Great photo and great idea for the feeder so that you do not have to go out in the water to add food. This is a wonderful idea for private owners, however, in a public setting we would suggest to mount in the water so that humans (the biggest predator) cannot mess with the food.

As far as the corn, we are talking about filling for calories. The cracked corn will provide weight and make the swans feel full. The layer pellets do provide nutritional value, but the pellets alone would be like a human eating an apple. You get nutrients from the apple but it is an empty calorie food source. We want to add some weight (bulk) to the swans and the cracked corn is a good source for this goal. Hope this helps. The Regal Swan