Birds ... are sensitive indicators of the environment, a sort of "ecological litmus paper," ... The observation and recording of bird populations over time lead inevitably to environmental awareness and can signal impending changes.

Birds have wings; they're free; they can fly where they want when they want. They have the kind of mobility many people envy.

Birds, it must be admitted, are the most exciting and most deserving of the vertebrates; they are perhaps the best entre into the study of natural history, and a very good wedge into conservation awareness.

The more you look, the more you will see.

I can recognize the calls of practically every bird in North America. There are some in Africa I don't know, though

Birds are, perhaps, the most eloquent expression of reality.

Birds are an ecological litmus paper.