Avocetta, vol. 27, n. 1, May 2003

Proceedings of the I Italian Congress on diurnal and nocturnal Raptors
  Preganziol (NTV) 9-10 March 2002

Avocetta, vol. 27, Numero speciale, September 2003

Proceedings of the XII Italian Ornithological Congress
  Ercolano (NA) 23-27 September 2003

Avocetta, vol. 27, n. 2, September 2003

Abstracts

Are garters attractive and why? A case study in the moorhen (Gallinula chloropus): 163-165.
Stefano Fenoglio & Beatrice Guasco

Università del Piemonte Orientale, Via Cavour 84 , I-15100 Alessandria

Riassunto - Le giarrettiere o garters sono un interessante elemento nella morfologia della Gallinella d’acqua: si tratta di anelli rosso-arancio posti sopra la giuntura tibiale, presenti negli adulti di entrambi i sessi. Considerando il fatto che sono segnali costosi, derivanti dalla deposizione di carotenoidi, e che è evidente una loro notevole variazione durante l’anno (sia nelle dimensioni sia nella colorazione) abbiamo ipotizzato che tali elementi debbano essersi evoluti sotto la spinta di precise pressioni evolutive. Scopo del nostro lavoro è stato testare l’importanza delle giarrettiere nella comunicazione parentale. In condizioni sperimentali, abbiamo evidenziato che i pulli di questa specie mostrano una significativa preferenza nel seguire zimbelli dotati di anelli rossi sulle zampe. Abbiamo quindi discusso questo risultato, sottolineando la potenziale importanza di segnali parentali in specie precoci e caratteristiche di ambienti con una bassa visibilità, come canneti e tratti boscati perifluviali.
Abstract - Garters are important elements in moorhen morphology: they are orange-red bands above tibial joint, whose size and colour intensity vary throughout the year. We tested the hypothesis that garters are important in parental communication. In open field experiments we found that moorhen chicks showed evident preferences for decoys with garters, and we discuss these findings in the light of some aspects of moorhen behavioural ecology

Revisione delle segnalazioni italiane di Falco peregrinus pelegrinoides Temminck, 1829: 167-171
Bruno Massa & Pierandrea Brichetti

(1) Stazione Inanellamento c/o Dip. SENFIMIZO, V.le delle Sceinze 13 - 90128 Palermo, e-mail: zoolappl@unipa.it
(2) Cenrto Italiano Studi Ornitologici, e-mail: pbrichetti@alice.it

Riassunto - Gli autori hanno esaminato gli esemplari italiani ritenuti appartenere al taxon Falco peregrinus pelegrinoides, conservati in musei e collezioni, giungendo alla conclusione che un solo esemplare (un adulto catturato a Taranto il 22.IV.1900) ha caratteri diagnostici che inequivocabilmente conducono a questa identificazione; gli altri esemplari (tutti juv.) sono invece riferibili a forme più o meno rossicce di Falco peregrinus brookei, la cui identificazione è spesso problematica.
Abstract - Authors examined italian specimens considered as belonging to taxon Falco peregrinus pelegrinoides, preserved in Museums and collections, concluding that only one specimen (adult captured at Taranto on 22 April 1900) shows typical characters which consent to identify it as Falco peregrinus pelegrinoides; instead, other specimens (all juv.) are referable to more or less rufous plumages of Falco peregrinus brookei, identification of which is often problematic.

Influenza di fattori ambientali sulla predazione e alimentazione al nido dell’Averla piccola, Lanius collurio, nell’Italia centrale: 173-170
Gaspare Guerrieri & Amalia Castaldi

G.A.R.O.L. (Gruppo Attività Ricerche Ornitologiche del Litorale) via Villabassa 45  00124  Roma e-mail: g.guerrieri@mclink.it

