Hello... Yesterday afternoon (no, this is not an April Fool), I watched a pair of Fish Crows in Guelph in the vicinity of the Stevenson-Palmer intersection, (This is about 3 km north of the University of Guelph Arboretum, where the speceies was reported a few days ago.) The Fish Crows and a pair of American Crows were calling back and forth and swooping about for three or four minutes in a sort of mutual aerobatics interaction that was not evidently aggressive. cheers, Martin Daly