UPDATE 4 April 2011
Finally! A bird-free zone!
I still have a few minor details to wrap up, but the "anti-aviary" is virtually finished--just in time to save most of the apricots, as well as all the peaches, apples, plums, and persimmons. My feathered freeloaders start pecking the green apricots when they're only about the size of my finger tip, so they've already gotten a few, but hopefully that's the last they'll get from now on!
After the low, chicken wire, perimeter fence was in place, but before installing the bird netting, I noticed little hoof prints in the dirt along with signs that a javelina had been rooting around for melon rinds in the compost under the Fuyu--evidently it shoved the top of the wire down just far enough to topple into the enclosure. Fortunately, it didn't bother my figs. I reinforced the fence here and there but it kept getting in, night after night, so I resurrected my old "Fido-Shock" electric fence charger and added a series of four hot wires, just outside the chicken wire, as a little extra deterrent. So far, so good.
If I had it to do over again, I'd scrape up the money and buy new chicken wire, or better yet, 1/2" galvanized hardware cloth, for the perimeter fence. I also think I should have used 3/4 inch conduit instead of 1/2 inch, although it's already made it through some strong winds with no problem. I also wish I had rigged the netting support with the same 17 gauge galvanized wire I used for the electric fence--but the tie wire should still be fine. Splicing the netting together was a much bigger job than I had anticipated (two long seams for a total of approximately 260 feet of hand "stitching"), but 14 feet is as wide as it comes, so there was no way around it.
I had been thinking of keeping chickens inside the cage as well, but I also want to use it for growing squash, tomatoes, and other vegetables. My wife pointed out that chickens would gobble the veggies as fast as I could plant them, so I guess the chickens won't work out after all. Too bad--I was looking forward to having some.
The newly-planted figs seem to be growing nicely, although leaf-cutter ants (another plague for Tucson gardeners) attacked my Black Madeira. They couldn't snip through the thick petioles like they do on most trees, but they still managed to chew up all the leaf edges. Oh well--no real harm done.
All in all it has been a very cost-effective and fun project, and I'm optimistic it will work out quite well. I'm really looking forward to eating a lot of figs in a few years!