Yes, but even if you take into account regional temperatures over land like in Brazil or Florida vs. New York, I don't see how 1 or 2 degrees F would have a bir

Yes, but even if you take into account regional temperatures over land like in Brazil or Florida vs. New York, I don't see how 1 or 2 degrees F would have a bird go that much further North when it is only for a few months. I proposed another possible cause - deforestation or food supply, since they are from places like Brazil and Florida, and they have been spotted in NY before this, and I still don't see how a few degrees is enough to have a bird go 1500 to 3000 miles further North in substantial numbers.