We have a single royal mute swan (mate died many years ago)that has been sitting on a nest for several weeks now. We cannot see if there are eggs and we have wisely left him/her alone. Why is he or she doing this? and does this give us a clue as to which sex it is? If it made the nest does this mean it is a male or does sitting on the nest for so long mean that there are eggs and thus it must be a female? Thank you - you absolutely have the best website for useful information about Swans.