Turkey lies on one of major migratory routes between Palearctic and Afrotropical regions.Despite its importance for many species, few studies exist on bird migration over Turkey. In this study, autumn migration dynamics and stopover behaviour of Willow Warbler (Phylloscopus trochilus), a small insectivorous passerine, was documented and analyzed at Manyas KuScenneti National Park (northwestern Turkey). Birds were mistnetted, ringed, measured, weighed and fat-scored from mid August in 2002 and end of August in 2003 to end of October in both years. Totally 543 and 929 Willow Warblers were ringed in 2002 and 2003 respectively. For 2002 and 2003 respectively, fat score values (mean&plusmn / SE) are 4.63&plusmn / 0.06 and 3.84&plusmn / 0.05 and body mass values are 11.38&plusmn / 0.07 and 10.37&plusmn / 0.05 grams for birds captured the first time.Fat scores in 2003 show a bimodal distribution with peaks of T2 and T5, indicating populations or age classes with different migratory strategies.The number of retraps constituted 9.2-12.1 % of the total in 2002 and 2003. In both years,minimum stopover length ranged from 1 to 15 or 16 days with a median of 5 days. The majority of the retraps put on significant fat in both years. Retraps continued to put on weight for up to two weeks after they arrived. In this first ever study documenting passerine migration at Manyas KuScenneti National Park, it was revealed that such wetlands provide crucial stopover habitat for many migrant passerines, enables them to gain necessary fat loads before crossing two ecological barriers,the Mediterranean Sea and the Sahara.

Seasonal long-distance bird migration between wintering and breeding grounds is oneof the most remarkable phenomena in the history of life on earth. Migration strategies androutes vary greatly. Some birds migrate in social groups whilst others migrate alone at night,some cross few hundreds of km whilst others cover thousands of km. Avian migration has beenstudied extensively nevertheless numerous important questions remain unanswered. This studyaims to contribute to the understanding of the genetic basis of the innate migratory program ofa common songbird.From results of classical crossbreeding and orientation experiments with captiveblackcaps (Sylvia atricapilla) we can be sure that songbird migration directions as well asdurations are traits that are being inherited genetically and most likely have a multi-locusgenetic architecture. The chosen model species for my project is the willow warbler(Phylloscopus trochilus), one of the most common leaf warblers in the Palearctic. The willowwarbler has a continuous breeding distribution from the coast of the Atlantic to the coast ofPacific. They overwinter in sub-Saharan Africa. Three subspecies have been recognized: P. t.trochilus (breeding in central/western Europe and migrating SSW to western Africa), P. t.acredula (breeding in northern and eastern Europe, migrating SSE to east and south Africa)and P. t. yakutensis (breeding east of Ural Mountains, presumably migrating to SouthernAfrica). Morphological differences across the willow warbler subspecies are subtle and it has been previously shown that genome wide FST is close to zero. The low level of neutral back-ground divergence offers a good system for studying the genetics of passerine migration. This report contributes with novel data on phenotypes and genotypes of the subspecies yakutensisstudied at Chaun river delta, at the very eastern range limit of the species. As a proxy for thewintering location of yakutensis I used C and N stable isotope signatures from winter grownfeathers and inferred wintering range to be in Southern Africa. I genotyped 36 yakutensis fromChaun on four nuclear markers, of which three are located on the only divergent regions thatdiffers between the migratory phenotypes in Europe + CLOCK gene (a candidate for timing ofmigration). Analyzes revealed that yakutensis, despite strong differences in migration direction,distance, timing and wintering ground location cannot be separated from acredula genetically.