coturnix with pecking problem

[Mykee]

I have 5 coturnix quail; 1 cock and 4 hens. They keep pecking each other, especially around their eyes. There isn't one particular quail doing this, so seperating 1 would be useless. The cock is also mating with 1 of the hens too much, and her head is bald and very sore.
Do you have any suggestions to keep them from pecking each other, or any good websites or books I could read?
They are 1 year old, and my first quail, and whenever I look stuff up online, its for meat quail and does not cover things like this.
Also, how long do they live?

 

[JJMR794]

A. Are You Absolutely Sure Its 1 And 4? If So How?
B. How Big A Pen?
C. Any Sore Areas Can Be Treated With Blue Cote/ Wound Kote But If Not Seperated So The Area Gets A Chance To Heal It Will Not Help
D. I Have Had Multiple Coturnix Make It To 8 Even 9 Yrs Old

 

[sfw2]

How large an area are your birds kept in? Sometimes, overcrowding will make pecking worse.

 

[Mykee]

They live in a rabbit cage with a solid bottom, about 1 1/2' by 3 1/2'. I know there is only one cock because I have gotton four eggs per day, only one "crows", and my breed of coturnix has red on the cock's breast, and only one does.

 

[Wifezilla]

What is the protein percentage in their feed?