I've got 2 female khaki campbell ducks...well..at least that's how they were sold to us!

At first we used to get two eggs per day (one egg per duck?!) but over the last few weeks, have only been getting one per day.

When I let them out on a morning, they head straight for the pond and after a bit of head bobbing (duck owners will know what I mean!) the larger duck 'mounts' the smaller duck, holds her head under the water and appears to be 'mating' for about a minute or so before the smaller duck 'escapes' and they both wash themselves off in the pond.

Is this normal?!......do female ducks imitate mating?!