Riassunto - E’ stata studiata per 5 anni (1994-1998) la predazione e l’alimentazione al nido dell’Averla piccola, Lanius collurio, in due aree campione dell’Italia centrale. In base ai riscontri, il numero medio di attacchi / ora non sembrerebbe diverso tra i sessi, ma esclusivamente condizionato dalle caratteristiche ambientali. Il successo nella predazione, costante nelle due aree (70 %), invece, è sempre superiore nella femmina (+ 10 %). Nelle prime ore del mattino, l’efficacia della predazione è più bassa che nelle altre ore del giorno. La predazione in volo, tecnica preferita dal maschio, viene utilizzata maggiormente in area temperata. Durante la cova, il maschio contribuisce all’alimentazione della femmina per circa il 70-80 %. Nelle ore centrali del giorno, la femmina abbandona spesso il nido e tende ad alimentarsi da sola. Durante l’allevamento, il numero medio di imbeccate / ora è simile nelle due aree, ma i ritmi di alimentazione risultano diversi. Nel mese di giugno, gli Ortotteri sono il taxon maggiormente predato per alimentare i pulli (40 %). I vertebrati sono catturati raramente (0.26 %) e le prede non vengono impalate.
Abstract - The environmental influence on the plundering and nest feeding of the Red-backed Shrike, Lanius collurio, as been studied in two sample areas of Central Italy for five years (1994-1998). According to the results, the average number of attacks per hour does not seem to be different between males and females, but conditioned only by environmental characteristics. However, plundering success, constant in the two areas (70 %), is always higher in females (+ 10 %). In the early morning plundering efficacy is lower than during the rest of the day. Flight plundering, a tecnique preferred by males, is used largely in temperate areas. During brooding the male contributes to the female feeding for about 70-80 %. In the central hours of the day the female often leaves the nest and tends to eat on her own. During breeding, the average number of beakfuls per hour is similar in the two areas, but feeding rythms seem to be different. In June, Orthoptera are the most predated taxon to feed the young birds (40 %).  Vertebrates are rarely captured (0.26 %) and plunders are not impaled. 

Sex differences in body measurements of Rock Partridges Alectoris graeca saxatilis inhabiting the southern French Alps: 181-186
Ariane Bernard-Laurent,(1), Eve-Marie Corda (2) & Dominique Soyez (2)

(1) Office National de la Chasse et de la Faune Sauvage (ONCFS), Direction des Etudes et de la Recherche,CADAM, Préfecture Est, F-06286 Nice cedex 3, France Tel : 33 (0) 4 93 72 20 87, Fax : (0) 4 93 72 20 66, E-mail: a.bernard@oncfs.gouv.fr
(2) ONCFS, Direction des Etudes et de la Recherche, St Benoist, F-78610 Auffargis, France

Abstract - The sexual dimorphism in size was investigated in a galliform species with monomorphic plumage, the Rock Partridge (Alectoris graeca saxatilis), by measuring five morphological variables on 90 males and 90 females collected in the southern French Alps during autumn hunting seasons 1985 to 1995. The sex of all birds was determined by internal examination of the gonads. For all variables, males were significantly heavier and larger than females, whatever the age class (adults vs. juveniles).
We also sought external criteria that would reliably separate male and female juveniles before the hunting season, using discriminant analysis of morphological measurements taken at weekly intervals on 106 hand-reared birds of known ages. Juveniles could be correctly sexed 90-100 % of the time at 8, 12 and 18 weeks of age by discriminant models containing 2-3 variables, i.e. body mass and tarsus length together or in combination with wing length or circumference of the head at the level of the eyes. Because hand-reared birds were a little heavier and larger than wild ones, discriminant equations developed for determining the sex of juveniles could not be applied to wild individuals. Sex criteria derived from measurements of captive birds will have to be tested in the wild. Abstract - The sexual dimorphism in size was investigated in a galliform species with monomorphic plumage, the Rock Partridge (Alectoris graeca saxatilis), by measuring five morphological variables on 90 males and 90 females collected in the southern French Alps during autumn hunting seasons 1985 to 1995. The sex of all birds was determined by internal examination of the gonads. For all variables, males were significantly heavier and larger than females, whatever the age class (adults vs. juveniles). We also sought external criteria that would reliably separate male and female juveniles before the hunting season, using discriminant analysis of morphological measurements taken at weekly intervals on 106 hand-reared birds of known ages. Juveniles could be correctly sexed 90-100 % of the time at 8, 12 and 18 weeks of age by discriminant models containing 2-3 variables, i.e. body mass and tarsus length together or in combination with wing length or circumference of the head at the level of the eyes. Because hand-reared birds were a little heavier and larger than wild ones, discriminant equations developed for determining the sex of juveniles could not be applied to wild individuals. Sex criteria derived from measurements of captive birds will have to be tested in the wild.
Résumé – Le dimorphisme de taille en fonction du sexe et de l’âge a été étudié chez la perdrix bartavelle, Alectoris graeca saxatilis, galliforme au plumage monomorphique, en mesurant 5 variables morphologiques sur 180 oiseaux (90 mâles, 90 femelles) collectés dans les Alpes françaises du sud pendant les années 1985 à 1995. Le sexe des oiseaux a été déterminé par un examen interne des gonades. Les mâles apparaissent plus grands et plus lourds que les femelles, quelle que soit la classe d’âge (adulte vs. jeune).
Nous avons aussi cherché à identifier des mesures corporelles qui permettraient de déterminer le sexe des jeunes oiseaux. Pour cela les mensurations de 4 variables morphologiques relevées sur 106 jeunes, élevés en captivité et d’âge connu, ont fait l’objet d’analyses discriminantes. En utilisant la combinaison de 2 mensurations, la masse corporelle et la longueur du tarse, le sexe des jeunes peut être déterminé avec une bonne précision (90 à 100 %) à l’âge de 12 et de 18 semaines. En ajoutant une troisième variable (la longueur de l’aile pliée ou la circonférence de la tête), la distinction des sexes est possible avec la même précision dès l’âge de 8 semaines. Etant donné que les adultes élevés en captivité se sont révélés être un peu plus lourds et plus grands que les adultes sauvages, les équations discriminantes établies pour la détermination du sexe de jeunes élevés en captivité ne peuvent pas être appliquées à des jeunes oiseaux sauvages. Les critères de distinction des sexes devront être validés dans les populations sauvages.

