About 12 years ago, when our 1 acre lot was still close to fields, we had a pair of mallards nesting in our backyard. We just had removed a wooden playground structure, but the concrete foundations were still there. Thus, we could not mow this part and the mallards chose this as nesting site. From time to time we took a peek, and there were six eggs and later six chicks. One day, the mallard hen just walked away with the chicks in tow, through a hole under the backyard fence. Fortunately, it was a Saturday, and even more fortunately, I was just looking at the backyard when it happened - the exodus took less than two minutes.
Another episode from about the same time. We had a trampoline in the backyard for the kids. One day one of the kids left a plastic owl lying on the trampoline (the kind of plastic owl you use to deter small birds from your patio or your herb garden). Well, a young Swainson's hawk must have thought that a dead owl makes a nice meal, and it landed on the trampoline. Well, the fact that the owl was not made of flesh and blood must have been a disappointment. But the real problem came when it wanted to fly away. Raptors are not helicopters or VTOL airplanes and need some space to take off. However, the trampoline had a safety net which did not give sufficient space. Fortunately for the hawk, my son and I had seen the whole dilemma. We dismantled a part of the safety net, always aware to stay away from hawk, until it finally could lift off.