Bird Populations and Environmental Changes: Can Birds Be Bio-indicators?

Abstract

ies of Regional Reports and Christmas Bird Counts pubhshed each year in American Birds is that bird populations change.Some of these changes consist merely of extralimital occurrences of a few individuals, but others involve large-scale changes in the abundance or distribution of species.Can such changes be used to monitor changes in the environment, especially aspects of environmental degredation that may not yet be apparent to us?To use bird populations as indicators of environmental changes, we must be confident that the population changes we have recorded are real and not artifacts of sampling, and we must be able to link those changes to specific perturbalaons in the birds' environment.