My SIL & brother were proud to announce the arrival of 11 little Pacific Black ducklings ... They had a wild duck sitting on her eggs for 28 days ... on the little island in their pool . We had a party there Saturday night and she wasn't worried - but watched everyone watching her LOL. Sunday was 28 days - crack crack crack - they heard the eggs starting to hatch (over a few hours too). Sunday we went back to eat the party leftovers and saw the eggs hatch.
They called WIRES two weeks or so ago - who came out and told them the 26 - 28 days gestation. The kids even swam in the pool around her ...while the eggs were still hatching keeping their distance.
After they hatched she kept them close and underneath her .Monday she took them swimming for the first time .Then, when no-one was watching she marched them off up the back to the neighbours dam. She only left the eggs once a day usually for about 30 mins - very interesting