Are temperature-loggers useful for studying nest disturbance in Rock ptarmigan Lagopus mutus?: 187-192
Novoa C. (1), Brenot J.F. (2), Thillet D. (1), Sentilles J. (1) & Ellison L.N. (3)

(1) Office National de la Chasse et de la Faune Sauvage, Espace Alfred Sauvy, F-66500 Prades. Tel : (33) 04.68.96.03.76, Fax : (33) 04.68.05.32.91, email : prades@oncfs.gouv.fr
(2) 2 bis chemin des bains, F-66500 Molitg-les-bains
(3) Office National de la Chasse et de la Faune Sauvage, 95 rue Pierre Flourens, BP 74267, F-34098 Montpellier cedex 5. Tel : (33) 04.67.10.78.00, Fax : (33) 04.67.10.78.02, email : l.ellison@oncfs.gouv.fr

Abstract - The incubation rhythms of three Rock ptarmigan hens were monitored during spring 1999, 2001 and 2002 in the eastern French Pyrenees, by placing programmable temperature data-loggers in the nests. We tried to classify incubation recesses into two groups, normal vs. atypical, in order to detect disturbance events. Incubation patterns varied noticeably between the three hens, but we could not find a clear relationship between incubation patterns and disturbance levels, defined as distance from nests to hiking paths. The only incubation parameter apparently related to nesting disturbance was the mean number of recesses per day. The highest values of two other incubation parameters (mean length of recess and mean time off the nest per day) occurred in the hen incubating the largest clutch, suggesting the possibility of an effect of energy requirements on incubation rhythm. Body condition before incubation could also have affected incubation patterns, but we did not measure it. Even if individual differences in clutch size and body condition might have explained most of the individual variation in incubation rhythm, we suggest that disturbance was perhaps an additional factor. Because the distinction between normal and atypical recesses is subjective, the number of the latter will represent at best a rough index to the level of nesting disturbance. Given that modifications in incubation rhythm related to disturbance might reduce egg or chick viability, any evaluation of the effect of nest disturbance on breeding success should include a measure of final reproductive output (i.e. ratio of number of young reared to number of adults).
Résumé - Les rythmes d’incubation de trois poules de Lagopède alpin ont été suivis en 1999, 2001 et 2002 dans les Pyrénées Orientales françaises, en plaçant des enregistreurs de températures dans les nids. Les sorties du nid ont été réparties en deux groupes, normales vs. anormales, dans le but d’estimer l’importance des dérangements durant l’incubation. Les profils d’incubation ont varié sensiblement entre les trois poules, mais nous n’avons pas trouvé de relation claire entre les profils d’incubation et l’intensité du dérangement, définie comme la distance séparant les nids des chemins de randonnée les plus proches. Le seul paramètre d’incubation apparemment influencé par le dérangement a été le nombre moyen journalier de sorties du nid. Les plus fortes valeurs de deux autres paramètres (durée moyenne des sorties et temps moyen journalier passé hors du nid) ont été observées chez la poule couvant la plus grande ponte, suggérant un effet possible des besoins énergétiques sur le rythme d’incubation. La condition physique des poules avant incubation pourrait également avoir joué un rôle, mais ce facteur n’a pas été mesuré. Même si les différences de taille de ponte et de condition physique entre les poules pourraient expliquer l’essentiel des différences des rythmes d’incubation, nous suggérons que le dérangement a été peut-être un facteur additionnel. Comme la distinction entre les sorties normales et anormales reste le plus souvent subjective, le nombre de sorties anormales représentera au mieux un indice grossier du niveau de dérangement des nids. Etant donné que les modifications des rythmes d’incubation, liées au dérangement, pourraient réduire la viabilité des œufs ou des poussins, toute évaluation des effets de ces dérangements sur le succès de la reproduction devrait inclure une mesure du résultat final de la reproduction, comme le rapport du nombre de jeunes sur le nombre d’adultes.

