Appendix D. A depiction of detection indices (percentage of years when a species was detected on Breeding Bird Survey routes that were sampled at least seven times during 1994–2003) for 10 songbird species vs. mean human footprint class (minimal to high human footprint influence).

A depiction of detection indices (percentage of years when a species was detected on Breeding Bird Survey routes that were sampled at least seven times during 1994–2003) for 10 songbird species vs. mean human footprint class (minimal to high human footprint influence).