Phenology of bluethroats At Dicle Bird Ringing Station

Bird ringing study has been performed at the Dicle Bird Ringing Station (Diyarbakır, SE Turkey) between 2003 and 2006, throughout five seasons of migration totally, one in the spring (2004) and four in the autumn. During 199 days in total, -apart from the re-trapped and controlled birds- 800 Bluethroats (Luscinia svecica L. 1758) have been ringed.Percentage of the Bluethroats among all the individuals of the species ringed at Dicle Bird Ringing Station was about 11.6% in average. Of all Bluethroats ringed, about 12.3% have been re-trapped, and three individuals have been controlled; one male, which was ringed in the autumn 2003, has been controlled in 2004 and 2006 autumn seasons as well.Maximal numbers of trapping occurred daily about 07:00 am in local time, and in the late afternoon increase once again to some extent in comparison to the remaining daytimes.Totally, 48% of the Bluethroats ringed were females and 52% were males. Among the females, 35% were adult and 65% were immature, while among the males 31% were adult and 69% were immature. Both in spring and autumn, the proportion of the adults to the immatures was approximately 1:2.The autumn migration began around mid-September and continued by mid-November. Main movements occurred in fluctuations about two to four days of intervals, the major numbers have been recorded from 5 to 13 October.The main migration periods for adult and immature individuals from both sexes did not differ considerably, it was however significantly different between the age groups: adults have migrated earlier and more concentrated, while the migration period of the immature birds expanded in a larger time span. The mean migration periods of adult and young individuals were 2 to 3 October and 7 to 9 October, respectively.Males were significantly heavier than females both for adult and immature individuals. No difference in the body mass of immature birds from both sexes has been detected. Throughout the autumn migration period, the average body mass have been increased about 0.041 g per day.The most assigned fat scores were 2, 3 and 0 in order, scores greater than 4 have been indicated only exceptionally. Average fat scores were higher in immature birds than in adults. The fat score has been increased averagely about 0.038 points per day throughout the autumn migration period.All the four groups of different age and sexes were different with regard to both wing and tail length. In average, adult males had the most extended wings and tails, while immature females had the shortest ones.