personally I think she lonely, id buy a young duckling for her as a companion, she wont feel intimidated buy a younger one and also it wont try to dominate her.
is the collar flat to his skin with all the feathers over mine got them off once of twice lol the little buggers, but just keep putting it back on and make sure its tight enough.
Maybe talk with your neighbours and explain the situation, but as for the crowing I know people that black out box them over night so they wont know when it morning, it worked for some but others as with one person I know the cockerel was older and was used to the times it was light, not...
okay for someone whos added a new hen to a flock how long can they stop laying for this reason generally sorry for all the questions and thank you for your reply's