We have a foot bridge which crosses the Red Deer River at the River Bend Golf Course. There are two large cement girders which support the bridge. The bridge is about 150 meters long.
In the summer there are hundreds of cliff swallow nests on the girders. The birds find it easy to attach their nests to the cement girder. Since the bridge obviously crosses the river there is a tremendous insect population. This makes it ideal habitat for the swallows. There is also a bank swallow colony on the river bank at one end of the bridge. So in July there are hundreds of birds around this bridge.
Now I get to the merlin. I found a merlin sitting on the bridge railing one evening. I also noticed that the swallows where swarming overhead and making an awful racket. One hunting tactic that merlins use is to get under a flock of birds . The birds try to fly up and away from the merlin. All the merlin is waiting for is for one bird to drop out of the flock and then the merlin dives and catches the bird. Birds that are old , sick or young will become exhausted and drop down to find a perch. This merlin didn't bother to fly and keep the birds rising. He just sat on the bridge rail waiting for a meal to drop out of the sky for him. Very smart birds!