The mystery of the vanishing ducks

We've had seven ducks, as described here. But over the weekend , during the day when we have been out , seven has become 5.

So 2 are AWOL.

They always stick together as   group, so we don't think  the absent ones have wandered off by themselves , and they are too big and heavy (and probably too stupid)  to fly away .

On one bit of the lawn where they waddle around  are some  scattered feathers.

And they  don't seem really keen on the fast-flowing burn , so we don't think the missing 2 have gone exploring over the edge of the pond

 There is another small pond surrounded by trees, just downstream of where the are now but no sign of them there.

trees next to the pond

 And we have had a good look around the pond and the land adjoining

moorland above the pond

But might there be a track through the moorland for a predator or interloper.

So whats happened to them :

Absconded  or Abducted ?