Avocetta, vol. 26, n. 1, July 2002
The Corncrake (Crex crex) in Friuli-Venezia Giulia (North-eastern Italy): 3-6
GIANLUCA RASSATI 1 & CHRISTOPHER PAUL TOUT 2
1 Via Udine 9, 33028 Tolmezzo (UD), Italy 2 Via Trieste 29, 34013 Duino (TS), Italy
Abstract – The following article is a summary of the current levels of knowledge available for the Corncrake in the region Friuli-Venezia Giulia, especially with regard to studies carried out from the middle of the 1980’s onwards. This rail species has been the subject of continuous study since the end of the 1980’s in certain sample areas of Upper Friuli both through the collection of general data and, from 1993 onwards, breeding censuses carried out at least twice in each nesting season. During the 1995 nesting season a breeding survey was carried out covering the entire territory of the Region. The studies have enabled us to establish that in Friuli-Venezia Giulia the species is a regular migrant and nesting species that is occasionaly present even in the autumn and winter when one occasionally encounters individuals that for various reasons (injuries, handicaps or disease) are unable to migrate. The regional population censussed in 1995 yielded 203 calling males largely located in the central-north part of the region at an altitude between 100m a.s.l. and 1600m a.s.l. (68,8% of the calling males were found between 500m a.s.l.1999 m a.s.l.). In Upper Friuli, for the period 1993-1999, the majority of the calling (5 1 .3%) were located between 200m a.s.l. The bird is almost completely absent below 200m a.s.l. as a result of the high levels of human impact on the environment and the subsequent absence of suitable habitats for the species. The increasing rarity of the species above 11 00m a.s.l. is due to the lack of broad valley bottoms and human settlements with their regularly cut hay meadows. The upper altitudinal limit for the species is determined by the disappearance of grassland habitats which are replaced by krummholz scrub, screes and bare rock. The environment favoured by the species in Friuli-Venezia Giulia seems to consist of relatively humid hay meadows with good vegetational cover which are regularly cut in areas with at most a slight slope. The authors hope that concrete protection measures for the species will be taken with regular monitoring over the years with a view to gathering information on the habitats used by the birds so that appropriate conservation projects can be undertaken.
Age-dependant adult survival in the Cory’s Shearwater Calonectris diomedea: 7-9
J.-L. MOUGIN, Chr. JOUANIN & F. ROUX
Museum national d’Histoire naturelle, Laboratoire de Zoologie (Mammifères et Oiseaux), 55 rue Buffon 75005 Paris, France
Abstract – In the Cory’s Shearwater Calonectris diomedea of Selvagem Grande (30°09’N, 15°52’W), the annual survival rate of the adult is age-dependant. After having remained almost constant during the first breeding years, it begins to decrease shortly after the 15th when the bird has not much passed its 25th year. Such a trend having also been observed in other seabird groups, it is likely to be widespread. The scarcity of the related data published is thus likely to be only a consequence of the length of the studies necessary to get them.
Distribution patterns of snow finches (genus Montifringilla) in the Tibetan Plateau of China: 11-18
QU YAN-HUA – LE FU-MIN* – YIN ZUO-HUA – STEFANO FABRIZIO DE RITIS°
(Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, CHINA. E-mail: leiftm @panda. ioz.ac. cn) (*Correspondence author. Lei Fu-Min) (°Centro Abruzzese di Ricerche Faunistiche, c/o W-WF Abruzzo c.p. 317 65100 Pescara E-mail: email@example.com)
Abstract – We used data from specimen collection records and field expeditions in the Tibetan Plateau and Xinjiang to assess distribution patterns of six Montifringilla species. By plotting specimen localities with latitude, longitude and elevation, we found that six species overlap greatly on the Tibetan plateau, with a limited distributed area at elevations from about 2500m to 5500m, latitudes from about N26o to N38° and longitude from E 751 to EI 151. At 28 of 71 localities, more than one species has been collected. However, in Xinjiang, only four species occur and they have parapatric complementary distributions. The species whose distribution ranges overlap occur in different habitats and develop different ecological and behavioral characteristics. While some breed and roost in rock crevices, others nest in Pikas (Ochotona curzoniae, Ochotona ladacensis, Ochotona alpina, Ochotona daurica) burrows. Those species sharing similar habitats show significant variations in body traits. It seems that the species with similar body traits are less likely to share similar habitats than are species with rather different body traits.
