Bird Food Redux

For one UVA researcher, clues about the health of the environment lie in examining the feathers and vomit of birds.

Charles Clarkson (Grad ’14), a doctoral candidate in environmental sciences, has compared bird populations on Virginia’s Eastern Shore with those in New York Harbor by poring over regurgitations and feathers of the nestlings of two species: the glossy ibis and the double-crested cormorant. The former gets its food by probing through mud; the latter, from a variety of fish species in fresh, brackish or salt water.

By analyzing stomach contents—nestlings regurgitate as a defense mechanism—Clarkson can determine aspects of diet, such as mercury levels in fish. Feathers have bars that give clues to growth patterns and whether the birds are developing normally or slower because of environmental stress.

“Initial indications seem to be that the feather growth bars are wider in Virginia birds than New York birds, which likely means better nutritional conditions on the Eastern Shore, whether from dietary abundance or quality,” Clarkson says.

Though collecting bird vomit might seem grisly, the research is bearing fruit.

“I can tell a lot about the environments in which they live and, likewise, the overall health of the overall environments in which we all live,” Clarkson says.