Hello We have wisteria in the back yard and the girls eat the dried leaves with out any issues at all. If they pick something up and don't like the taste of it they won't eat it and leave it alone. Mine have picked up the green leaves off the wisteria tasted and then like"spit" it out. Funny girls lol...
Same here, we have plants on our property that are listed as toxic but I have never had any problems with my birds (this includes Muscovy ducks) eating them. There are certain plants they like and will savage until the plant is dead and others they seem to know not to bother with.
As others have suggested, I am not even sure if the plants work the same in birds as in humans because wild birds would certainly be more scarce than they are if poisonous plants were a major threat.