We had drawn up plans for chickens, when we were given five Saxony ducks somewhat unexpectedly. We were told they were about 5 years old at the time and likely towards the end of their egg-laying years, but mostly self sufficient on their own.
They turned out to be far from done laying, once they got settled we had an egg from each of our girls almost daily and a few have even hatched out several new broods.
We do supplement with some organic feed and minerals and make sure they have plenty of water, but they are indeed active foragers all over the property and do fend for themselves for the most part.
The ducks tend to lay eggs in random locations but will sometimes collaborate on a nest if they find a nice spot. Every time we find a nest though they'll relocate to a new spot, which can be a bit tedious. They are living the best duck-life we can provide them, and it shows in their general health and productivity.