per un totale di n = 2002 ore di osservazione (in media n =
    222.4 ± 39.9 SE ore/stazione; estremi: Cap Bon n = 33; M.te Conero n = 480). Nel complesso, sono stati identifcati n = 112 individui immaturi in transito, di cui n = 57 (50.9%) ad Arenzano, n
    = 28 (25.0%) a Cap Bon, n = 19 (17.0%) sulle Alpi Apuane e n =
    4 (3.6%) sia sul M.te Conero che in Sicilia e isole minori. Le osservazioni di Arenzano e delle Alpi Apuane (con direzioni di volo
    prevalenti: ENE e SE rispettivamente), così come gli scarsi avvistamenti in Sicilia (direzione di volo prevalente: NE), suggeriscono
    che la maggior parte dei bianconi immaturi effettui in primavera
    una migrazione “a circuito” come gli adulti. Il comportamento riscontrato nei bianconi immaturi, in migrazione tardiva rispetto agli
    adulti, è in accordo con quanto noto e con le osservazioni relative allo Stretto di Gibilterra. La mancata corrispondenza delle osservazioni tra Cap Bon e Sicilia suggerisce due possibili ipotesi:
    a) i bianconi immaturi osservati sul capo tunisino non hanno attraversato il mare e hanno estivato in Africa. Questa prima ipotesi è supportata dal rilevamento tramite trasmettitore satellitare
    di due bianconi rimasti in Africa durante il loro secondo anno di
    vita; b) si trattava di soggetti che hanno attraversato il Canale di
    Sicilia e hanno estivato in Sicilia. Questa seconda ipotesi potrebbe giustifcare l’osservazione di immaturi in transito a Marettimo
    in autunno

  10. Prima nidificazione del marangone minore Phalacrocorax pygmaeus nella Riserva Naturale Regionale Ripa Bianca di Jesi (Ancona)

    Gambelli P., Malanga G., Sebastianelli C., Silvi F., Belfiori D.

    Abstract     Read Article       Download
    22 95

    The Regional Nature Reserve “Ripa Bianca” near Jesi (Ancona, Italy), managed by WWF Italia, is characterized by a
    mixed forest on the banks of an artifcial lake. In this site, since
    twenty years there have been the largest colony of Night Herons
    throughout the Marche Region, to which other species of Herons
    (Grey Heron, Little Egret, Little Bittern) have added over years.
    A.R.C.A. performs visual monitoring of the species living in the
    heronry. Particularly noteworthy the observation in Spring 2010
    of Pygmy Cormorant Phalacrocorax pygmaeus nesting. The species was already observed during the Spring of 2008 and 2009, but
    until 2010 nesting was not established. The frst direct observation
    of the nest is dated 05/06/2010 and the frst pullus out of the nest
    was photographed on 20th August 2010. In Italy the Pygmy Cormorant, species listed in Annex 1 of 2009/147/CE Directive, is a
    regular breeding, wintering and migratory species in the northeastern part of the country (Veneto, Friuli Venezia-Giulia, Emilia
    Romagna). Our observation is the frst of the Pygmy Cormorant as
    a nesting species in Central Italy.

  11. Commissione Ornitologica Italiana (COI) - Report 23

    Janni O. e Fracasso G.

    Abstract     Read Article       Download
    47 404
  12. Resoconto Ornitologico Italiano - Anno 2008

    Sighele M., Janni O.

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    47 404
  13. Oltre Avocetta... l’ornitologia italiana su altre riviste

    Sorace A.

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    47 404

    La rubrica segnalerà i lavori ornitologici che riguardano il
    territorio italiano pubblicati su riviste straniere e italiane
    (escluse RIO, Picus, Alula, Uccelli d’Italia). Le segnalazioni saranno accompagnate in genere da un breve commento. Considerando le diffcoltà di visionare le innumerevoli riviste che potrebbero contenere contributi con dati
    ornitologici di interesse per i lettori di Avocetta, la rubrica non ha la pretesa di produrre un elenco esaustivo dei
    lavori pubblicati sul territorio nazionale. Comunque, per
    rendere l’elenco più approfondito, si invitano gli ornitologi italiani a collaborare attivamente inviando segnalazioni
    commentate, in particolare di lavori locali o settoriali, al
    curatore della rubrica o alla redazione di Avocetta.