About an attempt of kleptoparasitism of Jackdaw on Black-headed Gull. -
I.R. Merzlikin. - Berkut. 12 (1-2). 2003. - P. 165.
This case was observed on a lake in Sumy (NE Ukraine). A flown by Jackdaw attacked a Black-headed Gull caught a bleak. The gull has dropped prey, but the Jackdaw could not catch up it. [Russian].