Researchers noticed songbird's that were exposed to non-lethal chemicals had inconsistencies in their song.
Doctor Sara DeLeon, of Cornell University's Laboratory of Ornithology, and colleagues studied nesting songbirds along the Hudson River, an area known for PCB contamination from electronic manufacturing companies, a New York Sea Grant press release reported.
Polychlorinated biphenyls (PCBs) are "synthetic chemical pollutants" that have been shown to cause significant developmental problems in both humans and animals.
"Dr. DeLeon's work would have brought a smile to the face of Rachel Carson," William Wise, Interim Director of New York Sea Grant, said. "This type of dedicated field research can tease out the impact of organic contaminants in the environment on creatures that are known to all of us. Sara and colleagues are drawing the connections between contaminant, animal behavior and, ultimately, a population's health."
The songbirds feed their offspring aquatic insects that have been contaminated with PCBs. Some of these birds even munch on the bugs for their entire lives.
"Our results indicate that black-capped chickadees and song sparrows have higher total blood PCBs in regions with higher historic PCB contamination. The two bird species varied substantially in their congener-specific PCB profiles; within sites, song sparrows showed a significantly higher proportion of lower chlorinated PCBs, while black-capped chickadees had higher proportions of highly chlorinated PCBs," the authors wrote.
The black-capped chickadees were found to have a "greater variability in song," and a change in their "glide" in the first not of their song that goes, ""fee-bee, fee-bee." Song sparrows have more elaborate songs, and showed "high performance trills" that may indicate the presence of a different type of PCB.
"Thus, PCBs may affect song production, an important component of communication in birds," the authors said. "The ramifications of changes in song quality for bird populations may extend the toxic effects of environmental PCB pollution."
WATCH:
