Avocetta, vol. 29, n. 1, 2005
Caratteristiche del sito di nidificazione, densità e biologia riproduttiva dell’averla piccola Lanius collurioin Italia centrale : 5-11 GASPARE GUERRIERI, AMALIA CASTALDI
GAROL (Gruppo Attività Ricerche Ornitologiche del Litorale), Via Villabassa 45, I-00124 Roma (firstname.lastname@example.org) Abstract – Nest-site features, density and breeding biology of the red-backed shrike Lanius collurio in Central Italy. We studied the reproductive biology of red-backed shrike Lanius collurio in two mediterranean and temperate areas of Central Italy from 1992 to1998. Dates of settlement, nest-building and egg-laying did not differ between the study areas. Mediterranean area had a lower density of breeding pairs (0.49 pairs/10 ha) than the temperate area (1.66 pairs/10 ha), and hosted more unmated males. Nests height was higher in the mediterranean area, while the average clutch size was significantly lower. The number of sterile eggs and the average number of fledglings did not differ between areas, while nest loss due to predation was significantly higher in the mediterranean area. Moreover, unsuccessful pairs abandoned their territory more frequently in mediterranean area and number of non-breeding pairs was higher compared to temperate area. Higher predation rates might be the main reason for the lower breeding performance of red-backed shrikes in mediterranean areas.
Sex and age ratios of marsh harriers Circus aeruginosus wintering in central-southern Italy: 13-17 MICHELE PANUCCIO, BRUNO D’AMICIS, EMANUELA CANALE, AMELIA ROCCELLA
MEDRAPTORS (Mediterranean Raptor Migration Network), via Mario Fioretti 18, I-00152 Roma, Italy (email@example.com) Abstract – In this study we analyse the age and sex ratios of marsh harriers wintering in central Italy and Sicily. Among adults, most individuals were females (88%), whereas males accounted for only 12% of the observations. There was no difference in the proportion of juveniles and adults. The remarkable difference in numbers of males and females seems to support the hypothesis that, at least among adults crossing the central Mediterranean, males show a stronger tendency to migrate over longer distances. Among the proposed hypotheses explaining intraspecific differences in avian migration patterns, the Bergmann’s rule, which predicts that larger individuals (i.e. females in this case) are better adapted to survive in colder climates, appears to be in agreement with our results, whereas other hypotheses based on social dominance are less supported by our data, as suggested by the similar proportion of juveniles and adults.
Distribuzione e consistenza delle popolazioni nidificanti di forapaglie comune Acrocephalus schoenobaenusin Italia : 19-26 PIERANDREA BRICHETTI, NUNZIO GRATTINI, FAUSTA LUI3
1CISO Via V. Veneto 30, I-25029 Verolavecchia (BS) (firstname.lastname@example.org); 2Via P. Gobetti 29, I-46020 Pegognaga (MN); 3Via Bardelle 52 , I-46027 San Benedetto Po (MN)
Abstract – Breeding distribution and abundance of sedge warbler Acrocephalus schoenobaenus in Italy. In this review, we critically examine the present status of the sedge warbler Acrocephalus schoenobaenus in Italy, providing new information on the population abundance. The breeding area of the species is at present discontinuous and unstable, and is limited to the central-eastern Po-Valley and Tuscany. Both the historical and the present distributions are based either on generic data or unsafe assumptions, probably referring to late migrators presence. The Italian breeding population is estimated at 15-25 pairs in the years 1994-2004, with a noticeable decrease compared to the 30-100 pairs in the ‘80s. The Mincio Valleys (Lombardy) is the only permanently used site (4 breeding pairs), while no further evidence of breeding has been recorded in the Busatello wetlands since 1997. The local habitat loss is likely to be one of the main factors of population decrease, although the north-western European population fluctuate in relation to the draughts in the wintering quarters of Western Africa.
