I completely understand you woes. I lost four quail in a span of two weeks. I have double wired bottom pens, 1/2 hardware cloth laid over heavy bars but had predators grabbing them through the front of the cages. Set live traps all around the bird cages and on my prpety and caught the culprit in two nights. No losses since.
I had two of mine disappear a few weeks ago and I put them in a new pen made from 1/4 inch hardwire cloth. No losses since. I think mine was a small animal since it didn't get my ready to eat chickens roosting in their open coop (I closed it for a few nights after that)
I doubled up on chicken wire for now, I think I need to redesign things a bit. I have 6 jumbo coturnix coming this week. I think my final design will have two runs side by side with jumbo coturnix on one side and Tennessee red bobwhites on the other side. I was thinking of making each run 4 feet wide, and eight feet long. I designed a house that both could share, but with a board in the middle to separate them , this way I have easy access to both types of eggs. And no fighting. Has anyone ever had there's perch? I wanted to be nice and give them some perches but I read that some have never had theirs perch at all . I will also be places bushes in them to attract bugs etc for their excessive and treats. I love watching them chase bugs haha, my chickens are great at catching the flies.
Yep I have to add sand a lot though because my pan isn't all that deep and they throw it out. I just go down and get river sand, but if you don't have access to it you could always use a deeper pan and put a 2x4 in the inside and out in case they have trouble getting in/out.
lol good luck. Hey have you ever had an odd colorless egg from your quail? Mine laid a weird egg just the other day and I started a thread but no one got back to me. Here's what it looks like.
The bottom was blue also. It was just weird I found a solid blue egg in with them too.