Spring migration of raptors on Conero Promontory: 19-24
MARCO GUSTIN 1, ALBERTO SORACE 2, DANIELE ARDIZZONE 2 & MARCO BORIONI 3
1 Gobbi 8, 42027 Montecchio Emilia (Re) – e-mail.. firstname.lastname@example.org S ettore Conservazione, via Trento 49 – 43100 Parma 2 SROPU, c/o oasi WWF “BoSco di palo “, via Pale Laziale 2 – 00055 Ladispoli – Roma 3 via Monte Vettore 32, 60131 Ancona
Abstract – A survey of raptor migration on the Conero promontory was carried out during spring 1999 (April 20 – May 20), in which the time of passage, and the direction of both in-coming and out-going flights were recorded. Some 2640 migrating raptors were observed, mostly Honey Buzzards (1699 individuals) and Marsh Harriers (503 individuals), altogether representing about 83.4% of total observations. In-coming flight direction was mostly WSW and WNW, while the direction of out-going flights was mainly ENE and ESE. Significantly more individuals were observed passing in the afternoon (15-1800). In addition, the present study, reveals an increase in the number of raptors observed (about 40% more) migrating over the study site compared to a similar survey carried out in spring 1994. The number of raptors observed in the present study being second only to the number of raptors recently observed migrating over the Straits of Messina. Together, our results confirm the importance of the Conero promontory as a site for raptor spring migration.
Nesting and Feeding Habits of the European Bee-eater (Merops apiaster L.) in a Colony next to a Beekeeping Site: 25-31
BRUNO MASSA & MARIA CONCETTA RIZZO
Stazione di Inanellamento, c/o Sezione Entomologia, Acarologia e Zoologia, Dipartimento SENFIMIZO, viale delle Scienze 13, 90128 Palermo, Italy. E-mail: email@example.com
Abstract – Authors carried out a study on a population of bee-caters colonising a former sand quarry next to a beekeeping site. Data were collected to estimate population size, evaluate microclimate differences inside and outside nest tunnels, calculate bill length and weight variation in relation to nest excavation and nest attendance by bee-eaters, and to analyse their feeding habits, in particular in relation to bee availability. Population size was estimated as much as 100-110 pairs. Bill length resulted to decrease during the nest excavation, growing again after one month. Weight on the contrary was increasing during egg laying and brooding, and decreasing during nestlings’ attendance. Temperature outside nests resulted on average lower than inside the nest tunnel, which in turn resulted much more constant. Bee-eaters are specialized in hymenopterans predation, and considered in some countries a pest for beekeeping. The analysis of the relationships between availability of bees and bees preyed upon by be te . the study area consented to consider bee predation incidence actually acceptable to the bee colony for future survival.
Note sulla biologia riproduttiva del Cannareccione Acrocephalus arundinaceus in zone umide dell’Italia Centrale: 33-39
Via S. Alessandro, 57, 56019 Vecchiano – Pisa
Abstract – During nine years, a study was carried out on the nesting population of Acrocephalus arundinaceus in a large marsh of fresh water and in the small artificial wetland of Central Italy. Data about location of nest and main reproductive parameters were collected with the main purpose of analysing Great Reed Warbler habitat relationships in an attemp to clearify the reasons for numerical reduction of the species from 1992 on. Nest is averagely hanged up in five stems, 91 em from water height and 78 em far from open waters. Under the nest, water is averagely deep 51 em and reed density is of 497 stems/mq For anchorage, 238 em stems high are used each of which is 0,56 em diameter. Eggs are lightly smaller than other italian and european ones. Similarly, compared with literature, the average of a complete clutch – 4,39 eggs – is inferior of 78%. Informations confirmed regular accomplishment of two broods. First brood between april 29 th and june 6 th, second one between june 10th and july 28th, with various episodes of sostitutive first brood. Hatch rate was 77,8%; 90,2% of nestlings have left nest (at least 2,78 each nest are youngs); the total reproductive outcome has thus resulted of 70,2%. 25,7% of builted nests have been plundered or abandoned or parasited by Cuculus canorus. The Great Reed Warbler for reproduction uses different types of reeds and it doesn’t seem to be influenced by Abstract – During nine years, a study was carried out on the nesting population of Acrocephalus arundinaceus in a large marsh of fresh water and in the small artificial wetland of Central Italy. Data about location of nest and main reproductive parameters were collected with the main purpose of analysing Great Reed Warbler habitat relationships in an attemp to clearify the reasons for numerical reduction of the species from 1992 on. Nest is averagely hanged up in five stems, 91 em from water height and 78 em far from open waters. Under the nest, water is averagely deep 51 em and reed density is of 497 stems/mq For anchorage, 238 em stems high are used each of which is 0,56 em diameter. Eggs are lightly smaller than other italian and european ones. Similarly, compared with literature, the average of a complete clutch – 4,39 eggs – is inferior of 78%. Informations confirmed regular accomplishment of two broods. First brood between april 29 th and june 6 th, second one between june 10th and july 28th, with various episodes of sostitutive first brood. Hatch rate was 77,8%; 90,2% of nestlings have left nest (at least 2,78 each nest are youngs); the total reproductive outcome has thus resulted of 70,2%. 25,7% of builted nests have been plundered or abandoned or parasited by Cuculus canorus. The Great Reed Warbler for reproduction uses different types of reeds and it doesn’t seem to be influenced by any specific parameter. The recent increase of water level in Massaciuccoli – with the consequent delayed growth of reeds seems to have a negative influence on the territorial occupation phase for what concerns males.
Water-crossing tendency of juvenile Honey Buzzards Pernis apivorus during migration: 41-43
NICOLANTONIO AGOSTINI 1, CHARLES COLEIR0 2, FERDINANDO CORBI 3, GIUSEPPE DI LIET0 3, FABIO PINOS 3 & MICHELE PANUCC10 4
1 Via Carlo Alberto n. 4, 89046 Marina di Gioiosa Jonica (RC), Italy. 2 St. Michael Flat 2, Paris Street, Zebbug, Malta. 3 Gruppo Pontino Ricerche Ornitologiche, Via Ticino n. 12, 04100 Latina, Italy 4 Via Mario Fioretti n. 18, 00152 Roma, Italy.
Abstract – The autumn migration of juvenile Honey Buzzards was studied from 15 to 29 September 2000 at three sites of the central Mediterranean: the Circeo promontory (central Italy) and the islands of Marettimo (western Sicily) and Malta. The aim of this study was to test the hypothesis that juvenile Honey Buzzards leaving the Italian peninsula from the Circeo promontory, reach Tunisia via the island of Marettimo. At the Circeo promontory a total of 500 individuals was counted with the peak on 21 and 22 September. Juvenile buzzards showed a strong tendency to undertake the sea crossing flying south apparently towards western Sicily via the island of Ponza. 13 birds were seen flying back inland. On average flocks contained 4.8 birds and only one, observed on 21 September, contained more than 20 individuals (87). Over the island of Malta 564 Honey Buzzards were counted with a maximum of 279 on 23 September. There was a notable correspondence between data recorded in these two sites, both concerning the variations of the migratory flow and the size of flocks. Over Marettimo, a total of 45 buzzards were seen in the whole period. These results do not agree with the hypothesis tested in this study; on the contrary they seem to suggest that birds avoid the crossing of the Tyrrhenian Sea deviating east towards the Italian peninsula and passing over Malta about two days later.
Nest site and Breeding Biology of the red-footed falcon (Falco vespertinus) in northern Italy: 45-47
STEFANO SPONZA 1, DAVIDE LICHER1 2, LAURA GRASS1 3
1 Dipartimento di Biologia – Università degli Studi di Trieste, Via L. Giorgieri, 9 1-34127 Trieste, Italy. 2 lstituto Nazionale per la Fauna Selvatica ‘A Ghigi “, Via Ca’ Fornacetta, 9 –I-40064 Ozzano Emilia (BO), Italy. 3 Riserva Naturale Regionale “Foce dell’Isonzo ” – 1-34070 Staranzano (GO), Italy.
