Mallards won't eat fish on purpose but might injure them while rooting around for things to eat. But.....they can indirectly kill your fish by bringing all sorts of nasty parasites to your pond. The poop the produce will also drive your ammonia levels up and overload your filter. As cute as I am sure they are, I would really discourage them from visiting.

Sorry, but mallards are very happy to eat as many small fish as they can catch. They are not great at catching fish, but they do love to eat 'em.

ohhhhhhh weeeeeeee I will have to go check the fish again. i think they were all hiding from the intrusion but maybe they got eaten...

I keep finding the skeletal remains of fish on the beach of my lake surrounded by duck prints. So I'm assuming the mallard is catching and eating them all. But I do not know, maybe he is just a special breed :p

what about black crested ducks, is this a mallard exclusive or any ducks. will they eat baby fish? I have an acre lake that is quite deep full of cat, perch and bass. We put geese and 4 ducks on for foliage clean-up. Some are saying they are eating the babies. Don't know who they can tell cause the ducks swim away as soon as anyone come near. I raised them in a pen for a while and know they smack ninety miles a hour in the mud for stuff, so not sure if that's what they are seeing. We are arguing about whether they are eating the fish. Help!

a duck ate 4 small fish I bought my dad for his birthday they were probably 2 inch long and had them since August last year :-( he caught a duck swimming on the small pond, it ate 3 and left one dead floating on the pond...gutted :-(