Distribution of the Dipper (Cinclus cinclus) in the Mugello valley (Florence, Italy) in relation to the environmental characteristics of  the streams: 193-202
Massimo Del Guasta  

Osservatorio Naturalistico Mugellano (ONM) c/o IFAC CNR Via Panciatichi 64, 50127 Firenze M.DelGuasta@ifac.cnr.it

Abstract - A survey of the presence of European Dippers (Cinclus cinclus) in the breeding season was carried out in the streams of the weakly-polluted Mugello valley (Tuscany, Italy) in the spring of 1999 together with environmental and macrobenthos data. 49 locations were examined. The discriminant analysis carried out on the data-set made possible the identification of six principal factors determining the presence/absence of dippers in the study area. The availability of suitable nesting-sites (man-made or natural) resulted to be the most important factor. The water-flow speed and the abundance of some macrobenthos taxa were other important factors. No significant correlations with the Extended Biotic Index (EBI) or with human disturbance were detected. 

Analysis of the spring migration of Honey Buzzards (Pernis apivorus) and Marsh Harriers (Circus aeruginosus) at two sites of Central Italy: 203-205
Nicolantonio Agostini (1) & Michele Panuccio (2)

(1) Via Carlo Alberto 4,  89046 Marina di Gioiosa Ionica (RC), e-mail: nicolantonioa@tiscalinet.it
(2) Via Mario Fioretti 18, 00152 Roma

Riassunto - Questo lavoro fornisce un’analisi dei risultati di due studi effettuati sulla migrazione primaverile del Falco pecchiaiolo (Pernis apivorus) e del Falco di palude (Circus aeruginosus) sul promontorio del Conero ed il Monte S. Bartolo. Questi due siti si trovano lungo la costa Adriatica dell’Italia centrale ad alcune decine di km di distanza l’uno dall’altro. Gli ornitologi effettuarono osservazioni contemporanee nel 1999 evidenziando un differente comportamento dei rapaci. In particolare, mentre sul promontorio del Conero gli uccelli sembravano intraprendere la traversata dell’Adriatico verso le coste della Croazia, sul Monte S. Bartolo transitavano prevalentemente lungo la costa. L’analisi dei risultati di questi studi, anche alla luce di precedenti ricerche effettuate in diversi siti del Mediterraneo centrale, sembra indicare che il Conero possa non essere adatto per effettuare un conteggio dei rapaci migranti in quell’area.

Rubriche

Commissione Ornitologica Italiana (COI), già Comitato di Omologazione Italiano. Report n° 16: 207-210
A cura di P. Brichetti, E. Arcamone, D. Occhiato & COI

Abstract - The following species were accepted for Italy (Cat. AERC: A - List 1a, 1b): Gavia adamsii (Friuli-Venezia Giulia 2003), Anthropoides virgo (Sicily 2002), Limnodromus scolopaceus (Tuscany 2002), Limnodromus sp. (Friuli-Venezia Giulia 2002), Streptopelia senegalensis (Calabria 2001, Pantelleria Is.-Sicily 2002), Phylloscopus fuscatus (Marche 2002), Lanius cristatus (Emilia-Romagna 2003; first record for Italy), Lanius (meridionalis) pallidirostris (Sicily 2000-01).
The following ones were not accepted (Cat. AERC: D, E - List 4): Balearica regulorum (Lombardy 2002, Veneto 2002 - 7 records), Falco amurensis (Sicily 1997, 2002), Streptopelia senegalensis (Emilia-Romagna 1999), Tringa flavipes (Emilia-Romagna 2002), Larus pipixcan (Sicily 2002), Acridotheres tristis (Puglia 2002).
The following ones were suspended (List 3): Puvialis dominica (Emilia-Romagna 1992, ringed in Great Britain in 1991), Larus heuglini (Sicily 2001), Tarsiger cyanurus (Piedmont 2001-02), Hippolais pallida (Pelagie Is, Sicily 1997), Phylloscopus

Book reviews: 211-212

Notices: 213

AVOCETTA