Riassunto – Una popolazione di Falco cuculo di sette coppie nel 1997 e di quattro nel 1998 si è stabilita nella pianura padana, in provincia di Parma. Le coppie hanno utilizzato nidi di Cornacchia grigia, posti su alberi di 16-20 m d’altezza e con una copertura fogliare perlomeno di 5 m di spessore. In entrambe le stagioni riproduttive è stata riscontrata un’elevata sincronia tra le diverse coppie, malgrado l’assenza di vere e proprie colonie, caratteristiche nell’areale riproduttivo tipico della specie.
Book reviews: 49-51
Errata Corrige: 52
Avocetta, vol. 26, n. 2, September 2002
Italian breeding avifauna distribution: first bulletin of the MITO2000 program: 59-115
L. Fornasari 1, E. de Carli 2, S. Brambilla 2, L. Buvoli 2, E. Maritan 2 & T. Mingozzi 3
1 Dip. Scienze dell’Ambiente e del Terrirorio, Univ.di Milano Bicocca, Piazza della Scienza 1 – 20126 Milano 2 Fauna Viva, via Biringhello 114 – 20126 Milano 3 Dip. Ecologia, Univ. della Calabria – 87036 Rende (CS)
Abstract – An Italian Breeding Bird Monitoring Program started in the breeding season of 2000, organised by the CISO (Centro Italiano Studi Ornitologici), the University of Milano Bicocca, the University of Calabria and the Association FaunaViva, with financial support from the Italian Ministry of Environment. The program is called MITO2000, from the acronym of Monitoraggio ITaliano Ornitologico (Italian Ornithological Monitoring). Monitoring program organisation included the creation of a network of 25 local co-ordinators, established on a regional and sub-regional basis.
A simplified version of 10 minute point counts was chosen for the bird survey. Birds heard and seen were recorded in two belts, inside and outside a 100 m radius circle. Environmental data were recorded inside the 100 m radius circle by using CORINE categories; 5% intervals (5% – 10% – 15% … 95% – 100%) were used to record coverage. Third level categories were predominantly used, but we chose fourth level ones, if already existing, when they were considered more important in determining birds distribution and abundance (for instance, wood composition). In all, we used five first level, 15 second level, 45 third level and 18 fourth level categories.
Two surveys were planned: a) a random survey, based on randomly selected point counts distributed throughout the country according to the 50×50 km UTM grid; b) a selected point counts survey, performed in Special Protection Areas (SPA) and other important bird areas, called for this purpose Important Ornithological Areas (IOA).
For the random survey point counts were performed in each of the Italian 181 50×50 km units, defined according to UTM grid. In each 50×50 km unit, four 10×10 km secondary units (out of 25) were selected randomly; fewer when the larger unit was not totally occupied by Italian land. A total of 542 10×10 km units was therefore identified. 15 point counts were conducted for each 10×10 km secondary unit; the location of this point counts was also selected randomly, by extracting 15 (out of 100) 1×1 km squares. Surveyors were asked to perform the point count as near as possible to the 1×1 square centre. A substitution procedure was used when the square selected originally proved unreachable.
In addiction, at least 15 more point counts were required in each 50×50 km unit, either in SPA or, in the units lacking SPA, in IOA. The number of point counts performed in each SPA/IOA was proportional to the area, ranging between 4 and 60. Because of logistical problems, SPA on small Mediterranean Islands were excluded a priori from the survey, as well as SPA that were smaller than 2 sqkm.
In order to convert observation data into breeding pair numbers, surveyors were asked to record both observed bird numbers and activity. The estimated number of breeding pairs were calculated according to predetermined conventions: for instance, a singing male or family party were regarded as a breeding pair, while a single individual observed in a non-reproductive activity was regarded as 0.5 breeding pair. An expressly created software was used to store data, to automatically calculate breeding pairs and to send data to General Co-ordination Group.
