"Wild" means that the bird's occurrence at the time and place of observation is not because it, or its recent ancestors, as ever been transported or otherwise assisted by man.
-Interpretation of ABA Rule 3
We all agree that global warming is caused my man, right? If birds start showing up in strange new locations because those locations now have more suitable climates because of climate change, are those birds considered to be "otherwise assisted by man"?
No, because that's crazy. Hummingbirds that over-winter in northern climes subsisting on feeders are countable, and birds that cross on ships are countable.
I'm just thinking about it because I've been thinking a lot about Rule 3, namely how hard it is for bird records committees to judge whether a bird is an escapee or a wild bird. Okay, okay, I'm upset that I drove forever and missed the Chaffinch today. Are you happy? I missed the Chaffinch. I don't even care.
But seriously, the escapee/wild problem is the biggest problem facing records committees, correct? How could it not be? If a bird - a Common Chaffinch, say - is found in an odd place - I don't know, like, western New Jersey - and it doesn't have any obvious marks of confinement, how can the correct answer possibly be determined? If both potential explanations - escapee or vagrant - are possible then anything after that is a guess. Informed or not, without further evidence any decision is just playing the odds.
I don't know much about the subject, but it's interesting. I'm going to try to work on some posts coming up here to tackle the issue. Hope they'll be showing up soon.