They have 2.1 birds, but I only saw the males on a brief visit. The water is very clean at this site, which is why these birds are kept here. I presume that the source is in the rocks and the waterfall is the main outlet. The wooden boards protect the food bowl and the mesh protects the ducks from other birds. Both the drakes are pinioned.
Arundel Wildfowl and Wetlands Trust, February 2009.