Each week we write about the science behind environmental
protection. Previous Science Wednesdays. About the Author: Karl
Berg is currently a Ph.D. student at Cornell University in
Ithaca, NY, and is looking forward to a career that will combine
his interests in animal behavior and conservation. His master’s
research was funded by an EPA Science to Achieve Results (STAR)
Graduate Research Fellowship. Bird populations have long been
viewed as “canaries in the coal mine” for indicating changes in
environmental health. As EPA’s Report on the Environment states,
“changes in bird populations reflect changes in landscape and
habitat, food availability and quality, toxic exposure, and
climate.” Because this is so important, annual bird counts to
document population changes are conducted by the North American
Breeding Bird Survey. If the timing of the species’ calls is
staggered, birds could be undercounted, which is why I wanted to
find an improved method to monitor bird populations to better
understand how they are