Duckling attrition

To recap, originally we obtained 2 domestic ducks (runners) which are part mallard, but they can't fly. And we can't catch them either. They're feral, I guess you could say. Last year one of them hatched babies fathered by a Mexican Mallard that took up residence here. Two of the progeny survived.

This year the two survivors each hatched a brood. The first one hatched 8 two weeks ago, but within a day or so, there remained only 5. Still 5 today. Yesterday, the second from last year hatched 3, which were relentlessly attacked. Yesterday I saw only the mother of the 5 attack them, but this morning I saw one of the domestic ducks attack the one surviving one. Now none of the 3 have survived. Perhaps the first 3 of the first brood of 8 met the same fate. Maybe the adults don't want too many ducks sharing their resources. Beats me.

Here is a rare photo of the five ducklings with their mother. Usually they're too spread out to get them together.