We have the same pair of trumpeter swans that returned to our lake in May with the year old cygnet from last year. They chased the year old off, mated several times on our lake, and then left to nest on another small pond 2 miles away. We have a small airplane so we flew over several times to check on them after the eggs hatched, and sure enough they did the same thing this year and somehow got all 5 babies back over to our lake when they were only 2-3 days old. We think it is very unlikely they walked 2 miles thru the woods and crossed a busy road. Is there any way they would carry them in flight? In their mouth or can they tuck them in under feathers somehow? We know they are the same pair because it is the third year they have come back and they are very friendly - especially momma. By the way - the year old cygnet from last year did come back a few times while momma and papa were nesting on the other lake - he (or she) found a mate (or friend) already - so that was nice to see.