I'm at a loss about what I can do about this.
I thought about putting chicken wire over the top of the duck run, but that wouldn't really be sufficient, would it? Yet anything more solid, e.g. tarpaulin, would get shredded by the wind in a matter of hours.
If I simply lock them into their house, they will have no light and no pond. Plus the house is 'cosy' to start with.