Chicks moved into modified garden box

At the end of February, we purchased a variety of chicks from our local farm supply store. They have been in our garage in a children's wading pool with a heat lamp hanging from the ceiling and plastic bird netting to keep them from flying out. With about twenty birds, this has been a decent size to keep them until they outgrew that space. Lately, they have started getting spooked and flying around their confined space when the kids make too much noise or when it is feeding time. Now that the worst of the cold weather seems to have past, it was time to put them outside with the other animals.

The chicks are large enough with mature feathers to handle the extremes in temperature at night and during the day, but I don't think that they are ready to be mixed with the existing flock. Introducing new chickens can always be a challenge with the new ones always getting picked on, even if they outnumber the older birds. Here is what I did to prepare an area near the existing flock but to provide protection from them:

1. Board up the access from the chicken run to the chicken coop where the mature hens are laying eggs. The coop has an access door to the outside, so they don't really need to be in the run except for protection.
2. Build a temporary fence out of deer netting and T-posts to keep the birds in and hopefully to prevent wandering predators from threatening the chickens. We have had threats with neighborhood dogs, raccoons, and a family of foxes. Our Great Pyrenees has done his part to scare off many of the threats. Even with the help from our dog, we still lost a few chickens that were roosting outside the protected chicken run over the past few months. (I think that it was from foxes, based on similar issues with neighbors with chicken problems.)
3. The chicken run is really a long garden box enclosed with hoops of electrical conduit and poultry netting. The mature chickens have been protected in this area the whole winter, accumulating layers of straw, wood shavings, kitchen food scraps, and their own manure. After a long winter without being turned, the lower layers were pretty compacted and starting to stink. I didn't want to put the new chicks into this toxic area so I cleaned it up by using a rototiller to mix it all up so that it can decompose more effectively. This material fluffed up to about eighteen inches worth of partially composted bedding.
4. Finally, I topped the garden box with a couple inches of fresh straw. The chicks are bound to scratch down to where the old composting bedding is, but I'm hoping that it is composting well enough to not be a problem of introducing bacteria levels that the new birds can't adapt to.

The older birds seemed very intrigued with the new chicks peeping from the chicken run. Several of them stood near where they could watch them while the chicks mainly huddled all bunched up in the corner. Once they get used to each other in a week or so, I'll open the outside access and let the chicks out to mingle with the older birds.

Later this summer I plan to build a new chicken run for the birds to use. This will be the third garden box, the first being planted as a garden this year. In order for the current chicken run (second garden box) to be able to be used for planting vegetables next year, I'll want to add some additional soil amendments, mix it in, and let it compost in place over the winter without additional chicken manure. (Right now, it would be too "hot" for plants) Ideally it would sit for a whole year, but hopefully six months will be good enough as long as I mix it every now and then.