Presence and correlation between the numbers of Black-headed and Yellow-legged Gull was studies between 1998 and 2004 on Kolut fishponds in NW Serbia. Both species occurred there from February to December. Spring migration culminated in late February and early March. The period of the most intensive autumn concentration was from October to December. The difference between the numbers in all months as well as between the numbers in spring and in autumn was statistically significant. The period of the most intensive autumn passage of Yellow-legged Gull was from late October to early December. The difference between the numbers between the months was not statistically significant. A high concentration of both species in autumn and early winter was explained by high food availability during fish harvest when ponds were empty. Positive correlation between the numbers of two species thru the year indicated attractiveness of large flocks of Black-headed Gulls for Yellow-legged Gulls. This is especially true for the autumn period, when feeding niches and food is easily accessible. Correlation between the numbers of two species was negative in spring, when accesibility of aquatic animals is lower and large flocks of Black-headed Gulls are lacking.

Abstract In January 2014, the first ever comprehensive winter census of the Whitetailed Eagle Haliaeetus albicilla along the Danube River was conducted, using mostly point and transect counts. Altogether, 550-700 eagles were counted. The upper range of the estimate may in fact be more realistic because 615 km of the Danube were not surveyed. Birds were observed in every country along the Danube. Hotspots of occurrences were (1) the Central Danube floodplains - the area encompassing the lower Hungarian section (Danube- Drava National Park), Kopački rit Nature Park (Croatia), and the Gornje Podunavlje Special Nature Reserve (Serbia); and (2) the Danube Delta Biosphere Reserve. According to the Action Plan for the conservation of the White-tailed Eagle along the Danube, future winter counts should be made regularly, and lower variation in the resulting eagle numbers achieved by a higher degree of synchronization between individual countries. This study reinforces the importance of protected areas along the Danube as a backbone for the conservation of White-tailed Eagles and biodiversity.

Probst R., Nemeschkal H.L., McGrady M., Tucakov M. & Szép T. 2011. Aerial hunting techniques and predation success of Hobbies Falco subbuteo on Sand Martin Riparia riparia at breeding colonies. Ardea 99: 9–16.We analysed 291 attacks by 15 male Hobbies Falco subbuteo at 13 different Sand Martin Riparia riparia colonies in Austria, Hungary, and Serbia in 2004 and 2005. We predicted that the choice of escape strategy would be contextdependent and related to the condition and age of swallows and relative position and flight characteristics of both predator and prey. We predicted that swallows would be unable to escape falcons in a level chase and would not seek cover. We predicted that falcons would be more successful when juveniles were present. Hunting success rates were higher during the swallows' post-fledging period, probably because of the weaker flight performance of juveniles. Invariably, adult swallows tried to outclimb falcons, while probable juveniles also tried to escape to cover. Hobbies most often attacked adult swallows by a fast approach from great heights and distances. In contrast, in the post-fledging period, when juveniles were available, low horizontal attacks and long climbing chases were common. In doing so, Hobbies at times prevented juvenile swallows from taking cover and were, in turn, sometimes able to outclimb and capture them. Significantly more attacks were abandoned during the post-fledging period. Sand Martins were unable to escape Hobbies in a level chase. Individual male Hobbies showed no difference in hunting success, maybe because all were experienced. The number of Sand Martins present at the time of attack did not influence hunting success. The results are discussed in the light of the anti-predator strategies of animals living in groups.

Numbers of breeding pairs of breeding birds and breeding density are established by territory mapping in Limanski (12.9 ha), Futoski (8.26 ha), and Dunavski (3.9 ha) Parks in Novi Sad from early March to late June 2007. In Limanski Park 11 species of breeders were found, the most numerous being tree sparrow (Passer montanus). Futoski Park had 15 breeders and the most numerous were great tit (Parus major). The smallest number of species (9) bred in Dunavski Park, with great tit as the most common breeder. The greatest density of breeding pairs was recorded in the largest park (37.7 pairs/km2). Hole-breeders dominated in Futoski and Dunavski Park, but their number was the same as the number of canopy-breeders in Limanski Park. Measured with Sorensen index of similarity, the greatest similarity was found between breeding avifauna of Futoski and Dunavski Park (72), then between Futoski and Limanski (61), while the smallest similarity was found if we compare breeding avifauna of Dunavski and Limanski Park. Compared with breeding avifauna in other parks in Central Europe, breeding avifauna of Novi Sad parks is relatively poor.