)
Kiwibird, I'm not sure that you need a health certificate to transport birds in/out of California and Nevada as long as the birds you have are not illegal within California (i.e. quakers). I grew up mostly in California and had to drive into Nevada to go shopping for anything. Small town with a population of 90 and the closest major cities are 30 minutes east in another state (that I now live in). When I lived in California, my budgies and first cockatiel came from Nevada. I also had a lovebird, bourke parakeets and a turquoisine that also came from Nevada. Not once did I require any kind of certificate when crossing the border!
When I got Charlie, I was living in Nevada by then (not a far move from where I was previously living) and he was in California. There are only check stations going into California, not leaving the state, so once again he didn't require anything.
When Jayde came to me, she did leave Ohio after getting a health certificate, however this is Ohio state law, not Nevada! I had no issue picking her up at the airport and walking right out with her!
So if you were to get a bird in California or Nevada, I can't see any problems with that.