On May 28th at around 8:30 pm. I saw 5 Common Nighthawks flying over the Otonabee River at 9th Line, accompanied by a very vocal male nighthawk calling then diving from a tree. He flew to another tree when he came up from his dive, and then went back to the original tree where he repeated both the call and dive again.
Susan Chow, Biology Department, Trent University