Skip to main content
USGS - science for a changing world


Natalie K Karouna

Research Ecologist

Patuxent Wildlife Research Center

Office Phone: 301-497-5724
ORCID: 0000-0001-7127-033X

Supervisor: Linda A Weir
A site in north eastern MI, Oscoda Township, has some of the highest recorded exposure in birds to perfluorinated substances (PFASs) in the U.S. Some egg and plasma concentrations at that location exceeded the lowest reproductive effect threshold established for two avian laboratory species. The objectives of this study were to determine whether there were reproductive effects or physiological responses in a model bird species, the tree swallow (Tachycineta bicolor), associated with this extremely high exposure to PFASs. The lack of exposure above background to other contaminants at this site allowed for an assessment of PFAS effects without the complication that responses may be caused by other contaminants. A...
- Observations of test subjects and hatching data - Body weight, organ/tissue weights - Biomarker data (oxidative stress indicators, oxidative DNA damage, thyroid hormones, histological findings) in various tissues - Chemical residues in tissues
- Observations of test subjects, - Body weight, organ/tissue weights - Biomarker data (oxidative DNA damage, thyroid hormones, corticosterone, gene expression) in various tissues - Residues as percent of administered dose - Tissues to plasma rations - Metabolites and ratios - Elimination half-lives
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact