Why don't you try to put cookie in with the other birds at night first and see if they accept it okay. Then if they seem to be accepting it let it out with them in a few days. I'm not sure if the dog would leave it alone since obviously it isn't going to move as fast.
I'm giving up!!! Last week my two year old $800 dryer quit working. I'm still waiting for the replacement part to come in. Then this morning my 6 month old newest freezer stopped working. What in the world is going on? Luckily the freezer was still under warranty. I wasn't as lucky on the dryer.
that really stinks about your appliances!!!
I remember you having suggested to put new birds in with the rest of the flock at night. I'll try that tonight and see what happens.