Ithaca's Food Web is a great blog from Allison Fromme - thanks for the write up!
"The ducks did eat the slugs, but the weather last summer was unusually
dry, so the slugs were not as problematic as previous years. Steve says
his biggest surprise was that one breed, the Muscovy, ate both slugs and
the mushrooms -- not ideal if you aim to sell mushrooms. "The heritage
breeds (Cayuga and Swedish blue) were notable foragers, often exploring
the forest floor before heading to the food trough," he says. "