Many years ago, it was standard practice for coal miners to take canaries or other finches into the mines. These birds saved many lives by detecting and reacting to poison gas long before miners could detect it. When a miner saw his bird go down, they would evacuate the mine. Birds would usually recover for work another day. Actually, a lot.
Birds continue to serve as guardians of our environment.
Just as they protected workers in the coal mines, they can protect us from unseen, insidious dangers in our environment - if we are willing to listen. Their lives are a reflection of our own. Back in the 1960's, when bird populations began experiencing drastic declines, we recognized we were poisoning our environment with dangerous chemicals such as DDT and PCB's. Because of birds' poor reproduction and abnormal eggs, we recognized that these chemicals had begun their onslaught on the human population as well. When these chemicals were outlawed, birds began to make a steady, albeit slow, comeback.