Coturnix should be kept in groups of 1 male to 5 females, too many males will fight and pick on the females. They're very predator-vulnerable, as well, make sure nothing can get to them.
They need shelters to hide in, and you should make sure they always have food and water available. If you can provide it, they'll do better with more space. That's a lot of straw- I'd go with a thinner layer that's changed frequently to be sure it's clean and no mold can grow under the layers.