A total of 222 surveyors took part in the surveys, between April and July 2000, performing some 7710 point counts: 6019 in 448 10×10 km UTM units (83% of the available units), included in 165 50×50 km UTM units (91% of available units); the remaining 1691 point counts were performed in 144 SPA and IOA located through the whole country. Significant coverage gaps were due both to the shortage of local surveyors and to some co-ordinators’ poor efficiency, as in Marche region (3 10×10 unit investigated out of 17 expected), in Piedmont (15 out of 30), in Sicily (32 out of 50) and in Sardinia (24 out of 44).
Overall, 266 bird species were observed; about 230 of them were regarded as breeders. Estimated breeding pairs were 145,488. Among the breeding species, five are included in the IUCN Red List of Threatened Species, while 69 are in the Annex I to Wild Birds Directive 79/409 and 74 in the Italian Red List (at Vulnerable, Endangered or Critically endangered levels). Due to some overlapping of the lists, those conservation concern species are overall 102. Among them, 16 were recorded in at least 20 UTM 50×50 km units, considering data from both surveys. Each of these species showed greater abundance in SPA/IOAs than in random areas.
In the random survey alone, 224 bird species were recorded, of which 20 of them have been regarded by local coordination groups as early migrants or summering species, and at least one (White-headed Duck Oxyura leucocephala) as a probable escape. In the second survey, some 100 SPAs and 44 IOAs were visited. A number of 232 species were observed in 1265 point counts performed in SPAs. The number of recorded species is very similar to the number of species recorded within the random survey, even if the number of point counts in the random survey was five times greater. Overall, 31 species were observed only in SPAs (not in random areas); at least 13 of them are special conservation concern species. However, 23 species were observed only in the random program (not in SPAs). In 426 point counts performed in IOAs, 195 species were recorded. Some 7 of them were recorded only in IOAs, and at least one is a special conservation concern species (Audouin’s Gull Larus audouinii).
We considered “common species” as those recorded in at least 20% of the 50×50 km units visited. Overall, we recorded 94 common species; 67 are Passeriformes, while 27 belong to 13 other orders, the most numerous ones being Accipitriformes and Columbiformes with 5 species each. Of the 13 most common species, 12 were Passerines; the commonest was the Goldfinch. For several species, a semi-quantitative map was produced, using the 50×50 km UTM grid, and a detailed text was also written. We used abundance (pairs/10 point counts) as representation unit. An altitudinal distribution bar graph (250 m belts) was also created for each species. Some examples are given in a following section.
According to the subdivision of Italy into bio-geographical regions, it is possible to identify general patterns of species distribution. Overall, six areas were identified: Central Alpine sub-region, Northern Alpine sub-region, Continental Region, Peninsular Mediterranean sub-region, Sicilian Mediterranean sub-region, Sardinian Mediterranean sub-region. Statistical analysis of environmental data for the reported species were carried out according to bio-geographical classes; different climatic conditions and their possible influence on the bird habitats were also taken into consideration. The application of multivariate statistics procedures allowed the identification of significant determinant habitats of the abundance of each species, always considering bio-geographical subdivision.
Our survey’s results are generally in accordance with the known composition of Italian avifauna. The total of 266 species is wholly comparable to the number of 265 breeding species recorded in the Atlas drawn in the 80es. As expected in the survey outlines, the adopted methodology was appropriate for semi-quantitative evaluations on Passeriformes species and ecologically similar orders (such as Apodiformes and Columbiformes). However, non-randomised survey data show representative results as regards the distribution and abundance of relevant number of conservation concern species, and non exhaustive information about a very wide species number.
Further analyses of the data set are possible. In particular, a comparison with the distribution reported by the previous National Atlas is suggested, as well as the design of population indices estimating the trends by repeating the monitoring program.
