Northern Prairie Wildlife Research Center
Flax straw is the best material for nest bales because it is coarse and resistant to rotting. In areas where flax straw is not available, a good substitute is coarse grass hay, such as canary grass, or grain straw. Alfalfa hay is less desirable because it tends to deteriorate rapidly.
Where ice is adequately thick, it is possible to roll the bales out by hand or use a tractor for placement. To insure bales do not tip over when the ice thaws, they should be placed on end in a large hole cut in the ice. Although woven wire has been used to hold bales together, we do not recommend this unless you plan to remove the wire from the pond after the bale deteriorates. Welded wire or chicken wire should not be used because it could entangle the goslings or ducklings as they attempt to leave the nest. To reduce predation, bales should be placed at least 50 feet from shore in 18 to 30 inches of water when possible. Initially, bales should be placed 150 to 300 feet apart with no more than 1 every 1 to 2 acres. As the number of bales being used increases, more bales can be added.