Drake attacking ducklings

Looking for some advice on what to do about my Aylesbury drake attacking two new ducklings (2 weeks old).  I separate them at night but free range my ducks during the day (over a large area), however, the drake keeps hunting down the ducklings and attacking them.  One of the ducklings now has a couple of bald patches and I've just noticed that the skin underneath is broken as well  .  Is the only answer to keep the ducklings and mum cooped up all day??  Any suggestions what I could use on the duckling's wound to help it heal or is it best left alone?

Thanks for your help 

Drakes can be very rough with ducklings and as a result when mine started coming out I got them a dog/small pet pen to go in so that they could be moved around but be safe from the boys until they were about 6 weeks old and big enough to look after themselves. As for the wound have you got some purple antiseptic spray as this would be best to spray over the area? 

Thanks Sue, thanks Caralou.  I guess I'm just going to have to keep them separated - perhaps let the drake out for a while and then put him in so that I can let out the mum and ducklings.  Do you mean just normal antiseptic spray ie for us 10-toers  ???

This is a spray you can get from horsey/feed shops. It is healing and covers up any redness that may encourage an attack. It also deters flies.

The antiseptic spray you mention is called gentian violet - it's a natural antiseptic and dye and colours any pecked raw areas bright violet (it will eventually wear off). You should be able to get it from any country store that sells animal feedstuffs etc. I bought mine from a Countrywide store, but if you can't get it locally you should be able to order it online for next day delivery for about £10.00.
As for separating the ducklings, when I need to introduce new hens to my flock I use a very large dog cage (48" long by 24"wide) that I bought new off Ebay for £32.00. It has a solid metal bottom so is easily cleaned and gives them enough room to wander about without risk of pecking from the other birds. I put them in that for a day or two after their quarantine period and put it into the main enclosure near the feeding station, so they get lots of visits from the hens as they come to feed. You get squabbles through the bars, but the other hens can't get their beaks in to cause any damage. That usually sorts the worse of the "pecking order" problems, with the odd squabble when they are eventually released into the flock.
You will need to cover the roof though as it is not weather proof or sun proof, so they will need a shaded/rain proof area in the cage - I cover about 18 inches of the rear of the cage for this purpose. I wouldn't be without mine as I've used it to death and it packs away into a flat pack for easy storage when not being used.

Is the drake a favorite pet.  If not it may be time to part company with him in some way.  You could find out if there is a local bird auction coming up, there often are in autumn.  Animals and birds have their own personalities and maybe his is just not very nice. And you sound as if you have other drakes if you still need fertile eggs

Of course there are other options............

All the best
Sue