Tell me about ducks

[Mandalorian]

Last year DH and I fell in love with a bungalow that has a large natural pond in the garden. The pond is huge and houses several ducks (as well as visiting geese). We've finally had the good news that we can buy the bungalow and I am stupidly excited - mostly for my pond!

The ducks are wild as far as I can gather, no idea of species though I think there are moorhens on there as well. I know wild ducks are very different to domestic ducks and I want to know how much or little I should be doing.
Am I doing harm feeding them duck food? Do I need to be watching for disease etc?
Because I'm a soft touch my first thought was to build a duck house, but I realise now this might leave them vulnerable to foxes.
Can I do anything to help over winter?
Or should I just leave everything alone and let nature take it's course? HELP!

No-one answered you! If they are wild ducks, it is fine to feed them (but not bread!) - lettuce, peas, corn, grain, etc (have a google and see). I would have thought a duck house (in the actual pond, not on the bank), if it is up out of the water a bit on a post with smallish entrances , for instance, would be OK for the ducks with regard to foxes. I'd try googling duck keeping forums (they must exist!). They won't be safe without a duck house either if a fox wants them. If they are indeed not domestic, they will get by in the winter fine (but you feeding them would be very helpful). I imagine they will come and go as some are migratory. You probably won't get much in the way of frogs/spawn though as ducks do tend to eat all that. In my previous London garden (near the North Circular road), we had a big pond and mallard ducks visited from time to time. One duck tried 3 times to lay eggs and sat on them for ages (in a gap between the garden shed and the house wall but a fox or rat came along and we never saw her again (hope she got away) and all the eggs were taken.