Riassunto – Nella stagione riproduttiva dell’anno 2000 ha preso l’avvio, con il sostegno finanziario del Ministero dell’Ambiente, il programma di monitoraggio dell’avifauna nidificante denominato MITO2000 (Monitoraggio Italiano Ornitologico). Il programma è stato organizzato su base regionale o sub-regionale, attraverso una rete di coordinatori individuati tra i gruppi di omitologi organizzati a livello locale. Lo scopo perseguito è di ottenere su base annuale carte di distribuzione semi-quantitative per tutto il territorio italiano, così da disporre, a partire dal secondo anno, di informazioni relative agli andamenti delle popolazioni nidificanti, differenziate per area geografica. Questa iniziativa, coordinata a livello italiano dal Centro Italiano Studi Ornitologici, si inserisce nel programma Euromonitoring avviato dallo European Bird Census Council su scala continentale.
La metodologia prescelta è una versione semplificata dei punti di ascolto di dieci minuti di durata, associata al rilievo ambientale secondo le categorie CORINE di quarto livello. Il campionamento è stato eseguito in base a: a) un programma randomizzato, organizzato sulla griglia UTM di 10 km di lato, con un numero di circa 15 punti di ascolto per ognuna delle unità selezionate; b) un programma su aree prefissate, condotto in Zone a Protezione Speciale (ZPS) o altre aree di interesse denominate Zone di Interesse Ornitologico (ZIO). Hanno preso parte al programma 222 rilevatori, che hanno effettuato un totale di 77 10 punti d’ascolto. Sono state complessivamente contattate 266 specie di uccelli, di cui circa 230 nidificanti. Il totale di “coppie convenzionali” stimate è stato di 145.488; 75.836 le indicazioni di presenza complessive.
Considerando l’insieme dei dati raccolti in base ai due programmi di rilevamento, sono state definite “comuni” tutte le specie osservate in almeno il 20% delle maglie UTM 50×50 km visitate. Si tratta di 94 specie, di cui 67 Passeriformi e 27 ripartite in altri 13 ordini. Nel gruppo di 13 specie rilevato in oltre l’80% delle maglie UTM 50×50 km visitate sono compresi 12 Passeriformi e 1 Apodiforme. La specie con distribuzione più ampia risulta essere il Cardellino Carduelis carduelis.
Tra le specie contattate nel corso del programma, 5 sono incluse nella IUCN Red List, 74 nell’Allegato 1 alla Direttiva Europea 79/409 e 70 nella Lista rossa degli uccelli nidificanti in Italia, per un totale di 102 specie definite “prioritarie”. Ciascuna delle 16 specie prioritarie rilevate in almeno 20 maglie UTM 50×50 km ha mostrato abbondanze maggiori nei campionamenti effettuati all’interno delle ZPS e delle ZIO rispet~ to ai punti dei programma randomizzato.
I dati raccolti, trasmessi ad un coordinamento centrale presso l’Università degli Studi di Milano Bicocca, sono stati riuniti in un unico data-base costituito presso il Servizio Conservazione Natura del Ministero dell’Ambiente. Per le specie rilevate in tre o più maglie sono state prodotte elaborazioni di dati ambientali, distribuzioni altitudinali per fasce di 250 m di ampiezza e cartografie di tipo semi-quantitativo sulla base delle maglie UTM di 50 km di lato.
In questa sede sono presentati la metodologia d’indagine, i risultati generali del primo anno di rilevamento e le schede complete relative a 15 delle specie a distribuzione più ampia.
Commissione Ornitologica Italiana (COI) / Italian Rarities Committee – Report n. 15: 117-121
a cura di P. Brichetti*, E. Arcamone*, D. Occhiato* & COI* * Centro Italiano Studi Ornitologici (CISO)
Uccelli acquatici nidificanti: 2000: 123-129
a cura di L. Serra* & P. Brichetti** * I.N.F.S., Via Ca’ Fornacetta 9, 40064 Ozzano Emilia BO (e-mail: firstname.lastname@example.org); ** C.I.S.O., Via V. Veneto 30, 25029 Verolavecchia BS (e-mail: email@example.com)
Breeding waterbird in Italy: 2000. Brreding population numbers of 23 waterbird species with a localised distribution in Italy are given.