Hi, thank you so much for your reply, I am so grateful. Unfortunately we only moved here in November so I don't know if they have had any cygnets last year but they had chased off a lone male and took over a month or two after we moved in. This is great news as I was worrying for them and if they want to move their whole family in they are very welcome. Thank you again for taking the time to explain and thank goodness we have experts such as yourself to help. Have a great day lisa