Autumn migration strategies of honey buzzards, black kites, marsh and Montagu’s harriers over land and over water in the Central Mediterranean : 27-32 MICHELE PANUCCIO, NICOLANTONIO AGOSTINI, UGO MELLONE
MEDRAPTORS (Mediterranean Raptor Migration Network), via Mario Fioretti 18, I-00152 Roma, Italy (email@example.com)
Abstract – Observations on the autumn migration of honey buzzards Pernis apivorus, black kites Milvus migrans, marsh Circus aeruginosus and Montagu’s harriers C. pygargus were made between 24 August and 10 September 2004 at the western slope of the Calabrian Apennines (Straits of Messina) and over Panarea (Lipari Islands). The aim was to compare the post-reproductive migration patterns of these raptors over land and over water along two parallel flight paths, as well as to verify the existence of a migratory movement of the black kite across the southern Tyrrhenian Sea in this period. A total of 7738 raptors were counted at both sites, most of which were honey buzzards (73.7%), black kites (9.1%) and marsh harriers (16.0%). Only 838 birds were seen over Panarea, most of which were marsh harriers (75.3%). No black kites were observed on Panarea. Thus, while marsh harriers migrated on a broad front, honey buzzards and black kites migrated over land and approached the Straits of Messina en route towards the Channel of Sicily, between western Sicily and Cap Bon in north Africa. This study shows no indication of a black kite migration across the southern Tyrrhenian Sea. Finally, our results confirm that, unlike spring migration, few Montagu’s harriers cross the Central Mediterranean during post-reproductive movements.
A new case of interspecific brood parasitism in the common moorhen Gallinula chloropus : 33-36 ALIN DAVID, CASINA VASS, IOAN COROIU
Riassunto – Un nuovo caso di parassitismo interspecifico di cova nella gallinella d’acqua Gallinula chloropus. Con questo lavoro segnaliamo il quarto caso di parassitismo interspecifico di cova nella gallinella d’acqua, rilevato nello stagno di Campenesti (Cluj County, Romania) nel 2004, in un nido di tarabusino Ixobrychus minutus. L’osservazione costituisce anche il secondo caso in cui la specie parassitata appartiene al genere Ixobrychus.
La comunità ornitica in un’area agricola lombarda dal 1971 al 1986 : 36-39 FLAVIO FERLINI
Abstract – The avian community of an agricultural area of Lom – bardy (N Italy) between 1971 and 1986. I collected data on the occurrence of bird species in an agricultural area of Lombardy (45° – 6’ N, 9° – 6’ E), between 1971 and 1986. Overall, 107 species were recorded. The yearly species richness and the number of species of conservation concern (SPEC) did not significantly declined during the study period. However, the number of breeding non-passerines and insectivorous species decreased significantly over the study period. These results confirm the negative population trends of some species related to agricultural habitats observed elsewhere in Europe.
Popolazioni di uccelli acquatici nidificanti in Italia – Resoconto 2001: 41-44 A cura di Lorenzo Serra & Pierandrea Brichetti
Nuovi avvistamenti: 44-50 a cura di Emiliano Arcamone
Ornitologia italiana su riviste straniere: 52-54 A cura di Alberto Sorace
Avocetta, vol. 29, n. 2, 2005
Spatial and seasonal variation in nocturnal autumn and spring migration patterns in the western Mediterranean area: a moon-watching survey: 63-73 Barbara Trösch, Roberto Lardelli, Felix Liechti, Dieter Peter & Bruno Bruderer
Schweizerische Vogelwarte, CH-6204 Sempach, Switzerland (firstname.lastname@example.org)
Abstract – Nocturnal autumn and spring migration patterns around the western half of the Mediterranean sea were investigated simultaneously in different countries by means of an improved moon-watching method. This report is based on over 6000 individual observations reported by up to 160 volunteer observers from 45-62 sites (depending on season and weather), and the data were collected and analysed by the Swiss Ornithological Institute. Intensities and directions of migration are presented for the full-moon periods of autumn 1996, 1998 and spring 1997. In autumn, westerly directions of migration prevailed in northern Italy , shifting towards SW along the French Mediterranean coast and to SW-SSW on the Iberian peninsula, with deviations and scattered directions near relevant topographical features. In autumn, migration intensities were high in northern Italy , slightly lower along the Mediterranean coast and reached again high values across the Iberian peninsula, while low intensities occurred in central Italy and on the islands. In spring, directions of migration were around NE-NNE in all areas, and the intensities were more evenly distributed over the observation areas than in autumn, suggesting that spring migration occurs on a broader front than autumn migration. Relatively strong NE-NNE migration in northern Italy suggests arrivals from the sea and direct crossing of the Alps . Intense spring movements across the Mediterranean and Adriatic seaare indicated by intense migration across the central part of the Italian peninsula.
