How long do swans sit on their eggs?
After the nest has been built, which typically takes 2-3 weeks, the egg laying process begins with an egg being laid every 12-24 hours. Once all the eggs have been laid, which can take 2-3 weeks, they will all be incubated (ie sat on to start the growth process) at the same time with hatching usually 42 days (6 weeks) later.