Penguins are an indicator of the health of our watery planet, and if they are unable to survive, we had better take… — Roger Tory Peterson Copy Share Image
Birds are indicators of the environment. If they are in trouble, we know we'll soon be in trouble. — Roger Tory Peterson Copy Share Image
Butterflies may be better indicators of the health of our environment than birds. — Roger Tory Peterson Copy Share Image
Birds ... are sensitive indicators of the environment, a sort of "ecological litmus paper," ... The observation and recording of bird populations… — Roger Tory Peterson Copy Share Image
More birds have adapted to a changing world than have failed. Very few have the narrow tolerance of the ivory-billed woodpecker or the Bachman's… — Roger Tory Peterson Copy Share Image
The philosophy that I have worked under most of my life is that the serious study of natural history is an activity which has… — Roger Tory Peterson Copy Share Image
Penguins are an indicator of the health of our watery planet, and if they are unable to survive, we had better take notice or… — Roger Tory Peterson Copy Share Image
I can recognize the calls of practically every bird in North America. There are some in Africa I don't know, though — Roger Tory Peterson Copy Share Image
Butterflies are very interesting. Here these things are little grubs for a while. And then they go into a little coffin. There they are… — Roger Tory Peterson Copy Share Image
Birds are indicators of the environment. If they are in trouble, we know we'll soon be in trouble. — Roger Tory Peterson Copy Share Image
Vultures are homely, but they clean up all the garbage and that's good. And they're elegant in the sky. — Roger Tory Peterson Copy Share Image
Butterflies may be better indicators of the health of our environment than birds. — Roger Tory Peterson Copy Share Image
Of all the various out-door recreations I have tried, when it comes to genuine, exciting sport, give me hunting with a camera… — Roger Tory Peterson Copy Share Image
Birds ... are sensitive indicators of the environment, a sort of "ecological litmus paper," ... The observation and recording of bird populations over time… — Roger Tory Peterson Copy Share Image
