Rock & Roll boven de Amelandse kwelder: kleptoparasitisme van Blauwe Kiekendief Circus cyaneus bij Torenvalk Falco tinnunculus

During a hike on 13 May 2021 a hunting female Hen Harrier was observed around noon in the transition zone between dunes and salt marshes of the Wadden Sea Island of Ameland (NL). The bird suddenly switched from regular low-speed hunting at low altitude to a straightforward, fast flight directed at a distant male Kestrel Falco tinnunculus. The short pursuit of several seconds culminated in a roll-over manoeuvre during which she switched from flying above the Kestrel to dipping below and seizing the prey (probably a vole). Although the Kestrel shortly held on to the prey, it was successfully taken by the Hen Harrier and carried away. The case of kleptoparasitic behaviour here presented is a photographically documented addition to the vast literature of this phenomenon.