Know nothing about ducks or nesting success rates so can't help you there.
But as an aside from chicken rearing, you don't want to use cedar shavings in nest boxes b/c the phenols given off irritate the respiratory system of birds making them more susceptible to infections. Cedar coops and building materials are fine as they air out quickly.
Found this on a real quick google search, looks like about 60-80% hatch rate?
Factors that can change hatch rate of chickens at least include how long the eggs were stored and the conditions the stored eggs were under. If there were 12-15 eggs, the oldest eggs would have been 15+ days old. With chicken eggs at least, eggs stored more than 10 days under optimal conditions start to have a great decline in hatchability. If there was a hot or cold spell in the area when they started laying eggs, this could have easily rendered the first week of eggs useless.