Dad is chasing babies

[Harriet]

I'm new to raising ducks.  I had 2 clutches but because of space issues, I let all of them go to new homes except a few.
I now have five of the 6 week old girls & Mom & Dad who are 1 1/2 yrs old.
The girls stay penned up most of the time. 
Mom & Dad are free range.

I do not want any more babies.  I tried to catch Dad but have not been successful.

Every afternoon, I let the babies out to forage some.
I know Dad has nothing but SEX on the brain but I want to know exactly WHY he chases the babies? 
I don't think it is to mate because he did it when I had boys too.

He is really aggressive towards them!   He huffs & does the wing spread & the whole bit!
He bites them & chases them either into the water (I live on a canal) or back into their pen.

Is he trying to keep them away from the mother?
Is it territorial?
Is it sexual?

I have run interference & chase him away but he is very determined & often will come back from behind a bush or tree in another part of the yard. 
He sneaks up & starts again.

Is there anything I can do to stop this without re-homing him?

HELP PLEASE!

Thanks
Harriet

[Vintage Chix]

Hey Harriet, I didn't check your profile, don't know where you live or what your yard situation is. Did you  let Dad see the babies when they hatched or did you keep the clutch away from him? I have never had problems with Dad and female offspring, but only with male offspring and only when the ducklings got about six months old (breeding age). So, I can't say why dad is chasing his girls. Can you possibly fence him from the gals but let him see them,  it is possible he might get over this. Would it be possible to reverse the housing situation? Keep dad penned and let the youngers free range? Are you SURE they are females? It would be pretty hard to tell sexes at that age (six weeks old). Seems the easiest thing to do would be to keep dad penned till mating season is over...probably early October. Rather than re-home him (and he would probably go into "freezer land"), you might invest in some fencing and extend an area for him to be kept from chasing the ducklings. Just my $.02 worth...and good luck.