In this paper are presented the results of a study of the diurnal bird migration in relation to weather conditions at Budaki salt lake, Dniestr estuary, Ukraine, during 1978-1990. Migration was studied for 240 days each year. From 100.000 to 270.000 migrant birds, belonging to 50 different species, were counted every year.
During the year 1995, on the rivers Paglia and Formone (central Italy), the territoriality of Stone curlew Burhinus oedicnemus has been studied by play-back. Territoriality starts some 20 days after the arrival at the reproductive sites. It has been noticed a relationship between territoriality and positive reponse to play-back. In the area examined it is normal to register a second clutch per year (by a percentage of 77.7% of the cases). On large scale census, the use of play-back method is advisable during the month of april.
he Dipper population breeding in a 12.5 km stretch of the River Posina (Vicenza Prealps, northeastern Italy) was studied during 1991-1996 and results were compared with those from other researches throughout Europe. The breeding density (mean = 1.46 ± 0.04 pairs/km) was relatively constant through years, but it was highly variable along the stream. A total of 127 nests were located, most of them (81.1%) built in artificial sites. The median laying date was 9 March for first breeding attempts and 23 April for second ones. Laying dates of first clutches were influenced by pair age and habitat features of the different stream stretches. The overall mean clutch size was 5.11 ± 0.54, comparable with values observed in northern populations of continental Europe. Clutch size did not vary during the season, apart from a sharp decrease in May. Of 54 successful first nestings, 25 (46.3%) were followed by a genuine second brood. The overall percentage of nests producing at least one young was 80.8%, second clutches being more successful than first and replacement ones. Young from clutches laid in different periods showed different recapture rates, nestlings hatched around mid-May showing the highest recapture rate. The annual adult survival rate, estimated from between-year recaptures, was 56.8%. Posina Dippers exhibited a strong territory fidelity both during the breeding season and in the following years.
Biometrics of adult and nestling Dippers were studied along a 12.5 km stretch of the River Posina (Vicenza Prealps, northeastern Italy) during 1991-1996. Results were compared with other European data. Biometrics were collected from ca. 250 birds, mist-netted all year round. Independently of age, Dippers were classified as males or females if their wing length was above or below 91.0 mm, respectively. Body mass reached the maximum value during moult (August) and the minimum one at the end of breeding season (June). Growth rate of nestling Dippers (k = 0.350) did not differ from that observed in the Swiss Alps.
Survival rates of adult Melodious Warblers were estimated by capture-mark-recapture data, analyzing capture – histories of 169 individuals with the program SURGE. The annual adult survival rate was estimated at 54,1%. Breeding density in the study area was 16 – 18 pairs/8 ha in the 1992-95 period, whereas decreased to 13 pairs in 1996. Philopatry, phenology of migration and of reproduction are also discussed.
Occupation of nest-boxes by six middle-size species of birds in unwooded areas of Iberian peninsula was studied. The most frequent bird species nesting in boxes were Rollers (Coracias garrulus), Eurasian Kestrels (Falco tinnunculus) and Lesser Kestrels (Falco naumanni) suggesting that nests availability is the principal limitation for the colonization of open areas by these species. Unlike, Little Owls (Athene noctua), Scops Owls (Otus scops) and Barn Owls (Tyto alba) were sporadic nester in the boxes although they nested in the study area. The occupation trends varied between the species. The Roller, the Eurasian Kestrel and the Lesser Kestrel increased their occupations during the study period, possibly as a consequence of the selective advantages of artificial nest-sites in relation to natural nest-sites in the area.
