There is a small lake/large pond that I walk around daily [just a half mile around], there have been a Trumpeter swan pair that have showed up to feed on a regular basis, one or both fly in and then fly out after several hours. All of a sudden there are 4 cygnets with them, I am 100 % sure there is not a nest on the lake, and I'm also 100 % sure where they came from, but my question is how did they get there.

A friend living on another small lake has been watching them and the day they disappeared from her lake, they appeared at mine. There is at least a half mile of solid, thick [with old/new cattails] wetlands between the lakes, I can't imagine the swans being able to walk through it let alone the very tiny cygnets, its not like some wetlands where you see a muskrat trail going through, there is no path or openings at all. The cygnets are quite tiny. This photo was taken about 5 days after they showed up so they were even smaller when they arrived. This is in Minnesota.

Thanks!