Diversità e struttura dell’avifauna in una successione post incendio di bosco meso-mediterraneo: 75-84 Enrico Bellia
Dipartimento di Biologia Animale, Via Archirafi 18, I- 90123 Palermo (email@example.com)
Abstract – Diversity and turn-over of a bird community along a secondary post-fire succession of a Mediterranean wood. I analysed the species richness, the turn-over and the structure of the bird communities along a secondary post-fire succession (Erico-Quercion ilicis) in the Madonie Regional Park ( Sicily ). During the springs 2002 and 2003, I made 475 random point counts in 6 sampling areas burned between 1993 and 2001, and in 4 control areas not burned since 25 or 50 years. Overall, 33 bird species were recorded in the secondary succession. Species richness was positively related to the time elapsed from fire, according to a logarithmic curve that reached a plateau 25-30 years after fire. The turn-over of species decreased during the succession, even if the relationship was only marginally significant. In the first stages of post-fire succession the turn-over reflected the recolonisation by species of shrubby vegetation. Bird communities in each post-fire stage form an ordered nested subset of the whole forest community. The investigated bird community showed a relatively high resistance and resilience to fire perturbation and was able to recover completely in 25 years after fire.
Escherichia coli infection in house sparrows: are there implications for sexual selection?: 85-89 Marnie Archbold, Aldo Poiani & Glenn Browning
Riassunto – Prevalenza di Escherichia coli nella passera europea e potenziali implicazioni per la selezione sessuale. In questo studio si riporta la prevalenza di infezioni cloacali da E. coli nella passera europea. Su un campione di 30 individui (17 maschi, 13 femmine), il 33.3% è risultato infettato da E. coli. Non è stata riscontrata una significativa differenza nella prevalenza di infezione di maschi (41.1%) e femmine (23%), nonostante le cospicue differenze osservate. Inoltre, le femmine con la placca incubatrice sviluppata mostravano una tendenza verso una maggiore prevalenza di infezione (37.5%, 3/8) rispetto a femmine senza placca (0%, 0/5), e i maschi infetti tendevano a mostrare un ‘bavaglino’ di dimensioni ridotte. Le tendenze osservate in questo studio meritano ulteriori approfondimenti, in quanto coerenti con la ‘Contagion Indicator hypothesis’.
Artificial lights and mortality of Cory’s shearwater Calonectris diomedea on a Mediterranean island: 89-91 Nicola Baccetti, Paolo Sposimo & Francesca Giannini
Riassunto – Luci artificiali e mortalità della berta maggiore Calonectris diomedea su un’isola mediterranea. Si riporta il rinvenimento di giovani berte maggiori, appena involate dal nido, che erano state attratte da faretti recentemente attivati all’interno del porticciolo dell’isola toscana di Pianosa. Il fenomeno, che in assenza di interventi avrebbe potuto portare alla perdita almeno del 12% del totale di giovani involati nel 2004, è ben noto per la sua gravità al di fuori del Mediterraneo. Si sono sperimentate con apparente successo forme di illuminazione alternativa.
Commissione Ornitologica Italiana (COI) – Report 19: 93-97 A cura di Pierandrea Brichetti & Daniele Occhiato
Resoconto Ornitologico Italiano – Anno 2004: 98-102 a cura di Ugo Mellone. Maurizio Sighele & Emiliano Arcamone
Ornitologia italiana su riviste straniere: 104-105 A cura di Alberto Sorace
News: 107 a cura della Redazione