Funny thing is many species of birds do get extremely drunk in the wild. They really enjoy eating fruit that is extremely ripe. This fruit already has a high alcohol content in it from the fermentation process. They don't like the fruit when it is at the right eating stage for us but wait until it is starting to ferment.
The other week there was a show on tv here showing flocks of Rainbow Lorikeets that had pigged out on over ripe fruit. There were birds everywhere falling over or just lying there in an alcoholic stupor. The locals take them to the local vets who check them over and put them into, lol you can only call it a drunk tank, and wait for them to sober up so they can be re-released.