Animal tissues should reflect the local precipitation isotope ratios of hydrogen (1H) and Deuterium (2H, or “D”) (δD). We found that nestling American Kestrels had relatively low δD values in their claws (δDc) compared to adults from the same area. Growth rates could possibly influence uptake of hydrogen isotopes during tissue development. To test this hypothesis, we examined the δDc of nestlings with different growth rates. We predicted that fast growing nestlings would show lower δDc due to increased uptake of 1H, while slow growing nestlings would show higher δDc. We collected small claw clipping samples and morphometrics from birds ranging from 21 to 25 days old. Claw samples were washed, weighed, pyrolyzed through gas chromatography and analyzed by mass spectrometer to obtain δDc. Results from this project will show if growth rates can explain the differences in δDc between adult and nestling American Kestrels.
Available at: http://works.bepress.com/matthew_kohn/61/