Hi,
I saw one about 10 days ago, looked like a vagrant at that time. But today, they were 2 together playing in the air. Some moves they were making look like aerial display, like they were having fun together.
http://maps.google.ca/?ie=UTF8&ll=47.347896,-79.386005&spn=0.055246,0.109692&z=13 . Center of the map
Also a fight between 3 males Blue-winged teal for a lonely female.