When I first built them I didn't have any issues with predators but within the last couple of years, Yes, that's why I have gone back over the bottom 3 feet with 1" x 1/2" welded wire.
It's not necessarily the chicken wire, it is the fact that a raccoon can reach right though the 1" mesh of the...
A ground pen would definitely help! You can't have too much space when raising quail.
An actual 'sheltered' area is highly recommended, not necessarily a coop but protection from the elements and predators.
Here's a couple of pics of my pens (enclosures). I typically run 25 to 30 birds per...