The Black Kite is a dark, long-winged bird of prey associated with open landscapes, wooded areas and water. Donau-Auen National Park describes it as approximately buzzard-sized and characteristic of the Danube wetlands, while also noting its rarity among Austrian raptors. That local context is more useful for a river visitor than the species' very large global range. BirdLife lists Milvus migrans as Least Concern, with a stable global population trend in the assessment read; this does not mean that every regional population is common. The River registry contains two separate reaches: the Austrian floodplains east of Vienna toward Hainburg, and the Rhine between Grafenwerth and Königswinter south of Bonn. Each has local occurrence support, but neither source read provides an exact numbered viewing season. A sighting may involve a bird travelling above the landscape rather than resting visibly beside the river.

Danube
Austria: Donau-Auen floodplains east of Vienna toward Hainburg, on the Vienna–Bratislava reach. Optional shore/backwater excursion; not a Passau or Budapest claim.


Black Stork
Black Tern