>bird sing? Take away its water.
This is just a wild theory. But the other night, I posted this pic from SIGNS.
Do you think that perhaps they've been drinking PURE water for so many generations that perhaps, we "feeders" have developed a tolerance, if you will, to the poisons in the water. They have no tolerance, since they have been avoiding poison water for a very long time.
Maybe "normal" water is poisonous to them? And when out of their safe zones, do they die of thirst or die of some disease?
Crazy thought, I know.