Ducklings pecking

[chdkgu]

I have 7 Khaki Campbell ducklings that are just about 5 weeks old. This morning they started some serious pecking at each other and 3 have some large bloody areas. What is making them do this, and how can I stop it. I tried giving them more space, a large outdoor pen in the sun, but they still attacked the same three and I was concerned that even in the warm sun they would get too cold. The 3 that were injured went back in the basement brooder, and I have separated the other 4 by putting 2 each in large rubber made bins. This set up will not work for long as they are growing so fast. I currently have 8 chickens in a 100 square foot coop - should I put the 4 non injured ducks in with the chickens? everyone will free range during the day, but will the chickens hurt the ducklings at night?
Is this serious pecking normal and does it stop as they get older. In a few more weeks I plan on having all of them free range which I suspect will solve the problem, but what can I do until then?

 

[Kevin565]

Welcome to BYC!

What feed are they currently on? Did they just peck or did they eat the feathers as well?

 

[chdkgu]

We have chicks too so everyone is on Chick starter. They are pulling out feathers on the wings and just behind the wings. I don't see any of them eating feathers. Three of the seven are being targets, but I can't tell if it is more than 1 doing the biting. The chicks are in a separate brooder now that everyone is bigger. When the chicks started to peck a bit, I was able to get them to stop by giving them a seed block to peck on instead.

 

[Kevin565]

I used frozen heads of cabbage to curb my peafowl of their feather picking habit. This behavior will most likely stop whenever they start free ranging but some birds just don't seem to behave when in smaller quarters.

 

[chdkgu]

Thank you for the tip. I am hoping for the weather here in MI to improve so they can be outside. We have had a very cold winter nad spring is just not coming as it should. I will try to keep everyone as entertained as possible until the weather turns.