Any live animal needs to be picked up -- not just from Metzer. I called our postmaster as soon as I placed the order and explained I was expecting live animals. They were to be shipped on x date and arrive on y date. I asked them to call me as soon as they received them. They asked that I call with tracking as soon as they were shipped so they could monitor the package.
I monitored the package and so did my local post office. My heart stopped when I checked the tracking information on Wednesday and they were labeled "Dead on Arrival"... But I had bothered the postmaster enough that he gave me his direct line. I called and he said it was a lag between scanning from being unloaded and him scanning the package as arrived. He had them, so I drove the 30 minutes and knocked at the side door an hour before they officially opened... Just like they said.
Rural post offices are accustomed to shipping birds. If you live in a city, you may want to explain that you need to be called asap or the birds could die... But politely -- the last thing you want to do is insult them.